/* Expands front end tree to back end RTL for GCC
- Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
- 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
- 2010, 2011, 2012 Free Software Foundation, Inc.
+ Copyright (C) 1987-2020 Free Software Foundation, Inc.
This file is part of GCC.
#include "config.h"
#include "system.h"
#include "coretypes.h"
-#include "tm.h"
-
+#include "backend.h"
+#include "target.h"
#include "rtl.h"
-#include "hard-reg-set.h"
#include "tree.h"
-#include "tm_p.h"
-#include "flags.h"
-#include "except.h"
-#include "function.h"
-#include "insn-config.h"
-#include "expr.h"
-#include "libfuncs.h"
-#include "recog.h"
-#include "machmode.h"
-#include "diagnostic-core.h"
-#include "output.h"
-#include "ggc.h"
-#include "langhooks.h"
+#include "gimple.h"
+#include "cfghooks.h"
#include "predict.h"
+#include "memmodel.h"
+#include "tm_p.h"
#include "optabs.h"
-#include "target.h"
-#include "gimple.h"
#include "regs.h"
-#include "alloc-pool.h"
+#include "emit-rtl.h"
#include "pretty-print.h"
-#include "bitmap.h"
-#include "params.h"
+#include "diagnostic-core.h"
+
+#include "fold-const.h"
+#include "varasm.h"
+#include "stor-layout.h"
+#include "dojump.h"
+#include "explow.h"
+#include "stmt.h"
+#include "expr.h"
+#include "langhooks.h"
+#include "cfganal.h"
+#include "tree-cfg.h"
+#include "dumpfile.h"
+#include "builtins.h"
\f
/* Functions and data structures for expanding case statements. */
as in C, the high and low limits are the same.
We start with a vector of case nodes sorted in ascending order, and
- the default label as the last element in the vector. Before expanding
- to RTL, we transform this vector into a list linked via the RIGHT
- fields in the case_node struct. Nodes with higher case values are
- later in the list.
-
- Switch statements can be output in three forms. A branch table is
- used if there are more than a few labels and the labels are dense
- within the range between the smallest and largest case value. If a
- branch table is used, no further manipulations are done with the case
- node chain.
-
- The alternative to the use of a branch table is to generate a series
- of compare and jump insns. When that is done, we use the LEFT, RIGHT,
- and PARENT fields to hold a binary tree. Initially the tree is
- totally unbalanced, with everything on the right. We balance the tree
- with nodes on the left having lower case values than the parent
- and nodes on the right having higher values. We then output the tree
- in order.
-
- For very small, suitable switch statements, we can generate a series
- of simple bit test and branches instead. */
-
-struct case_node
-{
- struct case_node *left; /* Left son in binary tree */
- struct case_node *right; /* Right son in binary tree; also node chain */
- struct case_node *parent; /* Parent of node in binary tree */
- tree low; /* Lowest index value for this label */
- tree high; /* Highest index value for this label */
- tree code_label; /* Label to jump to when node matches */
-};
+ the default label as the last element in the vector.
-typedef struct case_node case_node;
-typedef struct case_node *case_node_ptr;
+ Switch statements are expanded in jump table form.
+*/
+
+class simple_case_node
+{
+public:
+ simple_case_node (tree low, tree high, tree code_label):
+ m_low (low), m_high (high), m_code_label (code_label)
+ {}
+
+ /* Lowest index value for this label. */
+ tree m_low;
+ /* Highest index value for this label. */
+ tree m_high;
+ /* Label to jump to when node matches. */
+ tree m_code_label;
+};
\f
-static int n_occurrences (int, const char *);
-static bool tree_conflicts_with_clobbers_p (tree, HARD_REG_SET *);
-static void expand_nl_goto_receiver (void);
-static bool check_operand_nalternatives (tree, tree);
static bool check_unique_operand_names (tree, tree, tree);
static char *resolve_operand_name_1 (char *, tree, tree, tree);
-static void expand_null_return_1 (void);
-static void expand_value_return (rtx);
-static void balance_case_nodes (case_node_ptr *, case_node_ptr);
-static int node_has_low_bound (case_node_ptr, tree);
-static int node_has_high_bound (case_node_ptr, tree);
-static int node_is_bounded (case_node_ptr, tree);
-static void emit_case_nodes (rtx, case_node_ptr, rtx, tree);
-static struct case_node *add_case_node (struct case_node *, tree,
- tree, tree, tree, alloc_pool);
-
\f
/* Return the rtx-label that corresponds to a LABEL_DECL,
creating it if necessary. */
-rtx
+rtx_insn *
label_rtx (tree label)
{
gcc_assert (TREE_CODE (label) == LABEL_DECL);
if (!DECL_RTL_SET_P (label))
{
- rtx r = gen_label_rtx ();
+ rtx_code_label *r = gen_label_rtx ();
SET_DECL_RTL (label, r);
if (FORCED_LABEL (label) || DECL_NONLOCAL (label))
LABEL_PRESERVE_P (r) = 1;
}
- return DECL_RTL (label);
+ return as_a <rtx_insn *> (DECL_RTL (label));
}
/* As above, but also put it on the forced-reference list of the
function that contains it. */
-rtx
+rtx_insn *
force_label_rtx (tree label)
{
- rtx ref = label_rtx (label);
+ rtx_insn *ref = label_rtx (label);
tree function = decl_function_context (label);
gcc_assert (function);
- forced_labels = gen_rtx_EXPR_LIST (VOIDmode, ref, forced_labels);
+ vec_safe_push (forced_labels, ref);
return ref;
}
-/* Add an unconditional jump to LABEL as the next sequential instruction. */
-
-void
-emit_jump (rtx label)
+/* As label_rtx, but ensures (in check build), that returned value is
+ an existing label (i.e. rtx with code CODE_LABEL). */
+rtx_code_label *
+jump_target_rtx (tree label)
{
- do_pending_stack_adjust ();
- emit_jump_insn (gen_jump (label));
- emit_barrier ();
+ return as_a <rtx_code_label *> (label_rtx (label));
}
-/* Emit code to jump to the address
- specified by the pointer expression EXP. */
+/* Add an unconditional jump to LABEL as the next sequential instruction. */
void
-expand_computed_goto (tree exp)
+emit_jump (rtx label)
{
- rtx x = expand_normal (exp);
-
- x = convert_memory_address (Pmode, x);
-
do_pending_stack_adjust ();
- emit_indirect_jump (x);
+ emit_jump_insn (targetm.gen_jump (label));
+ emit_barrier ();
}
\f
/* Handle goto statements and the labels that they can go to. */
void
expand_label (tree label)
{
- rtx label_r = label_rtx (label);
+ rtx_code_label *label_r = jump_target_rtx (label);
do_pending_stack_adjust ();
emit_label (label_r);
if (DECL_NONLOCAL (label))
{
- expand_nl_goto_receiver ();
+ expand_builtin_setjmp_receiver (NULL);
nonlocal_goto_handler_labels
- = gen_rtx_EXPR_LIST (VOIDmode, label_r,
+ = gen_rtx_INSN_LIST (VOIDmode, label_r,
nonlocal_goto_handler_labels);
}
if (FORCED_LABEL (label))
- forced_labels = gen_rtx_EXPR_LIST (VOIDmode, label_r, forced_labels);
+ vec_safe_push<rtx_insn *> (forced_labels, label_r);
if (DECL_NONLOCAL (label) || FORCED_LABEL (label))
maybe_set_first_label_num (label_r);
}
-
-/* Generate RTL code for a `goto' statement with target label LABEL.
- LABEL should be a LABEL_DECL tree node that was or will later be
- defined with `expand_label'. */
-
-void
-expand_goto (tree label)
-{
-#ifdef ENABLE_CHECKING
- /* Check for a nonlocal goto to a containing function. Should have
- gotten translated to __builtin_nonlocal_goto. */
- tree context = decl_function_context (label);
- gcc_assert (!context || context == current_function_decl);
-#endif
-
- emit_jump (label_rtx (label));
-}
\f
-/* Return the number of times character C occurs in string S. */
-static int
-n_occurrences (int c, const char *s)
-{
- int n = 0;
- while (*s)
- n += (*s++ == c);
- return n;
-}
-\f
-/* Generate RTL for an asm statement (explicit assembler code).
- STRING is a STRING_CST node containing the assembler code text,
- or an ADDR_EXPR containing a STRING_CST. VOL nonzero means the
- insn is volatile; don't optimize it. */
-
-static void
-expand_asm_loc (tree string, int vol, location_t locus)
-{
- rtx body;
-
- if (TREE_CODE (string) == ADDR_EXPR)
- string = TREE_OPERAND (string, 0);
-
- body = gen_rtx_ASM_INPUT_loc (VOIDmode,
- ggc_strdup (TREE_STRING_POINTER (string)),
- locus);
-
- MEM_VOLATILE_P (body) = vol;
-
- emit_insn (body);
-}
-
/* Parse the output constraint pointed to by *CONSTRAINT_P. It is the
OPERAND_NUMth output operand, indexed from zero. There are NINPUTS
inputs and NOUTPUTS outputs to this extended-asm. Upon return,
}
/* Loop through the constraint string. */
- for (p = constraint + 1; *p; p += CONSTRAINT_LEN (*p, p))
- switch (*p)
- {
- case '+':
- case '=':
- error ("operand constraint contains incorrectly positioned "
- "%<+%> or %<=%>");
- return false;
-
- case '%':
- if (operand_num + 1 == ninputs + noutputs)
- {
- error ("%<%%%> constraint used with last operand");
- return false;
- }
- break;
-
- case 'V': case TARGET_MEM_CONSTRAINT: case 'o':
- *allows_mem = true;
- break;
-
- case '?': case '!': case '*': case '&': case '#':
- case 'E': case 'F': case 'G': case 'H':
- case 's': case 'i': case 'n':
- case 'I': case 'J': case 'K': case 'L': case 'M':
- case 'N': case 'O': case 'P': case ',':
- break;
-
- case '0': case '1': case '2': case '3': case '4':
- case '5': case '6': case '7': case '8': case '9':
- case '[':
- error ("matching constraint not valid in output operand");
- return false;
+ for (p = constraint + 1; *p; )
+ {
+ switch (*p)
+ {
+ case '+':
+ case '=':
+ error ("operand constraint contains incorrectly positioned "
+ "%<+%> or %<=%>");
+ return false;
- case '<': case '>':
- /* ??? Before flow, auto inc/dec insns are not supposed to exist,
- excepting those that expand_call created. So match memory
- and hope. */
- *allows_mem = true;
- break;
+ case '%':
+ if (operand_num + 1 == ninputs + noutputs)
+ {
+ error ("%<%%%> constraint used with last operand");
+ return false;
+ }
+ break;
- case 'g': case 'X':
- *allows_reg = true;
- *allows_mem = true;
- break;
+ case '?': case '!': case '*': case '&': case '#':
+ case '$': case '^':
+ case 'E': case 'F': case 'G': case 'H':
+ case 's': case 'i': case 'n':
+ case 'I': case 'J': case 'K': case 'L': case 'M':
+ case 'N': case 'O': case 'P': case ',':
+ break;
- case 'p': case 'r':
- *allows_reg = true;
- break;
+ case '0': case '1': case '2': case '3': case '4':
+ case '5': case '6': case '7': case '8': case '9':
+ case '[':
+ error ("matching constraint not valid in output operand");
+ return false;
- default:
- if (!ISALPHA (*p))
+ case '<': case '>':
+ /* ??? Before flow, auto inc/dec insns are not supposed to exist,
+ excepting those that expand_call created. So match memory
+ and hope. */
+ *allows_mem = true;
break;
- if (REG_CLASS_FROM_CONSTRAINT (*p, p) != NO_REGS)
- *allows_reg = true;
-#ifdef EXTRA_CONSTRAINT_STR
- else if (EXTRA_ADDRESS_CONSTRAINT (*p, p))
+
+ case 'g': case 'X':
*allows_reg = true;
- else if (EXTRA_MEMORY_CONSTRAINT (*p, p))
*allows_mem = true;
- else
- {
- /* Otherwise we can't assume anything about the nature of
- the constraint except that it isn't purely registers.
- Treat it like "g" and hope for the best. */
+ break;
+
+ default:
+ if (!ISALPHA (*p))
+ break;
+ enum constraint_num cn = lookup_constraint (p);
+ if (reg_class_for_constraint (cn) != NO_REGS
+ || insn_extra_address_constraint (cn))
*allows_reg = true;
+ else if (insn_extra_memory_constraint (cn))
*allows_mem = true;
- }
-#endif
- break;
- }
+ else
+ insn_extra_constraint_allows_reg_mem (cn, allows_reg, allows_mem);
+ break;
+ }
+
+ for (size_t len = CONSTRAINT_LEN (*p, p); len; len--, p++)
+ if (*p == '\0')
+ break;
+ }
return true;
}
}
break;
- case 'V': case TARGET_MEM_CONSTRAINT: case 'o':
- *allows_mem = true;
- break;
-
case '<': case '>':
case '?': case '!': case '*': case '#':
+ case '$': case '^':
case 'E': case 'F': case 'G': case 'H':
case 's': case 'i': case 'n':
case 'I': case 'J': case 'K': case 'L': case 'M':
}
/* Fall through. */
- case 'p': case 'r':
- *allows_reg = true;
- break;
-
case 'g': case 'X':
*allows_reg = true;
*allows_mem = true;
error ("invalid punctuation %qc in constraint", constraint[j]);
return false;
}
- if (REG_CLASS_FROM_CONSTRAINT (constraint[j], constraint + j)
- != NO_REGS)
- *allows_reg = true;
-#ifdef EXTRA_CONSTRAINT_STR
- else if (EXTRA_ADDRESS_CONSTRAINT (constraint[j], constraint + j))
+ enum constraint_num cn = lookup_constraint (constraint + j);
+ if (reg_class_for_constraint (cn) != NO_REGS
+ || insn_extra_address_constraint (cn))
*allows_reg = true;
- else if (EXTRA_MEMORY_CONSTRAINT (constraint[j], constraint + j))
+ else if (insn_extra_memory_constraint (cn)
+ || insn_extra_special_memory_constraint (cn))
*allows_mem = true;
else
- {
- /* Otherwise we can't assume anything about the nature of
- the constraint except that it isn't purely registers.
- Treat it like "g" and hope for the best. */
- *allows_reg = true;
- *allows_mem = true;
- }
-#endif
+ insn_extra_constraint_allows_reg_mem (cn, allows_reg, allows_mem);
break;
}
tree decl = *declp;
const HARD_REG_SET *const regs = (const HARD_REG_SET *) data;
- if (TREE_CODE (decl) == VAR_DECL)
+ if (VAR_P (decl))
{
if (DECL_HARD_REGISTER (decl)
&& REG_P (DECL_RTL (decl))
return walk_tree (&decl, decl_overlaps_hard_reg_set_p, regs, NULL);
}
-/* Check for overlap between registers marked in CLOBBERED_REGS and
- anything inappropriate in T. Emit error and return the register
- variable definition for error, NULL_TREE for ok. */
+
+/* A subroutine of expand_asm_operands. Check that all operand names
+ are unique. Return true if so. We rely on the fact that these names
+ are identifiers, and so have been canonicalized by get_identifier,
+ so all we need are pointer comparisons. */
static bool
-tree_conflicts_with_clobbers_p (tree t, HARD_REG_SET *clobbered_regs)
+check_unique_operand_names (tree outputs, tree inputs, tree labels)
{
- /* Conflicts between asm-declared register variables and the clobber
- list are not allowed. */
- tree overlap = tree_overlaps_hard_reg_set (t, clobbered_regs);
+ tree i, j, i_name = NULL_TREE;
- if (overlap)
+ for (i = outputs; i ; i = TREE_CHAIN (i))
{
- error ("asm-specifier for variable %qE conflicts with asm clobber list",
- DECL_NAME (overlap));
+ i_name = TREE_PURPOSE (TREE_PURPOSE (i));
+ if (! i_name)
+ continue;
- /* Reset registerness to stop multiple errors emitted for a single
- variable. */
- DECL_REGISTER (overlap) = 0;
- return true;
+ for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
+ if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
+ goto failure;
}
- return false;
-}
-
-/* Generate RTL for an asm statement with arguments.
- STRING is the instruction template.
- OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
- Each output or input has an expression in the TREE_VALUE and
- a tree list in TREE_PURPOSE which in turn contains a constraint
- name in TREE_VALUE (or NULL_TREE) and a constraint string
- in TREE_PURPOSE.
- CLOBBERS is a list of STRING_CST nodes each naming a hard register
- that is clobbered by this insn.
-
- Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
- Some elements of OUTPUTS may be replaced with trees representing temporary
- values. The caller should copy those temporary values to the originally
- specified lvalues.
-
- VOL nonzero means the insn is volatile; don't optimize it. */
-
-static void
-expand_asm_operands (tree string, tree outputs, tree inputs,
- tree clobbers, tree labels, int vol, location_t locus)
-{
- rtvec argvec, constraintvec, labelvec;
- rtx body;
- int ninputs = list_length (inputs);
- int noutputs = list_length (outputs);
- int nlabels = list_length (labels);
- int ninout;
- int nclobbers;
- HARD_REG_SET clobbered_regs;
- int clobber_conflict_found = 0;
- tree tail;
- tree t;
- int i;
- /* Vector of RTX's of evaluated output operands. */
- rtx *output_rtx = XALLOCAVEC (rtx, noutputs);
- int *inout_opnum = XALLOCAVEC (int, noutputs);
- rtx *real_output_rtx = XALLOCAVEC (rtx, noutputs);
- enum machine_mode *inout_mode = XALLOCAVEC (enum machine_mode, noutputs);
- const char **constraints = XALLOCAVEC (const char *, noutputs + ninputs);
- int old_generating_concat_p = generating_concat_p;
-
- /* An ASM with no outputs needs to be treated as volatile, for now. */
- if (noutputs == 0)
- vol = 1;
-
- if (! check_operand_nalternatives (outputs, inputs))
- return;
-
- string = resolve_asm_operand_names (string, outputs, inputs, labels);
-
- /* Collect constraints. */
- i = 0;
- for (t = outputs; t ; t = TREE_CHAIN (t), i++)
- constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
- for (t = inputs; t ; t = TREE_CHAIN (t), i++)
- constraints[i] = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
-
- /* Sometimes we wish to automatically clobber registers across an asm.
- Case in point is when the i386 backend moved from cc0 to a hard reg --
- maintaining source-level compatibility means automatically clobbering
- the flags register. */
- clobbers = targetm.md_asm_clobbers (outputs, inputs, clobbers);
-
- /* Count the number of meaningful clobbered registers, ignoring what
- we would ignore later. */
- nclobbers = 0;
- CLEAR_HARD_REG_SET (clobbered_regs);
- for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
+ for (i = inputs; i ; i = TREE_CHAIN (i))
{
- const char *regname;
- int nregs;
-
- if (TREE_VALUE (tail) == error_mark_node)
- return;
- regname = TREE_STRING_POINTER (TREE_VALUE (tail));
-
- i = decode_reg_name_and_count (regname, &nregs);
- if (i == -4)
- ++nclobbers;
- else if (i == -2)
- error ("unknown register name %qs in %<asm%>", regname);
-
- /* Mark clobbered registers. */
- if (i >= 0)
- {
- int reg;
-
- for (reg = i; reg < i + nregs; reg++)
- {
- ++nclobbers;
-
- /* Clobbering the PIC register is an error. */
- if (reg == (int) PIC_OFFSET_TABLE_REGNUM)
- {
- error ("PIC register clobbered by %qs in %<asm%>", regname);
- return;
- }
+ i_name = TREE_PURPOSE (TREE_PURPOSE (i));
+ if (! i_name)
+ continue;
- SET_HARD_REG_BIT (clobbered_regs, reg);
- }
- }
+ for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
+ if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
+ goto failure;
+ for (j = outputs; j ; j = TREE_CHAIN (j))
+ if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
+ goto failure;
}
- /* First pass over inputs and outputs checks validity and sets
- mark_addressable if needed. */
-
- ninout = 0;
- for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
+ for (i = labels; i ; i = TREE_CHAIN (i))
{
- tree val = TREE_VALUE (tail);
- tree type = TREE_TYPE (val);
- const char *constraint;
- bool is_inout;
- bool allows_reg;
- bool allows_mem;
-
- /* If there's an erroneous arg, emit no insn. */
- if (type == error_mark_node)
- return;
-
- /* Try to parse the output constraint. If that fails, there's
- no point in going further. */
- constraint = constraints[i];
- if (!parse_output_constraint (&constraint, i, ninputs, noutputs,
- &allows_mem, &allows_reg, &is_inout))
- return;
-
- if (! allows_reg
- && (allows_mem
- || is_inout
- || (DECL_P (val)
- && REG_P (DECL_RTL (val))
- && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))))
- mark_addressable (val);
-
- if (is_inout)
- ninout++;
- }
+ i_name = TREE_PURPOSE (i);
+ if (! i_name)
+ continue;
- ninputs += ninout;
- if (ninputs + noutputs > MAX_RECOG_OPERANDS)
- {
- error ("more than %d operands in %<asm%>", MAX_RECOG_OPERANDS);
- return;
+ for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
+ if (simple_cst_equal (i_name, TREE_PURPOSE (j)))
+ goto failure;
+ for (j = inputs; j ; j = TREE_CHAIN (j))
+ if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
+ goto failure;
}
- for (i = 0, tail = inputs; tail; i++, tail = TREE_CHAIN (tail))
- {
- bool allows_reg, allows_mem;
- const char *constraint;
-
- /* If there's an erroneous arg, emit no insn, because the ASM_INPUT
- would get VOIDmode and that could cause a crash in reload. */
- if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node)
- return;
+ return true;
- constraint = constraints[i + noutputs];
- if (! parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
- constraints, &allows_mem, &allows_reg))
- return;
+ failure:
+ error ("duplicate %<asm%> operand name %qs", TREE_STRING_POINTER (i_name));
+ return false;
+}
- if (! allows_reg && allows_mem)
- mark_addressable (TREE_VALUE (tail));
- }
+/* Resolve the names of the operands in *POUTPUTS and *PINPUTS to numbers,
+ and replace the name expansions in STRING and in the constraints to
+ those numbers. This is generally done in the front end while creating
+ the ASM_EXPR generic tree that eventually becomes the GIMPLE_ASM. */
- /* Second pass evaluates arguments. */
+tree
+resolve_asm_operand_names (tree string, tree outputs, tree inputs, tree labels)
+{
+ char *buffer;
+ char *p;
+ const char *c;
+ tree t;
- /* Make sure stack is consistent for asm goto. */
- if (nlabels > 0)
- do_pending_stack_adjust ();
+ check_unique_operand_names (outputs, inputs, labels);
- ninout = 0;
- for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
+ /* Substitute [<name>] in input constraint strings. There should be no
+ named operands in output constraints. */
+ for (t = inputs; t ; t = TREE_CHAIN (t))
{
- tree val = TREE_VALUE (tail);
- tree type = TREE_TYPE (val);
- bool is_inout;
- bool allows_reg;
- bool allows_mem;
- rtx op;
- bool ok;
-
- ok = parse_output_constraint (&constraints[i], i, ninputs,
- noutputs, &allows_mem, &allows_reg,
- &is_inout);
- gcc_assert (ok);
-
- /* If an output operand is not a decl or indirect ref and our constraint
- allows a register, make a temporary to act as an intermediate.
- Make the asm insn write into that, then our caller will copy it to
- the real output operand. Likewise for promoted variables. */
-
- generating_concat_p = 0;
-
- real_output_rtx[i] = NULL_RTX;
- if ((TREE_CODE (val) == INDIRECT_REF
- && allows_mem)
- || (DECL_P (val)
- && (allows_mem || REG_P (DECL_RTL (val)))
- && ! (REG_P (DECL_RTL (val))
- && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type)))
- || ! allows_reg
- || is_inout)
- {
- op = expand_expr (val, NULL_RTX, VOIDmode, EXPAND_WRITE);
- if (MEM_P (op))
- op = validize_mem (op);
-
- if (! allows_reg && !MEM_P (op))
- error ("output number %d not directly addressable", i);
- if ((! allows_mem && MEM_P (op))
- || GET_CODE (op) == CONCAT)
- {
- real_output_rtx[i] = op;
- op = gen_reg_rtx (GET_MODE (op));
- if (is_inout)
- emit_move_insn (op, real_output_rtx[i]);
- }
- }
- else
+ c = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
+ if (strchr (c, '[') != NULL)
{
- op = assign_temp (type, 0, 1);
- op = validize_mem (op);
- if (!MEM_P (op) && TREE_CODE (TREE_VALUE (tail)) == SSA_NAME)
- set_reg_attrs_for_decl_rtl (SSA_NAME_VAR (TREE_VALUE (tail)), op);
- TREE_VALUE (tail) = make_tree (type, op);
+ p = buffer = xstrdup (c);
+ while ((p = strchr (p, '[')) != NULL)
+ p = resolve_operand_name_1 (p, outputs, inputs, NULL);
+ TREE_VALUE (TREE_PURPOSE (t))
+ = build_string (strlen (buffer), buffer);
+ free (buffer);
}
- output_rtx[i] = op;
-
- generating_concat_p = old_generating_concat_p;
+ }
- if (is_inout)
+ /* Now check for any needed substitutions in the template. */
+ c = TREE_STRING_POINTER (string);
+ while ((c = strchr (c, '%')) != NULL)
+ {
+ if (c[1] == '[')
+ break;
+ else if (ISALPHA (c[1]) && c[2] == '[')
+ break;
+ else
{
- inout_mode[ninout] = TYPE_MODE (type);
- inout_opnum[ninout++] = i;
+ c += 1 + (c[1] == '%');
+ continue;
}
-
- if (tree_conflicts_with_clobbers_p (val, &clobbered_regs))
- clobber_conflict_found = 1;
}
- /* Make vectors for the expression-rtx, constraint strings,
- and named operands. */
-
- argvec = rtvec_alloc (ninputs);
- constraintvec = rtvec_alloc (ninputs);
- labelvec = rtvec_alloc (nlabels);
-
- body = gen_rtx_ASM_OPERANDS ((noutputs == 0 ? VOIDmode
- : GET_MODE (output_rtx[0])),
- ggc_strdup (TREE_STRING_POINTER (string)),
- empty_string, 0, argvec, constraintvec,
- labelvec, locus);
-
- MEM_VOLATILE_P (body) = vol;
-
- /* Eval the inputs and put them into ARGVEC.
- Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
-
- for (i = 0, tail = inputs; tail; tail = TREE_CHAIN (tail), ++i)
+ if (c)
{
- bool allows_reg, allows_mem;
- const char *constraint;
- tree val, type;
- rtx op;
- bool ok;
-
- constraint = constraints[i + noutputs];
- ok = parse_input_constraint (&constraint, i, ninputs, noutputs, ninout,
- constraints, &allows_mem, &allows_reg);
- gcc_assert (ok);
+ /* OK, we need to make a copy so we can perform the substitutions.
+ Assume that we will not need extra space--we get to remove '['
+ and ']', which means we cannot have a problem until we have more
+ than 999 operands. */
+ buffer = xstrdup (TREE_STRING_POINTER (string));
+ p = buffer + (c - TREE_STRING_POINTER (string));
- generating_concat_p = 0;
-
- val = TREE_VALUE (tail);
- type = TREE_TYPE (val);
- /* EXPAND_INITIALIZER will not generate code for valid initializer
- constants, but will still generate code for other types of operand.
- This is the behavior we want for constant constraints. */
- op = expand_expr (val, NULL_RTX, VOIDmode,
- allows_reg ? EXPAND_NORMAL
- : allows_mem ? EXPAND_MEMORY
- : EXPAND_INITIALIZER);
-
- /* Never pass a CONCAT to an ASM. */
- if (GET_CODE (op) == CONCAT)
- op = force_reg (GET_MODE (op), op);
- else if (MEM_P (op))
- op = validize_mem (op);
-
- if (asm_operand_ok (op, constraint, NULL) <= 0)
+ while ((p = strchr (p, '%')) != NULL)
{
- if (allows_reg && TYPE_MODE (type) != BLKmode)
- op = force_reg (TYPE_MODE (type), op);
- else if (!allows_mem)
- warning (0, "asm operand %d probably doesn%'t match constraints",
- i + noutputs);
- else if (MEM_P (op))
+ if (p[1] == '[')
+ p += 1;
+ else if (ISALPHA (p[1]) && p[2] == '[')
+ p += 2;
+ else
{
- /* We won't recognize either volatile memory or memory
- with a queued address as available a memory_operand
- at this point. Ignore it: clearly this *is* a memory. */
+ p += 1 + (p[1] == '%');
+ continue;
}
- else
- gcc_unreachable ();
- }
- generating_concat_p = old_generating_concat_p;
- ASM_OPERANDS_INPUT (body, i) = op;
-
- ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, i)
- = gen_rtx_ASM_INPUT (TYPE_MODE (type),
- ggc_strdup (constraints[i + noutputs]));
+ p = resolve_operand_name_1 (p, outputs, inputs, labels);
+ }
- if (tree_conflicts_with_clobbers_p (val, &clobbered_regs))
- clobber_conflict_found = 1;
+ string = build_string (strlen (buffer), buffer);
+ free (buffer);
}
- /* Protect all the operands from the queue now that they have all been
- evaluated. */
-
- generating_concat_p = 0;
-
- /* For in-out operands, copy output rtx to input rtx. */
- for (i = 0; i < ninout; i++)
- {
- int j = inout_opnum[i];
- char buffer[16];
+ return string;
+}
- ASM_OPERANDS_INPUT (body, ninputs - ninout + i)
- = output_rtx[j];
-
- sprintf (buffer, "%d", j);
- ASM_OPERANDS_INPUT_CONSTRAINT_EXP (body, ninputs - ninout + i)
- = gen_rtx_ASM_INPUT (inout_mode[i], ggc_strdup (buffer));
- }
-
- /* Copy labels to the vector. */
- for (i = 0, tail = labels; i < nlabels; ++i, tail = TREE_CHAIN (tail))
- ASM_OPERANDS_LABEL (body, i)
- = gen_rtx_LABEL_REF (Pmode, label_rtx (TREE_VALUE (tail)));
-
- generating_concat_p = old_generating_concat_p;
-
- /* Now, for each output, construct an rtx
- (set OUTPUT (asm_operands INSN OUTPUTCONSTRAINT OUTPUTNUMBER
- ARGVEC CONSTRAINTS OPNAMES))
- If there is more than one, put them inside a PARALLEL. */
-
- if (nlabels > 0 && nclobbers == 0)
- {
- gcc_assert (noutputs == 0);
- emit_jump_insn (body);
- }
- else if (noutputs == 0 && nclobbers == 0)
- {
- /* No output operands: put in a raw ASM_OPERANDS rtx. */
- emit_insn (body);
- }
- else if (noutputs == 1 && nclobbers == 0)
- {
- ASM_OPERANDS_OUTPUT_CONSTRAINT (body) = ggc_strdup (constraints[0]);
- emit_insn (gen_rtx_SET (VOIDmode, output_rtx[0], body));
- }
- else
- {
- rtx obody = body;
- int num = noutputs;
-
- if (num == 0)
- num = 1;
-
- body = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num + nclobbers));
-
- /* For each output operand, store a SET. */
- for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
- {
- XVECEXP (body, 0, i)
- = gen_rtx_SET (VOIDmode,
- output_rtx[i],
- gen_rtx_ASM_OPERANDS
- (GET_MODE (output_rtx[i]),
- ggc_strdup (TREE_STRING_POINTER (string)),
- ggc_strdup (constraints[i]),
- i, argvec, constraintvec, labelvec, locus));
-
- MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol;
- }
-
- /* If there are no outputs (but there are some clobbers)
- store the bare ASM_OPERANDS into the PARALLEL. */
-
- if (i == 0)
- XVECEXP (body, 0, i++) = obody;
-
- /* Store (clobber REG) for each clobbered register specified. */
-
- for (tail = clobbers; tail; tail = TREE_CHAIN (tail))
- {
- const char *regname = TREE_STRING_POINTER (TREE_VALUE (tail));
- int reg, nregs;
- int j = decode_reg_name_and_count (regname, &nregs);
- rtx clobbered_reg;
-
- if (j < 0)
- {
- if (j == -3) /* `cc', which is not a register */
- continue;
-
- if (j == -4) /* `memory', don't cache memory across asm */
- {
- XVECEXP (body, 0, i++)
- = gen_rtx_CLOBBER (VOIDmode,
- gen_rtx_MEM
- (BLKmode,
- gen_rtx_SCRATCH (VOIDmode)));
- continue;
- }
-
- /* Ignore unknown register, error already signaled. */
- continue;
- }
-
- for (reg = j; reg < j + nregs; reg++)
- {
- /* Use QImode since that's guaranteed to clobber just
- * one reg. */
- clobbered_reg = gen_rtx_REG (QImode, reg);
-
- /* Do sanity check for overlap between clobbers and
- respectively input and outputs that hasn't been
- handled. Such overlap should have been detected and
- reported above. */
- if (!clobber_conflict_found)
- {
- int opno;
-
- /* We test the old body (obody) contents to avoid
- tripping over the under-construction body. */
- for (opno = 0; opno < noutputs; opno++)
- if (reg_overlap_mentioned_p (clobbered_reg,
- output_rtx[opno]))
- internal_error
- ("asm clobber conflict with output operand");
-
- for (opno = 0; opno < ninputs - ninout; opno++)
- if (reg_overlap_mentioned_p (clobbered_reg,
- ASM_OPERANDS_INPUT (obody,
- opno)))
- internal_error
- ("asm clobber conflict with input operand");
- }
-
- XVECEXP (body, 0, i++)
- = gen_rtx_CLOBBER (VOIDmode, clobbered_reg);
- }
- }
-
- if (nlabels > 0)
- emit_jump_insn (body);
- else
- emit_insn (body);
- }
-
- /* For any outputs that needed reloading into registers, spill them
- back to where they belong. */
- for (i = 0; i < noutputs; ++i)
- if (real_output_rtx[i])
- emit_move_insn (real_output_rtx[i], output_rtx[i]);
-
- crtl->has_asm_statement = 1;
- free_temp_slots ();
-}
-
-void
-expand_asm_stmt (gimple stmt)
-{
- int noutputs;
- tree outputs, tail, t;
- tree *o;
- size_t i, n;
- const char *s;
- tree str, out, in, cl, labels;
- location_t locus = gimple_location (stmt);
-
- /* Meh... convert the gimple asm operands into real tree lists.
- Eventually we should make all routines work on the vectors instead
- of relying on TREE_CHAIN. */
- out = NULL_TREE;
- n = gimple_asm_noutputs (stmt);
- if (n > 0)
- {
- t = out = gimple_asm_output_op (stmt, 0);
- for (i = 1; i < n; i++)
- t = TREE_CHAIN (t) = gimple_asm_output_op (stmt, i);
- }
-
- in = NULL_TREE;
- n = gimple_asm_ninputs (stmt);
- if (n > 0)
- {
- t = in = gimple_asm_input_op (stmt, 0);
- for (i = 1; i < n; i++)
- t = TREE_CHAIN (t) = gimple_asm_input_op (stmt, i);
- }
-
- cl = NULL_TREE;
- n = gimple_asm_nclobbers (stmt);
- if (n > 0)
- {
- t = cl = gimple_asm_clobber_op (stmt, 0);
- for (i = 1; i < n; i++)
- t = TREE_CHAIN (t) = gimple_asm_clobber_op (stmt, i);
- }
-
- labels = NULL_TREE;
- n = gimple_asm_nlabels (stmt);
- if (n > 0)
- {
- t = labels = gimple_asm_label_op (stmt, 0);
- for (i = 1; i < n; i++)
- t = TREE_CHAIN (t) = gimple_asm_label_op (stmt, i);
- }
-
- s = gimple_asm_string (stmt);
- str = build_string (strlen (s), s);
-
- if (gimple_asm_input_p (stmt))
- {
- expand_asm_loc (str, gimple_asm_volatile_p (stmt), locus);
- return;
- }
-
- outputs = out;
- noutputs = gimple_asm_noutputs (stmt);
- /* o[I] is the place that output number I should be written. */
- o = (tree *) alloca (noutputs * sizeof (tree));
-
- /* Record the contents of OUTPUTS before it is modified. */
- for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
- o[i] = TREE_VALUE (tail);
-
- /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
- OUTPUTS some trees for where the values were actually stored. */
- expand_asm_operands (str, outputs, in, cl, labels,
- gimple_asm_volatile_p (stmt), locus);
-
- /* Copy all the intermediate outputs into the specified outputs. */
- for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
- {
- if (o[i] != TREE_VALUE (tail))
- {
- expand_assignment (o[i], TREE_VALUE (tail), false);
- free_temp_slots ();
-
- /* Restore the original value so that it's correct the next
- time we expand this function. */
- TREE_VALUE (tail) = o[i];
- }
- }
-}
-
-/* A subroutine of expand_asm_operands. Check that all operands have
- the same number of alternatives. Return true if so. */
-
-static bool
-check_operand_nalternatives (tree outputs, tree inputs)
-{
- if (outputs || inputs)
- {
- tree tmp = TREE_PURPOSE (outputs ? outputs : inputs);
- int nalternatives
- = n_occurrences (',', TREE_STRING_POINTER (TREE_VALUE (tmp)));
- tree next = inputs;
-
- if (nalternatives + 1 > MAX_RECOG_ALTERNATIVES)
- {
- error ("too many alternatives in %<asm%>");
- return false;
- }
-
- tmp = outputs;
- while (tmp)
- {
- const char *constraint
- = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tmp)));
-
- if (n_occurrences (',', constraint) != nalternatives)
- {
- error ("operand constraints for %<asm%> differ "
- "in number of alternatives");
- return false;
- }
-
- if (TREE_CHAIN (tmp))
- tmp = TREE_CHAIN (tmp);
- else
- tmp = next, next = 0;
- }
- }
-
- return true;
-}
-
-/* A subroutine of expand_asm_operands. Check that all operand names
- are unique. Return true if so. We rely on the fact that these names
- are identifiers, and so have been canonicalized by get_identifier,
- so all we need are pointer comparisons. */
-
-static bool
-check_unique_operand_names (tree outputs, tree inputs, tree labels)
-{
- tree i, j, i_name = NULL_TREE;
-
- for (i = outputs; i ; i = TREE_CHAIN (i))
- {
- i_name = TREE_PURPOSE (TREE_PURPOSE (i));
- if (! i_name)
- continue;
-
- for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
- if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
- goto failure;
- }
-
- for (i = inputs; i ; i = TREE_CHAIN (i))
- {
- i_name = TREE_PURPOSE (TREE_PURPOSE (i));
- if (! i_name)
- continue;
-
- for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
- if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
- goto failure;
- for (j = outputs; j ; j = TREE_CHAIN (j))
- if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
- goto failure;
- }
-
- for (i = labels; i ; i = TREE_CHAIN (i))
- {
- i_name = TREE_PURPOSE (i);
- if (! i_name)
- continue;
-
- for (j = TREE_CHAIN (i); j ; j = TREE_CHAIN (j))
- if (simple_cst_equal (i_name, TREE_PURPOSE (j)))
- goto failure;
- for (j = inputs; j ; j = TREE_CHAIN (j))
- if (simple_cst_equal (i_name, TREE_PURPOSE (TREE_PURPOSE (j))))
- goto failure;
- }
-
- return true;
-
- failure:
- error ("duplicate asm operand name %qs", TREE_STRING_POINTER (i_name));
- return false;
-}
-
-/* A subroutine of expand_asm_operands. Resolve the names of the operands
- in *POUTPUTS and *PINPUTS to numbers, and replace the name expansions in
- STRING and in the constraints to those numbers. */
-
-tree
-resolve_asm_operand_names (tree string, tree outputs, tree inputs, tree labels)
-{
- char *buffer;
- char *p;
- const char *c;
- tree t;
-
- check_unique_operand_names (outputs, inputs, labels);
-
- /* Substitute [<name>] in input constraint strings. There should be no
- named operands in output constraints. */
- for (t = inputs; t ; t = TREE_CHAIN (t))
- {
- c = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (t)));
- if (strchr (c, '[') != NULL)
- {
- p = buffer = xstrdup (c);
- while ((p = strchr (p, '[')) != NULL)
- p = resolve_operand_name_1 (p, outputs, inputs, NULL);
- TREE_VALUE (TREE_PURPOSE (t))
- = build_string (strlen (buffer), buffer);
- free (buffer);
- }
- }
-
- /* Now check for any needed substitutions in the template. */
- c = TREE_STRING_POINTER (string);
- while ((c = strchr (c, '%')) != NULL)
- {
- if (c[1] == '[')
- break;
- else if (ISALPHA (c[1]) && c[2] == '[')
- break;
- else
- {
- c += 1 + (c[1] == '%');
- continue;
- }
- }
-
- if (c)
- {
- /* OK, we need to make a copy so we can perform the substitutions.
- Assume that we will not need extra space--we get to remove '['
- and ']', which means we cannot have a problem until we have more
- than 999 operands. */
- buffer = xstrdup (TREE_STRING_POINTER (string));
- p = buffer + (c - TREE_STRING_POINTER (string));
-
- while ((p = strchr (p, '%')) != NULL)
- {
- if (p[1] == '[')
- p += 1;
- else if (ISALPHA (p[1]) && p[2] == '[')
- p += 2;
- else
- {
- p += 1 + (p[1] == '%');
- continue;
- }
-
- p = resolve_operand_name_1 (p, outputs, inputs, labels);
- }
-
- string = build_string (strlen (buffer), buffer);
- free (buffer);
- }
-
- return string;
-}
-
-/* A subroutine of resolve_operand_names. P points to the '[' for a
- potential named operand of the form [<name>]. In place, replace
- the name and brackets with a number. Return a pointer to the
- balance of the string after substitution. */
+/* A subroutine of resolve_operand_names. P points to the '[' for a
+ potential named operand of the form [<name>]. In place, replace
+ the name and brackets with a number. Return a pointer to the
+ balance of the string after substitution. */
static char *
resolve_operand_name_1 (char *p, tree outputs, tree inputs, tree labels)
return p;
}
\f
-/* Generate RTL to evaluate the expression EXP. */
-
-void
-expand_expr_stmt (tree exp)
-{
- rtx value;
- tree type;
-
- value = expand_expr (exp, const0_rtx, VOIDmode, EXPAND_NORMAL);
- type = TREE_TYPE (exp);
-
- /* If all we do is reference a volatile value in memory,
- copy it to a register to be sure it is actually touched. */
- if (value && MEM_P (value) && TREE_THIS_VOLATILE (exp))
- {
- if (TYPE_MODE (type) == VOIDmode)
- ;
- else if (TYPE_MODE (type) != BLKmode)
- copy_to_reg (value);
- else
- {
- rtx lab = gen_label_rtx ();
-
- /* Compare the value with itself to reference it. */
- emit_cmp_and_jump_insns (value, value, EQ,
- expand_normal (TYPE_SIZE (type)),
- BLKmode, 0, lab);
- emit_label (lab);
- }
- }
-
- /* Free any temporaries used to evaluate this expression. */
- free_temp_slots ();
-}
-
-\f
-/* Generate RTL to return from the current function, with no value.
- (That is, we do not do anything about returning any value.) */
-
-void
-expand_null_return (void)
-{
- /* If this function was declared to return a value, but we
- didn't, clobber the return registers so that they are not
- propagated live to the rest of the function. */
- clobber_return_register ();
-
- expand_null_return_1 ();
-}
/* Generate RTL to return directly from the current function.
(That is, we bypass any return value.) */
void
expand_naked_return (void)
{
- rtx end_label;
+ rtx_code_label *end_label;
clear_pending_stack_adjust ();
do_pending_stack_adjust ();
emit_jump (end_label);
}
-/* Generate RTL to return from the current function, with value VAL. */
-
+/* Generate code to jump to LABEL if OP0 and OP1 are equal in mode MODE. PROB
+ is the probability of jumping to LABEL. */
static void
-expand_value_return (rtx val)
+do_jump_if_equal (machine_mode mode, rtx op0, rtx op1, rtx_code_label *label,
+ int unsignedp, profile_probability prob)
{
- /* Copy the value to the return location unless it's already there. */
-
- tree decl = DECL_RESULT (current_function_decl);
- rtx return_reg = DECL_RTL (decl);
- if (return_reg != val)
- {
- tree funtype = TREE_TYPE (current_function_decl);
- tree type = TREE_TYPE (decl);
- int unsignedp = TYPE_UNSIGNED (type);
- enum machine_mode old_mode = DECL_MODE (decl);
- enum machine_mode mode;
- if (DECL_BY_REFERENCE (decl))
- mode = promote_function_mode (type, old_mode, &unsignedp, funtype, 2);
- else
- mode = promote_function_mode (type, old_mode, &unsignedp, funtype, 1);
-
- if (mode != old_mode)
- val = convert_modes (mode, old_mode, val, unsignedp);
-
- if (GET_CODE (return_reg) == PARALLEL)
- emit_group_load (return_reg, val, type, int_size_in_bytes (type));
- else
- emit_move_insn (return_reg, val);
- }
-
- expand_null_return_1 ();
+ do_compare_rtx_and_jump (op0, op1, EQ, unsignedp, mode,
+ NULL_RTX, NULL, label, prob);
}
+\f
+/* Return the sum of probabilities of outgoing edges of basic block BB. */
-/* Output a return with no value. */
-
-static void
-expand_null_return_1 (void)
+static profile_probability
+get_outgoing_edge_probs (basic_block bb)
{
- clear_pending_stack_adjust ();
- do_pending_stack_adjust ();
- emit_jump (return_label);
+ edge e;
+ edge_iterator ei;
+ profile_probability prob_sum = profile_probability::never ();
+ if (!bb)
+ return profile_probability::never ();
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ prob_sum += e->probability;
+ return prob_sum;
}
-\f
-/* Generate RTL to evaluate the expression RETVAL and return it
- from the current function. */
-void
-expand_return (tree retval)
-{
- rtx result_rtl;
- rtx val = 0;
- tree retval_rhs;
+/* Computes the conditional probability of jumping to a target if the branch
+ instruction is executed.
+ TARGET_PROB is the estimated probability of jumping to a target relative
+ to some basic block BB.
+ BASE_PROB is the probability of reaching the branch instruction relative
+ to the same basic block BB. */
- /* If function wants no value, give it none. */
- if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE)
- {
- expand_normal (retval);
- expand_null_return ();
- return;
- }
+static inline profile_probability
+conditional_probability (profile_probability target_prob,
+ profile_probability base_prob)
+{
+ return target_prob / base_prob;
+}
- if (retval == error_mark_node)
- {
- /* Treat this like a return of no value from a function that
- returns a value. */
- expand_null_return ();
- return;
- }
- else if ((TREE_CODE (retval) == MODIFY_EXPR
- || TREE_CODE (retval) == INIT_EXPR)
- && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL)
- retval_rhs = TREE_OPERAND (retval, 1);
- else
- retval_rhs = retval;
+/* Generate a dispatch tabler, switching on INDEX_EXPR and jumping to
+ one of the labels in CASE_LIST or to the DEFAULT_LABEL.
+ MINVAL, MAXVAL, and RANGE are the extrema and range of the case
+ labels in CASE_LIST. STMT_BB is the basic block containing the statement.
- result_rtl = DECL_RTL (DECL_RESULT (current_function_decl));
+ First, a jump insn is emitted. First we try "casesi". If that
+ fails, try "tablejump". A target *must* have one of them (or both).
- /* If we are returning the RESULT_DECL, then the value has already
- been stored into it, so we don't have to do anything special. */
- if (TREE_CODE (retval_rhs) == RESULT_DECL)
- expand_value_return (result_rtl);
+ Then, a table with the target labels is emitted.
- /* If the result is an aggregate that is being returned in one (or more)
- registers, load the registers here. */
+ The process is unaware of the CFG. The caller has to fix up
+ the CFG itself. This is done in cfgexpand.c. */
- else if (retval_rhs != 0
- && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode
- && REG_P (result_rtl))
- {
- val = copy_blkmode_to_reg (GET_MODE (result_rtl), retval_rhs);
- if (val)
- {
- /* Use the mode of the result value on the return register. */
- PUT_MODE (result_rtl, GET_MODE (val));
- expand_value_return (val);
- }
- else
- expand_null_return ();
- }
- else if (retval_rhs != 0
- && !VOID_TYPE_P (TREE_TYPE (retval_rhs))
- && (REG_P (result_rtl)
- || (GET_CODE (result_rtl) == PARALLEL)))
- {
- /* Calculate the return value into a temporary (usually a pseudo
- reg). */
- tree ot = TREE_TYPE (DECL_RESULT (current_function_decl));
- tree nt = build_qualified_type (ot, TYPE_QUALS (ot) | TYPE_QUAL_CONST);
-
- val = assign_temp (nt, 0, 1);
- val = expand_expr (retval_rhs, val, GET_MODE (val), EXPAND_NORMAL);
- val = force_not_mem (val);
- /* Return the calculated value. */
- expand_value_return (val);
- }
- else
- {
- /* No hard reg used; calculate value into hard return reg. */
- expand_expr (retval, const0_rtx, VOIDmode, EXPAND_NORMAL);
- expand_value_return (result_rtl);
- }
-}
-\f
-/* Emit code to restore vital registers at the beginning of a nonlocal goto
- handler. */
static void
-expand_nl_goto_receiver (void)
+emit_case_dispatch_table (tree index_expr, tree index_type,
+ auto_vec<simple_case_node> &case_list,
+ rtx default_label,
+ edge default_edge, tree minval, tree maxval,
+ tree range, basic_block stmt_bb)
{
- rtx chain;
-
- /* Clobber the FP when we get here, so we have to make sure it's
- marked as used by this function. */
- emit_use (hard_frame_pointer_rtx);
-
- /* Mark the static chain as clobbered here so life information
- doesn't get messed up for it. */
- chain = targetm.calls.static_chain (current_function_decl, true);
- if (chain && REG_P (chain))
- emit_clobber (chain);
-
-#ifdef HAVE_nonlocal_goto
- if (! HAVE_nonlocal_goto)
-#endif
- /* First adjust our frame pointer to its actual value. It was
- previously set to the start of the virtual area corresponding to
- the stacked variables when we branched here and now needs to be
- adjusted to the actual hardware fp value.
-
- Assignments are to virtual registers are converted by
- instantiate_virtual_regs into the corresponding assignment
- to the underlying register (fp in this case) that makes
- the original assignment true.
- So the following insn will actually be
- decrementing fp by STARTING_FRAME_OFFSET. */
- emit_move_insn (virtual_stack_vars_rtx, hard_frame_pointer_rtx);
-
-#if !HARD_FRAME_POINTER_IS_ARG_POINTER
- if (fixed_regs[ARG_POINTER_REGNUM])
+ int i, ncases;
+ rtx *labelvec;
+ rtx_insn *fallback_label = label_rtx (case_list[0].m_code_label);
+ rtx_code_label *table_label = gen_label_rtx ();
+ bool has_gaps = false;
+ profile_probability default_prob = default_edge ? default_edge->probability
+ : profile_probability::never ();
+ profile_probability base = get_outgoing_edge_probs (stmt_bb);
+ bool try_with_tablejump = false;
+
+ profile_probability new_default_prob = conditional_probability (default_prob,
+ base);
+
+ if (! try_casesi (index_type, index_expr, minval, range,
+ table_label, default_label, fallback_label,
+ new_default_prob))
{
-#ifdef ELIMINABLE_REGS
- /* If the argument pointer can be eliminated in favor of the
- frame pointer, we don't need to restore it. We assume here
- that if such an elimination is present, it can always be used.
- This is the case on all known machines; if we don't make this
- assumption, we do unnecessary saving on many machines. */
- static const struct elims {const int from, to;} elim_regs[] = ELIMINABLE_REGS;
- size_t i;
-
- for (i = 0; i < ARRAY_SIZE (elim_regs); i++)
- if (elim_regs[i].from == ARG_POINTER_REGNUM
- && elim_regs[i].to == HARD_FRAME_POINTER_REGNUM)
- break;
-
- if (i == ARRAY_SIZE (elim_regs))
-#endif
+ /* Index jumptables from zero for suitable values of minval to avoid
+ a subtraction. For the rationale see:
+ "http://gcc.gnu.org/ml/gcc-patches/2001-10/msg01234.html". */
+ if (optimize_insn_for_speed_p ()
+ && compare_tree_int (minval, 0) > 0
+ && compare_tree_int (minval, 3) < 0)
{
- /* Now restore our arg pointer from the address at which it
- was saved in our stack frame. */
- emit_move_insn (crtl->args.internal_arg_pointer,
- copy_to_reg (get_arg_pointer_save_area ()));
+ minval = build_int_cst (index_type, 0);
+ range = maxval;
+ has_gaps = true;
}
+ try_with_tablejump = true;
}
-#endif
-
-#ifdef HAVE_nonlocal_goto_receiver
- if (HAVE_nonlocal_goto_receiver)
- emit_insn (gen_nonlocal_goto_receiver ());
-#endif
- /* We must not allow the code we just generated to be reordered by
- scheduling. Specifically, the update of the frame pointer must
- happen immediately, not later. */
- emit_insn (gen_blockage ());
-}
-\f
-/* Emit code to save the current value of stack. */
-rtx
-expand_stack_save (void)
-{
- rtx ret = NULL_RTX;
+ /* Get table of labels to jump to, in order of case index. */
- do_pending_stack_adjust ();
- emit_stack_save (SAVE_BLOCK, &ret);
- return ret;
-}
+ ncases = tree_to_shwi (range) + 1;
+ labelvec = XALLOCAVEC (rtx, ncases);
+ memset (labelvec, 0, ncases * sizeof (rtx));
-/* Emit code to restore the current value of stack. */
-void
-expand_stack_restore (tree var)
-{
- rtx prev, sa = expand_normal (var);
+ for (unsigned j = 0; j < case_list.length (); j++)
+ {
+ simple_case_node *n = &case_list[j];
+ /* Compute the low and high bounds relative to the minimum
+ value since that should fit in a HOST_WIDE_INT while the
+ actual values may not. */
+ HOST_WIDE_INT i_low
+ = tree_to_uhwi (fold_build2 (MINUS_EXPR, index_type,
+ n->m_low, minval));
+ HOST_WIDE_INT i_high
+ = tree_to_uhwi (fold_build2 (MINUS_EXPR, index_type,
+ n->m_high, minval));
+ HOST_WIDE_INT i;
+
+ for (i = i_low; i <= i_high; i ++)
+ labelvec[i]
+ = gen_rtx_LABEL_REF (Pmode, label_rtx (n->m_code_label));
+ }
- sa = convert_memory_address (Pmode, sa);
+ /* The dispatch table may contain gaps, including at the beginning of
+ the table if we tried to avoid the minval subtraction. We fill the
+ dispatch table slots associated with the gaps with the default case label.
+ However, in the event the default case is unreachable, we then use
+ any label from one of the case statements. */
+ rtx gap_label = (default_label) ? default_label : fallback_label;
- prev = get_last_insn ();
- emit_stack_restore (SAVE_BLOCK, sa);
- fixup_args_size_notes (prev, get_last_insn (), 0);
-}
-\f
-/* Do the insertion of a case label into case_list. The labels are
- fed to us in descending order from the sorted vector of case labels used
- in the tree part of the middle end. So the list we construct is
- sorted in ascending order. The bounds on the case range, LOW and HIGH,
- are converted to case's index type TYPE. Note that the original type
- of the case index in the source code is usually "lost" during
- gimplification due to type promotion, but the case labels retain the
- original type. */
-
-static struct case_node *
-add_case_node (struct case_node *head, tree type, tree low, tree high,
- tree label, alloc_pool case_node_pool)
-{
- struct case_node *r;
-
- gcc_checking_assert (low);
- gcc_checking_assert (! high || (TREE_TYPE (low) == TREE_TYPE (high)));
-
- /* Add this label to the chain. Make sure to drop overflow flags. */
- r = (struct case_node *) pool_alloc (case_node_pool);
- r->low = build_int_cst_wide (type, TREE_INT_CST_LOW (low),
- TREE_INT_CST_HIGH (low));
- r->high = build_int_cst_wide (type, TREE_INT_CST_LOW (high),
- TREE_INT_CST_HIGH (high));
- r->code_label = label;
- r->parent = r->left = NULL;
- r->right = head;
- return r;
-}
-\f
-#ifndef HAVE_casesi
-#define HAVE_casesi 0
-#endif
+ for (i = 0; i < ncases; i++)
+ if (labelvec[i] == 0)
+ {
+ has_gaps = true;
+ labelvec[i] = gen_rtx_LABEL_REF (Pmode, gap_label);
+ }
-#ifndef HAVE_tablejump
-#define HAVE_tablejump 0
-#endif
+ if (has_gaps && default_label)
+ {
+ /* There is at least one entry in the jump table that jumps
+ to default label. The default label can either be reached
+ through the indirect jump or the direct conditional jump
+ before that. Split the probability of reaching the
+ default label among these two jumps. */
+ new_default_prob
+ = conditional_probability (default_prob.apply_scale (1, 2), base);
+ default_prob = default_prob.apply_scale (1, 2);
+ base -= default_prob;
+ }
+ else
+ {
+ base -= default_prob;
+ default_prob = profile_probability::never ();
+ }
-/* Return the smallest number of different values for which it is best to use a
- jump-table instead of a tree of conditional branches. */
+ if (default_edge)
+ default_edge->probability = default_prob;
-static unsigned int
-case_values_threshold (void)
-{
- unsigned int threshold = PARAM_VALUE (PARAM_CASE_VALUES_THRESHOLD);
+ /* We have altered the probability of the default edge. So the probabilities
+ of all other edges need to be adjusted so that it sums up to
+ REG_BR_PROB_BASE. */
+ if (base > profile_probability::never ())
+ {
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, stmt_bb->succs)
+ e->probability /= base;
+ }
- if (threshold == 0)
- threshold = targetm.case_values_threshold ();
+ if (try_with_tablejump)
+ {
+ bool ok = try_tablejump (index_type, index_expr, minval, range,
+ table_label, default_label, new_default_prob);
+ gcc_assert (ok);
+ }
+ /* Output the table. */
+ emit_label (table_label);
+
+ if (CASE_VECTOR_PC_RELATIVE
+ || (flag_pic && targetm.asm_out.generate_pic_addr_diff_vec ()))
+ emit_jump_table_data (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
+ gen_rtx_LABEL_REF (Pmode,
+ table_label),
+ gen_rtvec_v (ncases, labelvec),
+ const0_rtx, const0_rtx));
+ else
+ emit_jump_table_data (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
+ gen_rtvec_v (ncases, labelvec)));
- return threshold;
+ /* Record no drop-through after the table. */
+ emit_barrier ();
}
-/* Terminate a case (Pascal/Ada) or switch (C) statement
+/* Terminate a case Ada or switch (C) statement
in which ORIG_INDEX is the expression to be tested.
If ORIG_TYPE is not NULL, it is the original ORIG_INDEX
type as given in the source before any compiler conversions.
Generate the code to test it and jump to the right place. */
void
-expand_case (gimple stmt)
+expand_case (gswitch *stmt)
{
tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE;
- rtx default_label = 0;
- struct case_node *n;
- unsigned int count, uniq;
- rtx index;
- rtx table_label;
- int ncases;
- rtx *labelvec;
+ rtx_code_label *default_label;
+ unsigned int count;
int i;
- rtx before_case, end, lab;
-
+ int ncases = gimple_switch_num_labels (stmt);
tree index_expr = gimple_switch_index (stmt);
tree index_type = TREE_TYPE (index_expr);
- int unsignedp = TYPE_UNSIGNED (index_type);
+ tree elt;
+ basic_block bb = gimple_bb (stmt);
+ gimple *def_stmt;
- /* The insn after which the case dispatch should finally
- be emitted. Zero for a dummy. */
- rtx start;
+ auto_vec<simple_case_node> case_list;
- /* A list of case labels; it is first built as a list and it may then
- be rearranged into a nearly balanced binary tree. */
- struct case_node *case_list = 0;
+ /* An ERROR_MARK occurs for various reasons including invalid data type.
+ ??? Can this still happen, with GIMPLE and all? */
+ if (index_type == error_mark_node)
+ return;
- /* Label to jump to if no case matches. */
- tree default_label_decl = NULL_TREE;
+ /* cleanup_tree_cfg removes all SWITCH_EXPR with their index
+ expressions being INTEGER_CST. */
+ gcc_assert (TREE_CODE (index_expr) != INTEGER_CST);
- alloc_pool case_node_pool = create_alloc_pool ("struct case_node pool",
- sizeof (struct case_node),
- 100);
+ /* Optimization of switch statements with only one label has already
+ occurred, so we should never see them at this point. */
+ gcc_assert (ncases > 1);
do_pending_stack_adjust ();
- /* An ERROR_MARK occurs for various reasons including invalid data type. */
- if (index_type != error_mark_node)
+ /* Find the default case target label. */
+ tree default_lab = CASE_LABEL (gimple_switch_default_label (stmt));
+ default_label = jump_target_rtx (default_lab);
+ basic_block default_bb = label_to_block (cfun, default_lab);
+ edge default_edge = find_edge (bb, default_bb);
+
+ /* Get upper and lower bounds of case values. */
+ elt = gimple_switch_label (stmt, 1);
+ minval = fold_convert (index_type, CASE_LOW (elt));
+ elt = gimple_switch_label (stmt, ncases - 1);
+ if (CASE_HIGH (elt))
+ maxval = fold_convert (index_type, CASE_HIGH (elt));
+ else
+ maxval = fold_convert (index_type, CASE_LOW (elt));
+
+ /* Try to narrow the index type if it's larger than a word.
+ That is mainly for -O0 where an equivalent optimization
+ done by forward propagation is not run and is aimed at
+ avoiding a call to a comparison routine of libgcc. */
+ if (TYPE_PRECISION (index_type) > BITS_PER_WORD
+ && TREE_CODE (index_expr) == SSA_NAME
+ && (def_stmt = SSA_NAME_DEF_STMT (index_expr))
+ && is_gimple_assign (def_stmt)
+ && gimple_assign_rhs_code (def_stmt) == NOP_EXPR)
{
- tree elt;
- bitmap label_bitmap;
- int stopi = 0;
-
- /* cleanup_tree_cfg removes all SWITCH_EXPR with their index
- expressions being INTEGER_CST. */
- gcc_assert (TREE_CODE (index_expr) != INTEGER_CST);
-
- /* The default case, if ever taken, is the first element. */
- elt = gimple_switch_label (stmt, 0);
- if (!CASE_LOW (elt) && !CASE_HIGH (elt))
- {
- default_label_decl = CASE_LABEL (elt);
- stopi = 1;
- }
+ tree inner_index_expr = gimple_assign_rhs1 (def_stmt);
+ tree inner_index_type = TREE_TYPE (inner_index_expr);
- for (i = gimple_switch_num_labels (stmt) - 1; i >= stopi; --i)
+ if (INTEGRAL_TYPE_P (inner_index_type)
+ && TYPE_PRECISION (inner_index_type) <= BITS_PER_WORD
+ && int_fits_type_p (minval, inner_index_type)
+ && int_fits_type_p (maxval, inner_index_type))
{
- tree low, high;
- elt = gimple_switch_label (stmt, i);
-
- low = CASE_LOW (elt);
- gcc_assert (low);
- high = CASE_HIGH (elt);
-
- /* The canonical from of a case label in GIMPLE is that a simple case
- has an empty CASE_HIGH. For the casesi and tablejump expanders,
- the back ends want simple cases to have high == low. */
- gcc_assert (! high || tree_int_cst_lt (low, high));
- if (! high)
- high = low;
-
- case_list = add_case_node (case_list, index_type, low, high,
- CASE_LABEL (elt), case_node_pool);
+ index_expr = inner_index_expr;
+ index_type = inner_index_type;
+ minval = fold_convert (index_type, minval);
+ maxval = fold_convert (index_type, maxval);
}
-
-
- before_case = start = get_last_insn ();
- if (default_label_decl)
- default_label = label_rtx (default_label_decl);
-
- /* Get upper and lower bounds of case values. */
-
- uniq = 0;
- count = 0;
- label_bitmap = BITMAP_ALLOC (NULL);
- for (n = case_list; n; n = n->right)
- {
- /* Count the elements and track the largest and smallest
- of them (treating them as signed even if they are not). */
- if (count++ == 0)
- {
- minval = n->low;
- maxval = n->high;
- }
- else
- {
- if (tree_int_cst_lt (n->low, minval))
- minval = n->low;
- if (tree_int_cst_lt (maxval, n->high))
- maxval = n->high;
- }
- /* A range counts double, since it requires two compares. */
- if (! tree_int_cst_equal (n->low, n->high))
- count++;
-
- /* If we have not seen this label yet, then increase the
- number of unique case node targets seen. */
- lab = label_rtx (n->code_label);
- if (bitmap_set_bit (label_bitmap, CODE_LABEL_NUMBER (lab)))
- uniq++;
- }
-
- BITMAP_FREE (label_bitmap);
-
- /* cleanup_tree_cfg removes all SWITCH_EXPR with a single
- destination, such as one with a default case only.
- It also removes cases that are out of range for the switch
- type, so we should never get a zero here. */
- gcc_assert (count > 0);
-
- /* Compute span of values. */
- range = fold_build2 (MINUS_EXPR, index_type, maxval, minval);
-
- /* If range of values is much bigger than number of values,
- make a sequence of conditional branches instead of a dispatch.
- If the switch-index is a constant, do it this way
- because we can optimize it. */
-
- if (count < case_values_threshold ()
- || compare_tree_int (range,
- (optimize_insn_for_size_p () ? 3 : 10) * count) > 0
- /* RANGE may be signed, and really large ranges will show up
- as negative numbers. */
- || compare_tree_int (range, 0) < 0
- || !flag_jump_tables
- || TREE_CONSTANT (index_expr)
- /* If neither casesi or tablejump is available, we can
- only go this way. */
- || (!HAVE_casesi && !HAVE_tablejump))
- {
- index = expand_normal (index_expr);
-
- /* If the index is a short or char that we do not have
- an insn to handle comparisons directly, convert it to
- a full integer now, rather than letting each comparison
- generate the conversion. */
-
- if (GET_MODE_CLASS (GET_MODE (index)) == MODE_INT
- && ! have_insn_for (COMPARE, GET_MODE (index)))
- {
- enum machine_mode wider_mode;
- for (wider_mode = GET_MODE (index); wider_mode != VOIDmode;
- wider_mode = GET_MODE_WIDER_MODE (wider_mode))
- if (have_insn_for (COMPARE, wider_mode))
- {
- index = convert_to_mode (wider_mode, index, unsignedp);
- break;
- }
- }
-
- do_pending_stack_adjust ();
-
- if (MEM_P (index))
- {
- index = copy_to_reg (index);
- if (TREE_CODE (index_expr) == SSA_NAME)
- set_reg_attrs_for_decl_rtl (SSA_NAME_VAR (index_expr), index);
- }
-
- /* We generate a binary decision tree to select the
- appropriate target code. This is done as follows:
-
- The list of cases is rearranged into a binary tree,
- nearly optimal assuming equal probability for each case.
-
- The tree is transformed into RTL, eliminating
- redundant test conditions at the same time.
-
- If program flow could reach the end of the
- decision tree an unconditional jump to the
- default code is emitted. */
-
- balance_case_nodes (&case_list, NULL);
- emit_case_nodes (index, case_list, default_label, index_type);
- if (default_label)
- emit_jump (default_label);
- }
- else
- {
- rtx fallback_label = label_rtx (case_list->code_label);
- table_label = gen_label_rtx ();
- if (! try_casesi (index_type, index_expr, minval, range,
- table_label, default_label, fallback_label))
- {
- bool ok;
-
- /* Index jumptables from zero for suitable values of
- minval to avoid a subtraction. */
- if (optimize_insn_for_speed_p ()
- && compare_tree_int (minval, 0) > 0
- && compare_tree_int (minval, 3) < 0)
- {
- minval = build_int_cst (index_type, 0);
- range = maxval;
- }
-
- ok = try_tablejump (index_type, index_expr, minval, range,
- table_label, default_label);
- gcc_assert (ok);
- }
-
- /* Get table of labels to jump to, in order of case index. */
-
- ncases = tree_low_cst (range, 0) + 1;
- labelvec = XALLOCAVEC (rtx, ncases);
- memset (labelvec, 0, ncases * sizeof (rtx));
-
- for (n = case_list; n; n = n->right)
- {
- /* Compute the low and high bounds relative to the minimum
- value since that should fit in a HOST_WIDE_INT while the
- actual values may not. */
- HOST_WIDE_INT i_low
- = tree_low_cst (fold_build2 (MINUS_EXPR, index_type,
- n->low, minval), 1);
- HOST_WIDE_INT i_high
- = tree_low_cst (fold_build2 (MINUS_EXPR, index_type,
- n->high, minval), 1);
- HOST_WIDE_INT i;
-
- for (i = i_low; i <= i_high; i ++)
- labelvec[i]
- = gen_rtx_LABEL_REF (Pmode, label_rtx (n->code_label));
- }
-
- /* Fill in the gaps with the default. We may have gaps at
- the beginning if we tried to avoid the minval subtraction,
- so substitute some label even if the default label was
- deemed unreachable. */
- if (!default_label)
- default_label = fallback_label;
- for (i = 0; i < ncases; i++)
- if (labelvec[i] == 0)
- labelvec[i] = gen_rtx_LABEL_REF (Pmode, default_label);
-
- /* Output the table. */
- emit_label (table_label);
-
- if (CASE_VECTOR_PC_RELATIVE || flag_pic)
- emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE,
- gen_rtx_LABEL_REF (Pmode, table_label),
- gen_rtvec_v (ncases, labelvec),
- const0_rtx, const0_rtx));
- else
- emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE,
- gen_rtvec_v (ncases, labelvec)));
-
- /* Record no drop-through after the table. */
- emit_barrier ();
- }
-
- before_case = NEXT_INSN (before_case);
- end = get_last_insn ();
- reorder_insns (before_case, end, start);
}
- free_temp_slots ();
- free_alloc_pool (case_node_pool);
-}
+ /* Compute span of values. */
+ range = fold_build2 (MINUS_EXPR, index_type, maxval, minval);
-/* Generate code to jump to LABEL if OP0 and OP1 are equal in mode MODE. */
+ /* Listify the labels queue and gather some numbers to decide
+ how to expand this switch(). */
+ count = 0;
-static void
-do_jump_if_equal (enum machine_mode mode, rtx op0, rtx op1, rtx label,
- int unsignedp)
-{
- do_compare_rtx_and_jump (op0, op1, EQ, unsignedp, mode,
- NULL_RTX, NULL_RTX, label, -1);
-}
-\f
-/* Take an ordered list of case nodes
- and transform them into a near optimal binary tree,
- on the assumption that any target code selection value is as
- likely as any other.
-
- The transformation is performed by splitting the ordered
- list into two equal sections plus a pivot. The parts are
- then attached to the pivot as left and right branches. Each
- branch is then transformed recursively. */
-
-static void
-balance_case_nodes (case_node_ptr *head, case_node_ptr parent)
-{
- case_node_ptr np;
-
- np = *head;
- if (np)
+ for (i = ncases - 1; i >= 1; --i)
{
- int i = 0;
- int ranges = 0;
- case_node_ptr *npp;
- case_node_ptr left;
-
- /* Count the number of entries on branch. Also count the ranges. */
-
- while (np)
- {
- if (!tree_int_cst_equal (np->low, np->high))
- ranges++;
-
- i++;
- np = np->right;
- }
-
- if (i > 2)
- {
- /* Split this list if it is long enough for that to help. */
- npp = head;
- left = *npp;
-
- /* If there are just three nodes, split at the middle one. */
- if (i == 3)
- npp = &(*npp)->right;
- else
- {
- /* Find the place in the list that bisects the list's total cost,
- where ranges count as 2.
- Here I gets half the total cost. */
- i = (i + ranges + 1) / 2;
- while (1)
- {
- /* Skip nodes while their cost does not reach that amount. */
- if (!tree_int_cst_equal ((*npp)->low, (*npp)->high))
- i--;
- i--;
- if (i <= 0)
- break;
- npp = &(*npp)->right;
- }
- }
- *head = np = *npp;
- *npp = 0;
- np->parent = parent;
- np->left = left;
-
- /* Optimize each of the two split parts. */
- balance_case_nodes (&np->left, np);
- balance_case_nodes (&np->right, np);
- }
- else
- {
- /* Else leave this branch as one level,
- but fill in `parent' fields. */
- np = *head;
- np->parent = parent;
- for (; np->right; np = np->right)
- np->right->parent = np;
- }
+ elt = gimple_switch_label (stmt, i);
+ tree low = CASE_LOW (elt);
+ gcc_assert (low);
+ tree high = CASE_HIGH (elt);
+ gcc_assert (! high || tree_int_cst_lt (low, high));
+ tree lab = CASE_LABEL (elt);
+
+ /* Count the elements.
+ A range counts double, since it requires two compares. */
+ count++;
+ if (high)
+ count++;
+
+ /* The bounds on the case range, LOW and HIGH, have to be converted
+ to case's index type TYPE. Note that the original type of the
+ case index in the source code is usually "lost" during
+ gimplification due to type promotion, but the case labels retain the
+ original type. Make sure to drop overflow flags. */
+ low = fold_convert (index_type, low);
+ if (TREE_OVERFLOW (low))
+ low = wide_int_to_tree (index_type, wi::to_wide (low));
+
+ /* The canonical from of a case label in GIMPLE is that a simple case
+ has an empty CASE_HIGH. For the casesi and tablejump expanders,
+ the back ends want simple cases to have high == low. */
+ if (! high)
+ high = low;
+ high = fold_convert (index_type, high);
+ if (TREE_OVERFLOW (high))
+ high = wide_int_to_tree (index_type, wi::to_wide (high));
+
+ case_list.safe_push (simple_case_node (low, high, lab));
}
-}
-\f
-/* Search the parent sections of the case node tree
- to see if a test for the lower bound of NODE would be redundant.
- INDEX_TYPE is the type of the index expression.
-
- The instructions to generate the case decision tree are
- output in the same order as nodes are processed so it is
- known that if a parent node checks the range of the current
- node minus one that the current node is bounded at its lower
- span. Thus the test would be redundant. */
-
-static int
-node_has_low_bound (case_node_ptr node, tree index_type)
-{
- tree low_minus_one;
- case_node_ptr pnode;
- /* If the lower bound of this node is the lowest value in the index type,
- we need not test it. */
+ /* cleanup_tree_cfg removes all SWITCH_EXPR with a single
+ destination, such as one with a default case only.
+ It also removes cases that are out of range for the switch
+ type, so we should never get a zero here. */
+ gcc_assert (count > 0);
- if (tree_int_cst_equal (node->low, TYPE_MIN_VALUE (index_type)))
- return 1;
+ rtx_insn *before_case = get_last_insn ();
- /* If this node has a left branch, the value at the left must be less
- than that at this node, so it cannot be bounded at the bottom and
- we need not bother testing any further. */
-
- if (node->left)
- return 0;
-
- low_minus_one = fold_build2 (MINUS_EXPR, TREE_TYPE (node->low),
- node->low,
- build_int_cst (TREE_TYPE (node->low), 1));
-
- /* If the subtraction above overflowed, we can't verify anything.
- Otherwise, look for a parent that tests our value - 1. */
-
- if (! tree_int_cst_lt (low_minus_one, node->low))
- return 0;
-
- for (pnode = node->parent; pnode; pnode = pnode->parent)
- if (tree_int_cst_equal (low_minus_one, pnode->high))
- return 1;
-
- return 0;
-}
-
-/* Search the parent sections of the case node tree
- to see if a test for the upper bound of NODE would be redundant.
- INDEX_TYPE is the type of the index expression.
-
- The instructions to generate the case decision tree are
- output in the same order as nodes are processed so it is
- known that if a parent node checks the range of the current
- node plus one that the current node is bounded at its upper
- span. Thus the test would be redundant. */
-
-static int
-node_has_high_bound (case_node_ptr node, tree index_type)
-{
- tree high_plus_one;
- case_node_ptr pnode;
-
- /* If there is no upper bound, obviously no test is needed. */
-
- if (TYPE_MAX_VALUE (index_type) == NULL)
- return 1;
-
- /* If the upper bound of this node is the highest value in the type
- of the index expression, we need not test against it. */
-
- if (tree_int_cst_equal (node->high, TYPE_MAX_VALUE (index_type)))
- return 1;
-
- /* If this node has a right branch, the value at the right must be greater
- than that at this node, so it cannot be bounded at the top and
- we need not bother testing any further. */
-
- if (node->right)
- return 0;
-
- high_plus_one = fold_build2 (PLUS_EXPR, TREE_TYPE (node->high),
- node->high,
- build_int_cst (TREE_TYPE (node->high), 1));
-
- /* If the addition above overflowed, we can't verify anything.
- Otherwise, look for a parent that tests our value + 1. */
+ /* If the default case is unreachable, then set default_label to NULL
+ so that we omit the range check when generating the dispatch table.
+ We also remove the edge to the unreachable default case. The block
+ itself will be automatically removed later. */
+ if (EDGE_COUNT (default_edge->dest->succs) == 0
+ && gimple_seq_unreachable_p (bb_seq (default_edge->dest)))
+ {
+ default_label = NULL;
+ remove_edge (default_edge);
+ default_edge = NULL;
+ }
- if (! tree_int_cst_lt (node->high, high_plus_one))
- return 0;
+ emit_case_dispatch_table (index_expr, index_type,
+ case_list, default_label, default_edge,
+ minval, maxval, range, bb);
- for (pnode = node->parent; pnode; pnode = pnode->parent)
- if (tree_int_cst_equal (high_plus_one, pnode->low))
- return 1;
+ reorder_insns (NEXT_INSN (before_case), get_last_insn (), before_case);
- return 0;
+ free_temp_slots ();
}
-/* Search the parent sections of the
- case node tree to see if both tests for the upper and lower
- bounds of NODE would be redundant. */
+/* Expand the dispatch to a short decrement chain if there are few cases
+ to dispatch to. Likewise if neither casesi nor tablejump is available,
+ or if flag_jump_tables is set. Otherwise, expand as a casesi or a
+ tablejump. The index mode is always the mode of integer_type_node.
+ Trap if no case matches the index.
-static int
-node_is_bounded (case_node_ptr node, tree index_type)
-{
- return (node_has_low_bound (node, index_type)
- && node_has_high_bound (node, index_type));
-}
-\f
-/* Emit step-by-step code to select a case for the value of INDEX.
- The thus generated decision tree follows the form of the
- case-node binary tree NODE, whose nodes represent test conditions.
- INDEX_TYPE is the type of the index of the switch.
-
- Care is taken to prune redundant tests from the decision tree
- by detecting any boundary conditions already checked by
- emitted rtx. (See node_has_high_bound, node_has_low_bound
- and node_is_bounded, above.)
-
- Where the test conditions can be shown to be redundant we emit
- an unconditional jump to the target code. As a further
- optimization, the subordinates of a tree node are examined to
- check for bounded nodes. In this case conditional and/or
- unconditional jumps as a result of the boundary check for the
- current node are arranged to target the subordinates associated
- code for out of bound conditions on the current node.
-
- We can assume that when control reaches the code generated here,
- the index value has already been compared with the parents
- of this node, and determined to be on the same side of each parent
- as this node is. Thus, if this node tests for the value 51,
- and a parent tested for 52, we don't need to consider
- the possibility of a value greater than 51. If another parent
- tests for the value 50, then this node need not test anything. */
+ DISPATCH_INDEX is the index expression to switch on. It should be a
+ memory or register operand.
+
+ DISPATCH_TABLE is a set of case labels. The set should be sorted in
+ ascending order, be contiguous, starting with value 0, and contain only
+ single-valued case labels. */
-static void
-emit_case_nodes (rtx index, case_node_ptr node, rtx default_label,
- tree index_type)
+void
+expand_sjlj_dispatch_table (rtx dispatch_index,
+ vec<tree> dispatch_table)
{
- /* If INDEX has an unsigned type, we must make unsigned branches. */
- int unsignedp = TYPE_UNSIGNED (index_type);
- enum machine_mode mode = GET_MODE (index);
- enum machine_mode imode = TYPE_MODE (index_type);
-
- /* Handle indices detected as constant during RTL expansion. */
- if (mode == VOIDmode)
- mode = imode;
+ tree index_type = integer_type_node;
+ machine_mode index_mode = TYPE_MODE (index_type);
- /* See if our parents have already tested everything for us.
- If they have, emit an unconditional jump for this node. */
- if (node_is_bounded (node, index_type))
- emit_jump (label_rtx (node->code_label));
+ int ncases = dispatch_table.length ();
- else if (tree_int_cst_equal (node->low, node->high))
+ do_pending_stack_adjust ();
+ rtx_insn *before_case = get_last_insn ();
+
+ /* Expand as a decrement-chain if there are 5 or fewer dispatch
+ labels. This covers more than 98% of the cases in libjava,
+ and seems to be a reasonable compromise between the "old way"
+ of expanding as a decision tree or dispatch table vs. the "new
+ way" with decrement chain or dispatch table. */
+ if (dispatch_table.length () <= 5
+ || (!targetm.have_casesi () && !targetm.have_tablejump ())
+ || !flag_jump_tables)
{
- /* Node is single valued. First see if the index expression matches
- this node and then check our children, if any. */
-
- do_jump_if_equal (mode, index,
- convert_modes (mode, imode,
- expand_normal (node->low),
- unsignedp),
- label_rtx (node->code_label), unsignedp);
-
- if (node->right != 0 && node->left != 0)
- {
- /* This node has children on both sides.
- Dispatch to one side or the other
- by comparing the index value with this node's value.
- If one subtree is bounded, check that one first,
- so we can avoid real branches in the tree. */
-
- if (node_is_bounded (node->right, index_type))
- {
- emit_cmp_and_jump_insns (index,
- convert_modes
- (mode, imode,
- expand_normal (node->high),
- unsignedp),
- GT, NULL_RTX, mode, unsignedp,
- label_rtx (node->right->code_label));
- emit_case_nodes (index, node->left, default_label, index_type);
- }
-
- else if (node_is_bounded (node->left, index_type))
- {
- emit_cmp_and_jump_insns (index,
- convert_modes
- (mode, imode,
- expand_normal (node->high),
- unsignedp),
- LT, NULL_RTX, mode, unsignedp,
- label_rtx (node->left->code_label));
- emit_case_nodes (index, node->right, default_label, index_type);
- }
-
- /* If both children are single-valued cases with no
- children, finish up all the work. This way, we can save
- one ordered comparison. */
- else if (tree_int_cst_equal (node->right->low, node->right->high)
- && node->right->left == 0
- && node->right->right == 0
- && tree_int_cst_equal (node->left->low, node->left->high)
- && node->left->left == 0
- && node->left->right == 0)
- {
- /* Neither node is bounded. First distinguish the two sides;
- then emit the code for one side at a time. */
-
- /* See if the value matches what the right hand side
- wants. */
- do_jump_if_equal (mode, index,
- convert_modes (mode, imode,
- expand_normal (node->right->low),
- unsignedp),
- label_rtx (node->right->code_label),
- unsignedp);
-
- /* See if the value matches what the left hand side
- wants. */
- do_jump_if_equal (mode, index,
- convert_modes (mode, imode,
- expand_normal (node->left->low),
- unsignedp),
- label_rtx (node->left->code_label),
- unsignedp);
- }
-
- else
- {
- /* Neither node is bounded. First distinguish the two sides;
- then emit the code for one side at a time. */
-
- tree test_label
- = build_decl (CURR_INSN_LOCATION,
- LABEL_DECL, NULL_TREE, NULL_TREE);
-
- /* See if the value is on the right. */
- emit_cmp_and_jump_insns (index,
- convert_modes
- (mode, imode,
- expand_normal (node->high),
- unsignedp),
- GT, NULL_RTX, mode, unsignedp,
- label_rtx (test_label));
-
- /* Value must be on the left.
- Handle the left-hand subtree. */
- emit_case_nodes (index, node->left, default_label, index_type);
- /* If left-hand subtree does nothing,
- go to default. */
- if (default_label)
- emit_jump (default_label);
-
- /* Code branches here for the right-hand subtree. */
- expand_label (test_label);
- emit_case_nodes (index, node->right, default_label, index_type);
- }
- }
+ /* Expand the dispatch as a decrement chain:
- else if (node->right != 0 && node->left == 0)
- {
- /* Here we have a right child but no left so we issue a conditional
- branch to default and process the right child.
+ "switch(index) {case 0: do_0; case 1: do_1; ...; case N: do_N;}"
- Omit the conditional branch to default if the right child
- does not have any children and is single valued; it would
- cost too much space to save so little time. */
+ ==>
- if (node->right->right || node->right->left
- || !tree_int_cst_equal (node->right->low, node->right->high))
- {
- if (!node_has_low_bound (node, index_type))
- {
- emit_cmp_and_jump_insns (index,
- convert_modes
- (mode, imode,
- expand_normal (node->high),
- unsignedp),
- LT, NULL_RTX, mode, unsignedp,
- default_label);
- }
-
- emit_case_nodes (index, node->right, default_label, index_type);
- }
- else
- /* We cannot process node->right normally
- since we haven't ruled out the numbers less than
- this node's value. So handle node->right explicitly. */
- do_jump_if_equal (mode, index,
- convert_modes
- (mode, imode,
- expand_normal (node->right->low),
- unsignedp),
- label_rtx (node->right->code_label), unsignedp);
- }
+ if (index == 0) do_0; else index--;
+ if (index == 0) do_1; else index--;
+ ...
+ if (index == 0) do_N; else index--;
- else if (node->right == 0 && node->left != 0)
- {
- /* Just one subtree, on the left. */
- if (node->left->left || node->left->right
- || !tree_int_cst_equal (node->left->low, node->left->high))
- {
- if (!node_has_high_bound (node, index_type))
- {
- emit_cmp_and_jump_insns (index,
- convert_modes
- (mode, imode,
- expand_normal (node->high),
- unsignedp),
- GT, NULL_RTX, mode, unsignedp,
- default_label);
- }
-
- emit_case_nodes (index, node->left, default_label, index_type);
- }
- else
- /* We cannot process node->left normally
- since we haven't ruled out the numbers less than
- this node's value. So handle node->left explicitly. */
- do_jump_if_equal (mode, index,
- convert_modes
- (mode, imode,
- expand_normal (node->left->low),
- unsignedp),
- label_rtx (node->left->code_label), unsignedp);
+ This is more efficient than a dispatch table on most machines.
+ The last "index--" is redundant but the code is trivially dead
+ and will be cleaned up by later passes. */
+ rtx index = copy_to_mode_reg (index_mode, dispatch_index);
+ rtx zero = CONST0_RTX (index_mode);
+ for (int i = 0; i < ncases; i++)
+ {
+ tree elt = dispatch_table[i];
+ rtx_code_label *lab = jump_target_rtx (CASE_LABEL (elt));
+ do_jump_if_equal (index_mode, index, zero, lab, 0,
+ profile_probability::uninitialized ());
+ force_expand_binop (index_mode, sub_optab,
+ index, CONST1_RTX (index_mode),
+ index, 0, OPTAB_DIRECT);
}
}
else
{
- /* Node is a range. These cases are very similar to those for a single
- value, except that we do not start by testing whether this node
- is the one to branch to. */
-
- if (node->right != 0 && node->left != 0)
+ /* Similar to expand_case, but much simpler. */
+ auto_vec<simple_case_node> case_list;
+ tree index_expr = make_tree (index_type, dispatch_index);
+ tree minval = build_int_cst (index_type, 0);
+ tree maxval = CASE_LOW (dispatch_table.last ());
+ tree range = maxval;
+ rtx_code_label *default_label = gen_label_rtx ();
+
+ for (int i = ncases - 1; i >= 0; --i)
{
- /* Node has subtrees on both sides.
- If the right-hand subtree is bounded,
- test for it first, since we can go straight there.
- Otherwise, we need to make a branch in the control structure,
- then handle the two subtrees. */
- tree test_label = 0;
-
- if (node_is_bounded (node->right, index_type))
- /* Right hand node is fully bounded so we can eliminate any
- testing and branch directly to the target code. */
- emit_cmp_and_jump_insns (index,
- convert_modes
- (mode, imode,
- expand_normal (node->high),
- unsignedp),
- GT, NULL_RTX, mode, unsignedp,
- label_rtx (node->right->code_label));
- else
- {
- /* Right hand node requires testing.
- Branch to a label where we will handle it later. */
-
- test_label = build_decl (CURR_INSN_LOCATION,
- LABEL_DECL, NULL_TREE, NULL_TREE);
- emit_cmp_and_jump_insns (index,
- convert_modes
- (mode, imode,
- expand_normal (node->high),
- unsignedp),
- GT, NULL_RTX, mode, unsignedp,
- label_rtx (test_label));
- }
-
- /* Value belongs to this node or to the left-hand subtree. */
-
- emit_cmp_and_jump_insns (index,
- convert_modes
- (mode, imode,
- expand_normal (node->low),
- unsignedp),
- GE, NULL_RTX, mode, unsignedp,
- label_rtx (node->code_label));
-
- /* Handle the left-hand subtree. */
- emit_case_nodes (index, node->left, default_label, index_type);
-
- /* If right node had to be handled later, do that now. */
-
- if (test_label)
- {
- /* If the left-hand subtree fell through,
- don't let it fall into the right-hand subtree. */
- if (default_label)
- emit_jump (default_label);
-
- expand_label (test_label);
- emit_case_nodes (index, node->right, default_label, index_type);
- }
+ tree elt = dispatch_table[i];
+ tree high = CASE_HIGH (elt);
+ if (high == NULL_TREE)
+ high = CASE_LOW (elt);
+ case_list.safe_push (simple_case_node (CASE_LOW (elt), high,
+ CASE_LABEL (elt)));
}
- else if (node->right != 0 && node->left == 0)
- {
- /* Deal with values to the left of this node,
- if they are possible. */
- if (!node_has_low_bound (node, index_type))
- {
- emit_cmp_and_jump_insns (index,
- convert_modes
- (mode, imode,
- expand_normal (node->low),
- unsignedp),
- LT, NULL_RTX, mode, unsignedp,
- default_label);
- }
-
- /* Value belongs to this node or to the right-hand subtree. */
-
- emit_cmp_and_jump_insns (index,
- convert_modes
- (mode, imode,
- expand_normal (node->high),
- unsignedp),
- LE, NULL_RTX, mode, unsignedp,
- label_rtx (node->code_label));
-
- emit_case_nodes (index, node->right, default_label, index_type);
- }
-
- else if (node->right == 0 && node->left != 0)
- {
- /* Deal with values to the right of this node,
- if they are possible. */
- if (!node_has_high_bound (node, index_type))
- {
- emit_cmp_and_jump_insns (index,
- convert_modes
- (mode, imode,
- expand_normal (node->high),
- unsignedp),
- GT, NULL_RTX, mode, unsignedp,
- default_label);
- }
-
- /* Value belongs to this node or to the left-hand subtree. */
-
- emit_cmp_and_jump_insns (index,
- convert_modes
- (mode, imode,
- expand_normal (node->low),
- unsignedp),
- GE, NULL_RTX, mode, unsignedp,
- label_rtx (node->code_label));
-
- emit_case_nodes (index, node->left, default_label, index_type);
- }
+ emit_case_dispatch_table (index_expr, index_type,
+ case_list, default_label, NULL,
+ minval, maxval, range,
+ BLOCK_FOR_INSN (before_case));
+ emit_label (default_label);
+ }
- else
- {
- /* Node has no children so we check low and high bounds to remove
- redundant tests. Only one of the bounds can exist,
- since otherwise this node is bounded--a case tested already. */
- int high_bound = node_has_high_bound (node, index_type);
- int low_bound = node_has_low_bound (node, index_type);
+ /* Dispatching something not handled? Trap! */
+ expand_builtin_trap ();
- if (!high_bound && low_bound)
- {
- emit_cmp_and_jump_insns (index,
- convert_modes
- (mode, imode,
- expand_normal (node->high),
- unsignedp),
- GT, NULL_RTX, mode, unsignedp,
- default_label);
- }
+ reorder_insns (NEXT_INSN (before_case), get_last_insn (), before_case);
- else if (!low_bound && high_bound)
- {
- emit_cmp_and_jump_insns (index,
- convert_modes
- (mode, imode,
- expand_normal (node->low),
- unsignedp),
- LT, NULL_RTX, mode, unsignedp,
- default_label);
- }
- else if (!low_bound && !high_bound)
- {
- /* Widen LOW and HIGH to the same width as INDEX. */
- tree type = lang_hooks.types.type_for_mode (mode, unsignedp);
- tree low = build1 (CONVERT_EXPR, type, node->low);
- tree high = build1 (CONVERT_EXPR, type, node->high);
- rtx low_rtx, new_index, new_bound;
-
- /* Instead of doing two branches, emit one unsigned branch for
- (index-low) > (high-low). */
- low_rtx = expand_expr (low, NULL_RTX, mode, EXPAND_NORMAL);
- new_index = expand_simple_binop (mode, MINUS, index, low_rtx,
- NULL_RTX, unsignedp,
- OPTAB_WIDEN);
- new_bound = expand_expr (fold_build2 (MINUS_EXPR, type,
- high, low),
- NULL_RTX, mode, EXPAND_NORMAL);
-
- emit_cmp_and_jump_insns (new_index, new_bound, GT, NULL_RTX,
- mode, 1, default_label);
- }
-
- emit_jump (label_rtx (node->code_label));
- }
- }
+ free_temp_slots ();
}
+
+\f
projects / thirdparty / gcc.git / blobdiff