200x-xx-xx Kazu Hirata <kazu@codesourcery.com>
Richard Sandiford <richard@codesourcery.com>
* doc/tm.texi (TARGET_FUNCTION_VALUE): Expand documentation of
parallels.
* calls.c (expand_call): If the return value is a PARALLEL,
extract its first member.
* config/m68k/linux.h (FUNCTION_EXTRA_EPILOGUE): Remove.
* config/m68k/m68k.c (m68k_output_function_epilogue): Don't
use FUNCTION_EXTRA_EPILOGUE.
(m68k_function_value): Return a PARALLEL if the return value
is of a pointer type.
* config/m68k/netbsd-elf.h (current_function_returns_pointer)
(FUNCTION_EXTRA_EPILOGUE): Remove.
* config/m68k/m68k.md (D0_REG): New constant.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@120929
138bc75d-0d04-0410-961f-
82ee72b054a4
+2007-01-18 Kazu Hirata <kazu@codesourcery.com>
+ Richard Sandiford <richard@codesourcery.com>
+
+ * doc/tm.texi (TARGET_FUNCTION_VALUE): Expand documentation of
+ parallels.
+ * calls.c (expand_call): If the return value is a PARALLEL,
+ extract its first member.
+ * config/m68k/linux.h (FUNCTION_EXTRA_EPILOGUE): Remove.
+ * config/m68k/m68k.c (m68k_output_function_epilogue): Don't
+ use FUNCTION_EXTRA_EPILOGUE.
+ (m68k_function_value): Return a PARALLEL if the return value
+ is of a pointer type.
+ * config/m68k/netbsd-elf.h (current_function_returns_pointer)
+ (FUNCTION_EXTRA_EPILOGUE): Remove.
+ * config/m68k/m68k.md (D0_REG): New constant.
+
2007-01-18 Kazu Hirata <kazu@codesourcery.com>
* config/m68k/m68k.c (m68k_output_function_epilogue): Don't
else
valreg = hard_function_value (TREE_TYPE (exp), fndecl, fntype,
(pass == 0));
+
+ /* If VALREG is a PARALLEL whose first member has a zero
+ offset, use that. This is for targets such as m68k that
+ return the same value in multiple places. */
+ if (GET_CODE (valreg) == PARALLEL)
+ {
+ rtx elem = XVECEXP (valreg, 0, 0);
+ rtx where = XEXP (elem, 0);
+ rtx offset = XEXP (elem, 1);
+ if (offset == const0_rtx
+ && GET_MODE (where) == GET_MODE (valreg))
+ valreg = where;
+ }
}
/* Precompute all register parameters. It isn't safe to compute anything
#define FUNCTION_VALUE(VALTYPE, FUNC) \
m68k_function_value (VALTYPE, FUNC)
-/* For compatibility with the large body of existing code which does
- not always properly declare external functions returning pointer
- types, the m68k/SVR4 convention is to copy the value returned for
- pointer functions from a0 to d0 in the function epilogue, so that
- callers that have neglected to properly declare the callee can
- still find the correct return value. */
-
-#define FUNCTION_EXTRA_EPILOGUE(FILE, SIZE) \
-do { \
- if (current_function_returns_pointer \
- && ! find_equiv_reg (0, get_last_insn (), 0, 0, 0, 8, Pmode)) \
- asm_fprintf (FILE, "\tmove.l %Ra0,%Rd0\n"); \
-} while (0);
-
/* Define how to find the value returned by a library function
assuming the value has mode MODE.
For m68k/SVR4 look for integer values in d0, pointer values in d0
if (insn && GET_CODE (insn) == BARRIER)
return;
-#ifdef FUNCTION_EXTRA_EPILOGUE
- FUNCTION_EXTRA_EPILOGUE (stream, size);
-#endif
-
fsize = current_frame.size;
/* FIXME: leaf_function_p below is too strong.
break;
}
- /* If the function returns a pointer, push that into %a0 */
- if (POINTER_TYPE_P (valtype))
- return gen_rtx_REG (mode, 8);
+ /* If the function returns a pointer, push that into %a0. */
+ if (func && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (func))))
+ /* For compatibility with the large body of existing code which
+ does not always properly declare external functions returning
+ pointer types, the m68k/SVR4 convention is to copy the value
+ returned for pointer functions from a0 to d0 in the function
+ epilogue, so that callers that have neglected to properly
+ declare the callee can still find the correct return value in
+ d0. */
+ return gen_rtx_PARALLEL
+ (mode,
+ gen_rtvec (2,
+ gen_rtx_EXPR_LIST (VOIDmode,
+ gen_rtx_REG (mode, A0_REG),
+ const0_rtx),
+ gen_rtx_EXPR_LIST (VOIDmode,
+ gen_rtx_REG (mode, D0_REG),
+ const0_rtx)));
+ else if (POINTER_TYPE_P (valtype))
+ return gen_rtx_REG (mode, A0_REG);
else
- return gen_rtx_REG (mode, 0);
+ return gen_rtx_REG (mode, D0_REG);
}
;; Registers by name.
(define_constants
- [(A0_REG 8)
+ [(D0_REG 0)
+ (A0_REG 8)
(SP_REG 15)
])
m68k_function_value (VALTYPE, FUNC)
-/* For compatibility with the large body of existing code which does
- not always properly declare external functions returning pointer
- types, the m68k/SVR4 convention is to copy the value returned for
- pointer functions from a0 to d0 in the function epilogue, so that
- callers that have neglected to properly declare the callee can
- still find the correct return value. */
-
-extern int current_function_returns_pointer;
-#define FUNCTION_EXTRA_EPILOGUE(FILE, SIZE) \
-do \
- { \
- if (current_function_returns_pointer \
- && ! find_equiv_reg (0, get_last_insn (), 0, 0, 0, 8, Pmode)) \
- asm_fprintf (FILE, "\tmove.l %Ra0,%Rd0\n"); \
- } \
-while (0)
-
-
/* Define how to find the value returned by a library function
assuming the value has mode MODE.
For m68k/SVR4 look for integer values in d0, pointer values in d0
@code{reg} RTX for the hard register where the return value is stored.
The value can also be a @code{parallel} RTX, if the return value is in
multiple places. See @code{FUNCTION_ARG} for an explanation of the
-@code{parallel} form.
+@code{parallel} form. Note that the callee will populate every
+location specified in the @code{parallel}, but if the first element of
+the @code{parallel} contains the whole return value, callers will use
+that element as the canonical location and ignore the others. The m68k
+port uses this type of @code{parallel} to return pointers in both
+@samp{%a0} (the canonical location) and @samp{%d0}.
If @code{TARGET_PROMOTE_FUNCTION_RETURN} returns true, you must apply
the same promotion rules specified in @code{PROMOTE_MODE} if
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