+2002-10-02 Roger Sayle <roger@eyesopen.com>
+
+ PR optimization/6627
+ * toplev.c (force_align_functions_log): New global variable.
+ * flags.h (force_align_functions_log): Add extern prototype.
+ * varasm.c (assemble_start_function): Use it to force minimum
+ function alignment.
+ * config/i386/i386.h (FUNCTION_BOUNDARY): Set the correct
+ minimum function alignment to one byte.
+ (TARGET_PTRMEMFUNC_VBIT_LOCATION): Store the virtual bit in
+ the least significant bit of vtable member function pointers.
+ * tree.h (enum ptrmemfunc_vbit_where_t): Move definition to
+ here from cp/cp-tree.h.
+
2002-10-02 Matt Austern <austern@apple.com>
* cp/decl.c (walk_vtables_r): Fixed typo that caused result to
never get a nonzero value.
#define FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN \
(ix86_preferred_stack_boundary > STACK_BOUNDARY && !TARGET_64BIT)
-/* Allocation boundary for the code of a function. */
-#define FUNCTION_BOUNDARY 16
+/* Minimum allocation boundary for the code of a function. */
+#define FUNCTION_BOUNDARY 8
+
+/* C++ stores the virtual bit in the lowest bit of function pointers. */
+#define TARGET_PTRMEMFUNC_VBIT_LOCATION ptrmemfunc_vbit_in_pfn
/* Alignment of field after `int : 0' in a structure. */
+2002-10-02 Roger Sayle <roger@eyesopen.com>
+
+ PR optimization/6627
+ * cp-tree.h (enum ptrmemfunc_vbit_where_t): Delete definition
+ from here, and move it to tree.h.
+ * decl.c (cxx_init_decl_processing): If storing the vbit
+ in function pointers, ensure that force_align_functions_log
+ is atleast one.
+
2002-10-01 Mark Mitchell <mark@codesourcery.com>
* decl.c (cp_finish_decl): Make sure array types are laid out,
member function. [expr.unary.op]/3 */
#define PTRMEM_OK_P(NODE) TREE_LANG_FLAG_0 (NODE)
-/* A pointer-to-function member type looks like:
-
- struct {
- __P __pfn;
- ptrdiff_t __delta;
- };
-
- If __pfn is NULL, it is a NULL pointer-to-member-function.
-
- (Because the vtable is always the first thing in the object, we
- don't need its offset.) If the function is virtual, then PFN is
- one plus twice the index into the vtable; otherwise, it is just a
- pointer to the function.
-
- Unfortunately, using the lowest bit of PFN doesn't work in
- architectures that don't impose alignment requirements on function
- addresses, or that use the lowest bit to tell one ISA from another,
- for example. For such architectures, we use the lowest bit of
- DELTA instead of the lowest bit of the PFN, and DELTA will be
- multiplied by 2. */
-enum ptrmemfunc_vbit_where_t
-{
- ptrmemfunc_vbit_in_pfn,
- ptrmemfunc_vbit_in_delta
-};
-
/* Get the POINTER_TYPE to the METHOD_TYPE associated with this
pointer to member function. TYPE_PTRMEMFUNC_P _must_ be true,
before using this macro. */
flag_inline_functions = 0;
}
+ /* Force minimum function alignment if using the least significant
+ bit of function pointers to store the virtual bit. */
+ if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_pfn
+ && force_align_functions_log < 1)
+ force_align_functions_log = 1;
+
/* Initially, C. */
current_lang_name = lang_name_c;
extern int align_functions;
extern int align_functions_log;
+/* Like align_functions_log above, but used by front-ends to force the
+ minimum function alignment. Zero means no alignment is forced. */
+extern int force_align_functions_log;
+
/* Nonzero if we dump in VCG format, not plain text. */
extern int dump_for_graph;
+2002-10-02 Roger Sayle <roger@eyesopen.com>
+
+ PR optimization/6627
+ * lang.c (java_init): If storing the vbit in function
+ pointers, ensure that force_align_functions_log is atleast
+ one to aid compatability with g++ vtables.
+
2002-10-01 Nathan Sidwell <nathan@codesourcery.com>
* jcf-dump.c (print_constant, case CONSTANT_float): Don't fall
if (flag_inline_functions)
flag_inline_trees = 1;
+ /* Force minimum function alignment if g++ uses the least significant
+ bit of function pointers to store the virtual bit. This is required
+ to keep vtables compatible. */
+ if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_pfn
+ && force_align_functions_log < 1)
+ force_align_functions_log = 1;
+
/* Open input file. */
if (filename == 0 || !strcmp (filename, "-"))
int align_functions;
int align_functions_log;
+/* Like align_functions_log above, but used by front-ends to force the
+ minimum function alignment. Zero means no alignment is forced. */
+int force_align_functions_log;
+
/* Table of supported debugging formats. */
static const struct
{
extern enum tls_model flag_tls_default;
\f
+/* A pointer-to-function member type looks like:
+
+ struct {
+ __P __pfn;
+ ptrdiff_t __delta;
+ };
+
+ If __pfn is NULL, it is a NULL pointer-to-member-function.
+
+ (Because the vtable is always the first thing in the object, we
+ don't need its offset.) If the function is virtual, then PFN is
+ one plus twice the index into the vtable; otherwise, it is just a
+ pointer to the function.
+
+ Unfortunately, using the lowest bit of PFN doesn't work in
+ architectures that don't impose alignment requirements on function
+ addresses, or that use the lowest bit to tell one ISA from another,
+ for example. For such architectures, we use the lowest bit of
+ DELTA instead of the lowest bit of the PFN, and DELTA will be
+ multiplied by 2. */
+
+enum ptrmemfunc_vbit_where_t
+{
+ ptrmemfunc_vbit_in_pfn,
+ ptrmemfunc_vbit_in_delta
+};
+\f
#define NULL_TREE (tree) NULL
/* Approximate positive square root of a host double. This is for
/* Tell assembler to move to target machine's alignment for functions. */
align = floor_log2 (FUNCTION_BOUNDARY / BITS_PER_UNIT);
+ if (align < force_align_functions_log)
+ align = force_align_functions_log;
if (align > 0)
{
ASM_OUTPUT_ALIGN (asm_out_file, align);
projects / thirdparty / gcc.git / commitdiff
