return 1;
}
-#define RET_INT_REGS 2
-#define RET_SSE_REGS 2
-
-/* Check if the structure in value_type is returned in registers or in
- memory. If this function returns 1, GDB will call
- STORE_STRUCT_RETURN and EXTRACT_STRUCT_VALUE_ADDRESS else
- STORE_RETURN_VALUE and EXTRACT_RETURN_VALUE will be used. */
-
-static int
-x86_64_use_struct_convention (int gcc_p, struct type *value_type)
-{
- enum x86_64_reg_class class[MAX_CLASSES];
- int n = classify_argument (value_type, class, 0);
- int needed_intregs;
- int needed_sseregs;
-
- return (!n ||
- !examine_argument (class, n, &needed_intregs, &needed_sseregs) ||
- needed_intregs > RET_INT_REGS || needed_sseregs > RET_SSE_REGS);
-}
-
-/* Extract from an array REGBUF containing the (raw) register state, a
- function return value of TYPE, and copy that, in virtual format,
- into VALBUF. */
-
-static void
-x86_64_extract_return_value (struct type *type, struct regcache *regcache,
- void *valbuf)
-{
- enum x86_64_reg_class class[MAX_CLASSES];
- int n = classify_argument (type, class, 0);
- int needed_intregs;
- int needed_sseregs;
- int intreg = 0;
- int ssereg = 0;
- int offset = 0;
- int ret_int_r[RET_INT_REGS] = { X86_64_RAX_REGNUM, X86_64_RDX_REGNUM };
- int ret_sse_r[RET_SSE_REGS] = { X86_64_XMM0_REGNUM, X86_64_XMM1_REGNUM };
-
- if (!n ||
- !examine_argument (class, n, &needed_intregs, &needed_sseregs) ||
- needed_intregs > RET_INT_REGS || needed_sseregs > RET_SSE_REGS)
- { /* memory class */
- CORE_ADDR addr;
- regcache_cooked_read (regcache, X86_64_RAX_REGNUM, &addr);
- read_memory (addr, valbuf, TYPE_LENGTH (type));
- return;
- }
- else
- {
- int i;
- for (i = 0; i < n; i++)
- {
- switch (class[i])
- {
- case X86_64_NO_CLASS:
- break;
- case X86_64_INTEGER_CLASS:
- regcache_cooked_read (regcache, ret_int_r[(intreg + 1) / 2],
- (char *) valbuf + offset);
- offset += 8;
- intreg += 2;
- break;
- case X86_64_INTEGERSI_CLASS:
- regcache_cooked_read_part (regcache, ret_int_r[intreg / 2],
- 0, 4, (char *) valbuf + offset);
- offset += 8;
- intreg++;
- break;
- case X86_64_SSEDF_CLASS:
- case X86_64_SSESF_CLASS:
- case X86_64_SSE_CLASS:
- regcache_cooked_read_part (regcache,
- ret_sse_r[(ssereg + 1) / 2], 0, 8,
- (char *) valbuf + offset);
- offset += 8;
- ssereg += 2;
- break;
- case X86_64_SSEUP_CLASS:
- regcache_cooked_read_part (regcache, ret_sse_r[ssereg / 2],
- 0, 8, (char *) valbuf + offset);
- offset += 8;
- ssereg++;
- break;
- case X86_64_X87_CLASS:
- regcache_cooked_read_part (regcache, X86_64_ST0_REGNUM,
- 0, 8, (char *) valbuf + offset);
- offset += 8;
- break;
- case X86_64_X87UP_CLASS:
- regcache_cooked_read_part (regcache, X86_64_ST0_REGNUM,
- 8, 2, (char *) valbuf + offset);
- offset += 8;
- break;
- case X86_64_MEMORY_CLASS:
- default:
- internal_error (__FILE__, __LINE__,
- "Unexpected argument class");
- }
- }
- }
-}
-
#define INT_REGS 6
#define SSE_REGS 8
return sp;
}
-/* Write into the appropriate registers a function return value stored
- in VALBUF of type TYPE, given in virtual format. */
+/* Register classes as defined in the psABI. */
+
+enum amd64_reg_class
+{
+ AMD64_INTEGER,
+ AMD64_SSE,
+ AMD64_SSEUP,
+ AMD64_X87,
+ AMD64_X87UP,
+ AMD64_COMPLEX_X87,
+ AMD64_NO_CLASS,
+ AMD64_MEMORY
+};
+
+/* Return the union class of CLASS1 and CLASS2. See the psABI for
+ details. */
+
+static enum amd64_reg_class
+amd64_merge_classes (enum amd64_reg_class class1, enum amd64_reg_class class2)
+{
+ /* Rule (a): If both classes are equal, this is the resulting class. */
+ if (class1 == class2)
+ return class1;
+
+ /* Rule (b): If one of the classes is NO_CLASS, the resulting class
+ is the other class. */
+ if (class1 == AMD64_NO_CLASS)
+ return class2;
+ if (class2 == AMD64_NO_CLASS)
+ return class1;
+
+ /* Rule (c): If one of the classes is MEMORY, the result is MEMORY. */
+ if (class1 == AMD64_MEMORY || class2 == AMD64_MEMORY)
+ return AMD64_MEMORY;
+
+ /* Rule (d): If one of the classes is INTEGER, the result is INTEGER. */
+ if (class1 == AMD64_INTEGER || class2 == AMD64_INTEGER)
+ return AMD64_INTEGER;
+
+ /* Rule (e): If one of the classes is X87, X87UP, COMPLEX_X87 class,
+ MEMORY is used as class. */
+ if (class1 == AMD64_X87 || class1 == AMD64_X87UP
+ || class1 == AMD64_COMPLEX_X87 || class2 == AMD64_X87
+ || class2 == AMD64_X87UP || class2 == AMD64_COMPLEX_X87)
+ return AMD64_MEMORY;
+
+ /* Rule (f): Otherwise class SSE is used. */
+ return AMD64_SSE;
+}
+
+static void amd64_classify (struct type *type, enum amd64_reg_class class[2]);
+
+/* Classify TYPE according to the rules for aggregate (structures and
+ arrays) and union types, and store the result in CLASS. */
static void
-x86_64_store_return_value (struct type *type, struct regcache *regcache,
- const void *valbuf)
+amd64_classify_aggregate (struct type *type, enum amd64_reg_class class[2])
{
int len = TYPE_LENGTH (type);
- /* First handle long doubles. */
- if (TYPE_CODE_FLT == TYPE_CODE (type) && len == 16)
+ /* 1. If the size of an object is larger than two eightbytes, or in
+ C++, is a non-POD structure or union type, or contains
+ unaligned fields, it has class memory. */
+ if (len > 16)
{
- ULONGEST fstat;
- char buf[I386_MAX_REGISTER_SIZE];
-
- /* Returning floating-point values is a bit tricky. Apart from
- storing the return value in %st(0), we have to simulate the
- state of the FPU at function return point. */
-
- /* Convert the value found in VALBUF to the extended
- floating-point format used by the FPU. This is probably
- not exactly how it would happen on the target itself, but
- it is the best we can do. */
- convert_typed_floating (valbuf, type, buf, builtin_type_i387_ext);
- regcache_raw_write (regcache, X86_64_ST0_REGNUM, buf);
-
- /* Set the top of the floating-point register stack to 7. The
- actual value doesn't really matter, but 7 is what a normal
- function return would end up with if the program started out
- with a freshly initialized FPU. */
- regcache_raw_read_unsigned (regcache, FSTAT_REGNUM, &fstat);
- fstat |= (7 << 11);
- regcache_raw_write_unsigned (regcache, FSTAT_REGNUM, fstat);
-
- /* Mark %st(1) through %st(7) as empty. Since we set the top of
- the floating-point register stack to 7, the appropriate value
- for the tag word is 0x3fff. */
- regcache_raw_write_unsigned (regcache, FTAG_REGNUM, 0x3fff);
+ class[0] = class[1] = AMD64_MEMORY;
+ return;
}
- else if (TYPE_CODE_FLT == TYPE_CODE (type))
+
+ /* 2. Both eightbytes get initialized to class NO_CLASS. */
+ class[0] = class[1] = AMD64_NO_CLASS;
+
+ /* 3. Each field of an object is classified recursively so that
+ always two fields are considered. The resulting class is
+ calculated according to the classes of the fields in the
+ eightbyte: */
+
+ if (TYPE_CODE (type) == TYPE_CODE_ARRAY)
{
- /* Handle double and float variables. */
- regcache_cooked_write_part (regcache, X86_64_XMM0_REGNUM,
- 0, len, valbuf);
+ struct type *subtype = check_typedef (TYPE_TARGET_TYPE (type));
+
+ /* All fields in an array have the same type. */
+ amd64_classify (subtype, class);
+ if (len > 8 && class[1] == AMD64_NO_CLASS)
+ class[1] = class[0];
}
- /* XXX: What about complex floating point types? */
else
{
- int low_size = register_size (current_gdbarch, X86_64_RAX_REGNUM);
- int high_size = register_size (current_gdbarch, X86_64_RDX_REGNUM);
+ int i;
- if (len <= low_size)
- regcache_cooked_write_part (regcache, 0, 0, len, valbuf);
- else if (len <= (low_size + high_size))
+ /* Structure or union. */
+ gdb_assert (TYPE_CODE (type) == TYPE_CODE_STRUCT
+ || TYPE_CODE (type) == TYPE_CODE_UNION);
+
+ for (i = 0; i < TYPE_NFIELDS (type); i++)
{
- regcache_cooked_write_part (regcache, 0, 0, low_size, valbuf);
- regcache_cooked_write_part (regcache, 1, 0,
- len - low_size,
- (const char *) valbuf + low_size);
+ struct type *subtype = check_typedef (TYPE_FIELD_TYPE (type, i));
+ int pos = TYPE_FIELD_BITPOS (type, i) / 64;
+ enum amd64_reg_class subclass[2];
+
+ gdb_assert (pos == 0 || pos == 1);
+
+ amd64_classify (subtype, subclass);
+ class[pos] = amd64_merge_classes (class[pos], subclass[0]);
+ if (pos == 0)
+ class[1] = amd64_merge_classes (class[1], subclass[1]);
}
- else
- internal_error (__FILE__, __LINE__,
- "Cannot store return value of %d bytes long.", len);
}
+
+ /* 4. Then a post merger cleanup is done: */
+
+ /* Rule (a): If one of the classes is MEMORY, the whole argument is
+ passed in memory. */
+ if (class[0] == AMD64_MEMORY || class[1] == AMD64_MEMORY)
+ class[0] = class[1] = AMD64_MEMORY;
+
+ /* Rule (b): If SSEUP is not preceeded by SSE, it is converted to
+ SSE. */
+ if (class[0] == AMD64_SSEUP)
+ class[0] = AMD64_SSE;
+ if (class[1] == AMD64_SSEUP && class[0] != AMD64_SSE)
+ class[1] = AMD64_SSE;
+}
+
+/* Classify TYPE, and store the result in CLASS. */
+
+static void
+amd64_classify (struct type *type, enum amd64_reg_class class[2])
+{
+ enum type_code code = TYPE_CODE (type);
+ int len = TYPE_LENGTH (type);
+
+ class[0] = class[1] = AMD64_NO_CLASS;
+
+ /* Arguments of types (signed and unsigned) _Bool, char, short, int,
+ long, long long, and pointers are in the INTEGER class. */
+ if ((code == TYPE_CODE_INT || code == TYPE_CODE_ENUM
+ || code == TYPE_CODE_PTR || code == TYPE_CODE_REF)
+ && (len == 1 || len == 2 || len == 4 || len == 8))
+ class[0] = AMD64_INTEGER;
+
+ /* Arguments of types float, double and __m64 are in class SSE. */
+ else if (code == TYPE_CODE_FLT && (len == 4 || len == 8))
+ /* FIXME: __m64 . */
+ class[0] = AMD64_SSE;
+
+ /* Arguments of types __float128 and __m128 are split into two
+ halves. The least significant ones belong to class SSE, the most
+ significant one to class SSEUP. */
+ /* FIXME: __float128, __m128. */
+
+ /* The 64-bit mantissa of arguments of type long double belongs to
+ class X87, the 16-bit exponent plus 6 bytes of padding belongs to
+ class X87UP. */
+ else if (code == TYPE_CODE_FLT && len == 16)
+ /* Class X87 and X87UP. */
+ class[0] = AMD64_X87, class[1] = AMD64_X87UP;
+
+ /* Aggregates. */
+ else if (code == TYPE_CODE_ARRAY || code == TYPE_CODE_STRUCT
+ || code == TYPE_CODE_UNION)
+ amd64_classify_aggregate (type, class);
+}
+
+static enum return_value_convention
+amd64_return_value (struct gdbarch *gdbarch, struct type *type,
+ struct regcache *regcache,
+ void *readbuf, const void *writebuf)
+{
+ enum amd64_reg_class class[2];
+ int len = TYPE_LENGTH (type);
+ static int integer_regnum[] = { X86_64_RAX_REGNUM, X86_64_RDX_REGNUM };
+ static int sse_regnum[] = { X86_64_XMM0_REGNUM, X86_64_XMM1_REGNUM };
+ int integer_reg = 0;
+ int sse_reg = 0;
+ int i;
+
+ gdb_assert (!(readbuf && writebuf));
+
+ /* 1. Classify the return type with the classification algorithm. */
+ amd64_classify (type, class);
+
+ /* 2. If the type has class MEMORY, then the caller provides space
+ for the return value and passes the address of this storage in
+ %rdi as if it were the first argument to the function. In
+ effect, this address becomes a hidden first argument. */
+ if (class[0] == AMD64_MEMORY)
+ return RETURN_VALUE_STRUCT_CONVENTION;
+
+ gdb_assert (class[1] != AMD64_MEMORY);
+ gdb_assert (len <= 16);
+
+ for (i = 0; len > 0; i++, len -= 8)
+ {
+ int regnum = -1;
+ int offset = 0;
+
+ switch (class[i])
+ {
+ case AMD64_INTEGER:
+ /* 3. If the class is INTEGER, the next available register
+ of the sequence %rax, %rdx is used. */
+ regnum = integer_regnum[integer_reg++];
+ break;
+
+ case AMD64_SSE:
+ /* 4. If the class is SSE, the next available SSE register
+ of the sequence %xmm0, %xmm1 is used. */
+ regnum = sse_regnum[sse_reg++];
+ break;
+
+ case AMD64_SSEUP:
+ /* 5. If the class is SSEUP, the eightbyte is passed in the
+ upper half of the last used SSE register. */
+ gdb_assert (sse_reg > 0);
+ regnum = sse_regnum[sse_reg - 1];
+ offset = 8;
+ break;
+
+ case AMD64_X87:
+ /* 6. If the class is X87, the value is returned on the X87
+ stack in %st0 as 80-bit x87 number. */
+ regnum = X86_64_ST0_REGNUM;
+ if (writebuf)
+ i387_return_value (gdbarch, regcache);
+ break;
+
+ case AMD64_X87UP:
+ /* 7. If the class is X87UP, the value is returned together
+ with the previous X87 value in %st0. */
+ gdb_assert (i > 0 && class[0] == AMD64_X87);
+ regnum = X86_64_ST0_REGNUM;
+ offset = 8;
+ len = 2;
+ break;
+
+ case AMD64_NO_CLASS:
+ continue;
+
+ default:
+ gdb_assert (!"Unexpected register class.");
+ }
+
+ gdb_assert (regnum != -1);
+
+ if (readbuf)
+ regcache_raw_read_part (regcache, regnum, offset, min (len, 8),
+ (char *) readbuf + i * 8);
+ if (writebuf)
+ regcache_raw_write_part (regcache, regnum, offset, min (len, 8),
+ (const char *) writebuf + i * 8);
+ }
+
+ return RETURN_VALUE_REGISTER_CONVENTION;
}
\f
set_gdbarch_register_to_value (gdbarch, i387_register_to_value);
set_gdbarch_value_to_register (gdbarch, i387_value_to_register);
- set_gdbarch_return_value (gdbarch, NULL);
- set_gdbarch_extract_return_value (gdbarch, x86_64_extract_return_value);
- set_gdbarch_store_return_value (gdbarch, x86_64_store_return_value);
+ set_gdbarch_return_value (gdbarch, amd64_return_value);
/* Override, since this is handled by x86_64_extract_return_value. */
set_gdbarch_extract_struct_value_address (gdbarch, NULL);
- set_gdbarch_use_struct_convention (gdbarch, x86_64_use_struct_convention);
set_gdbarch_skip_prologue (gdbarch, x86_64_skip_prologue);
projects / thirdparty / binutils-gdb.git / commitdiff
