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explow.c (allocate_dynamic_stack_space SETJMP_VIA_SAVE_AREA): Kill setjmpless_size.
* explow.c (allocate_dynamic_stack_space SETJMP_VIA_SAVE_AREA): Kill setjmpless_size. current_function_calls_setjmp is completely computed when we are called, so just use the optimized size value instead of using REG_SAVE_AREA notes. (optimize_save_area_alloca): Delete.... * rtl.h (optimize_save_area_alloca): Likewise... * passes.c (rest_of_compilation): and don't call it any more. * reg-notes.def (SAVE_AREA): Delete. From-SVN: r98861
This commit is contained in:
David S. Miller
David S. Miller
parent
25b9575bc2
commit
d0828b3113
@ -1,3 +1,14 @@
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2005-04-27 David S. Miller <davem@davemloft.net>
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* explow.c (allocate_dynamic_stack_space SETJMP_VIA_SAVE_AREA):
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Kill setjmpless_size. current_function_calls_setjmp is completely
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computed when we are called, so just use the optimized size value
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instead of using REG_SAVE_AREA notes.
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(optimize_save_area_alloca): Delete....
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* rtl.h (optimize_save_area_alloca): Likewise...
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* passes.c (rest_of_compilation): and don't call it any more.
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* reg-notes.def (SAVE_AREA): Delete.
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2005-04-27 Nathan Sidwell <nathan@codesourcery.com>
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* config/fp-bit.c (abort): Add noreturn attribute.
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167
gcc/explow.c
167
gcc/explow.c
@ -1017,83 +1017,6 @@ update_nonlocal_goto_save_area (void)
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emit_stack_save (SAVE_NONLOCAL, &r_save, NULL_RTX);
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}
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#ifdef SETJMP_VIA_SAVE_AREA
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/* Optimize RTL generated by allocate_dynamic_stack_space for targets
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where SETJMP_VIA_SAVE_AREA is true. The problem is that on these
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platforms, the dynamic stack space used can corrupt the original
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frame, thus causing a crash if a longjmp unwinds to it. */
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void
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optimize_save_area_alloca (void)
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{
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rtx insn;
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for (insn = get_insns (); insn; insn = NEXT_INSN(insn))
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{
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rtx note;
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if (!NONJUMP_INSN_P (insn))
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continue;
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for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
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{
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if (REG_NOTE_KIND (note) != REG_SAVE_AREA)
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continue;
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if (!current_function_calls_setjmp)
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{
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rtx pat = PATTERN (insn);
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/* If we do not see the note in a pattern matching
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these precise characteristics, we did something
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entirely wrong in allocate_dynamic_stack_space.
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Note, one way this could happen is if SETJMP_VIA_SAVE_AREA
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was defined on a machine where stacks grow towards higher
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addresses.
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Right now only supported port with stack that grow upward
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is the HPPA and it does not define SETJMP_VIA_SAVE_AREA. */
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gcc_assert (GET_CODE (pat) == SET
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&& SET_DEST (pat) == stack_pointer_rtx
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&& GET_CODE (SET_SRC (pat)) == MINUS
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&& XEXP (SET_SRC (pat), 0) == stack_pointer_rtx);
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/* This will now be transformed into a (set REG REG)
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so we can just blow away all the other notes. */
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XEXP (SET_SRC (pat), 1) = XEXP (note, 0);
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REG_NOTES (insn) = NULL_RTX;
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}
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else
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{
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/* setjmp was called, we must remove the REG_SAVE_AREA
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note so that later passes do not get confused by its
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presence. */
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if (note == REG_NOTES (insn))
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{
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REG_NOTES (insn) = XEXP (note, 1);
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}
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else
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{
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rtx srch;
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for (srch = REG_NOTES (insn); srch; srch = XEXP (srch, 1))
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if (XEXP (srch, 1) == note)
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break;
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gcc_assert (srch);
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XEXP (srch, 1) = XEXP (note, 1);
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}
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}
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/* Once we've seen the note of interest, we need not look at
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the rest of them. */
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break;
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}
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}
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}
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#endif /* SETJMP_VIA_SAVE_AREA */
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/* Return an rtx representing the address of an area of memory dynamically
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pushed on the stack. This region of memory is always aligned to
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a multiple of BIGGEST_ALIGNMENT.
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@ -1108,10 +1031,6 @@ optimize_save_area_alloca (void)
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rtx
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allocate_dynamic_stack_space (rtx size, rtx target, int known_align)
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{
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#ifdef SETJMP_VIA_SAVE_AREA
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rtx setjmpless_size = NULL_RTX;
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#endif
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/* If we're asking for zero bytes, it doesn't matter what we point
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to since we can't dereference it. But return a reasonable
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address anyway. */
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@ -1160,51 +1079,47 @@ allocate_dynamic_stack_space (rtx size, rtx target, int known_align)
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avoid clobbering the reg save area. Note that the offset of
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virtual_incoming_args_rtx includes the preallocated stack args space.
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It would be no problem to clobber that, but it's on the wrong side
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of the old save area. */
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{
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rtx dynamic_offset
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= expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx,
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stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN);
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of the old save area.
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if (!current_function_calls_setjmp)
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{
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int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
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What used to happen is that, since we did not know for sure
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whether setjmp() was invoked until after RTL generation, we
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would use reg notes to store the "optimized" size and fix things
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up later. These days we know this information before we ever
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start building RTL so the reg notes are unnecessary. */
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if (!current_function_calls_setjmp)
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{
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int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
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/* See optimize_save_area_alloca to understand what is being
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set up here. */
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/* ??? Code below assumes that the save area needs maximal
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alignment. This constraint may be too strong. */
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gcc_assert (PREFERRED_STACK_BOUNDARY == BIGGEST_ALIGNMENT);
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/* ??? Code below assumes that the save area needs maximal
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alignment. This constraint may be too strong. */
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gcc_assert (PREFERRED_STACK_BOUNDARY == BIGGEST_ALIGNMENT);
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if (GET_CODE (size) == CONST_INT)
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{
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HOST_WIDE_INT new = INTVAL (size) / align * align;
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if (GET_CODE (size) == CONST_INT)
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{
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HOST_WIDE_INT new = INTVAL (size) / align * align;
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if (INTVAL (size) != new)
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size = GEN_INT (new);
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}
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else
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{
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/* Since we know overflow is not possible, we avoid using
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CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */
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size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size,
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GEN_INT (align), NULL_RTX, 1);
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size = expand_mult (Pmode, size,
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GEN_INT (align), NULL_RTX, 1);
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}
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}
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else
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{
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rtx dynamic_offset
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= expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx,
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stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN);
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if (INTVAL (size) != new)
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setjmpless_size = GEN_INT (new);
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else
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setjmpless_size = size;
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}
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else
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{
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/* Since we know overflow is not possible, we avoid using
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CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */
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setjmpless_size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size,
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GEN_INT (align), NULL_RTX, 1);
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setjmpless_size = expand_mult (Pmode, setjmpless_size,
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GEN_INT (align), NULL_RTX, 1);
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}
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/* Our optimization works based upon being able to perform a simple
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transformation of this RTL into a (set REG REG) so make sure things
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did in fact end up in a REG. */
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if (!register_operand (setjmpless_size, Pmode))
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setjmpless_size = force_reg (Pmode, setjmpless_size);
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}
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size = expand_binop (Pmode, add_optab, size, dynamic_offset,
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NULL_RTX, 1, OPTAB_LIB_WIDEN);
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}
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size = expand_binop (Pmode, add_optab, size, dynamic_offset,
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NULL_RTX, 1, OPTAB_LIB_WIDEN);
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}
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#endif /* SETJMP_VIA_SAVE_AREA */
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/* Round the size to a multiple of the required stack alignment.
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@ -1304,16 +1219,6 @@ allocate_dynamic_stack_space (rtx size, rtx target, int known_align)
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}
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anti_adjust_stack (size);
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#ifdef SETJMP_VIA_SAVE_AREA
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if (setjmpless_size != NULL_RTX)
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{
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rtx note_target = get_last_insn ();
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REG_NOTES (note_target)
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= gen_rtx_EXPR_LIST (REG_SAVE_AREA, setjmpless_size,
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REG_NOTES (note_target));
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}
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#endif /* SETJMP_VIA_SAVE_AREA */
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#ifdef STACK_GROWS_DOWNWARD
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emit_move_insn (target, virtual_stack_dynamic_rtx);
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@ -1558,15 +1558,6 @@ rest_of_compilation (void)
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/* Copy any shared structure that should not be shared. */
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unshare_all_rtl ();
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#ifdef SETJMP_VIA_SAVE_AREA
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/* This must be performed before virtual register instantiation.
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Please be aware that everything in the compiler that can look
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at the RTL up to this point must understand that REG_SAVE_AREA
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is just like a use of the REG contained inside. */
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if (current_function_calls_alloca)
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optimize_save_area_alloca ();
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#endif
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/* Instantiate all virtual registers. */
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instantiate_virtual_regs ();
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@ -117,10 +117,6 @@ REG_NOTE (VALUE_PROFILE)
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that the pointer returned cannot alias anything else. */
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REG_NOTE (NOALIAS)
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/* Used to optimize rtl generated by dynamic stack allocations for
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targets where SETJMP_VIA_SAVE_AREA is true. */
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REG_NOTE (SAVE_AREA)
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/* REG_BR_PRED is attached to JUMP_INSNs and CALL_INSNSs. It contains
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CONCAT of two integer value. First specifies the branch predictor
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that added the note, second specifies the predicted hitrate of
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@ -1320,7 +1320,6 @@ extern rtx expand_builtin_expect_jump (tree, rtx, rtx);
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extern void set_stack_check_libfunc (rtx);
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extern HOST_WIDE_INT trunc_int_for_mode (HOST_WIDE_INT, enum machine_mode);
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extern rtx plus_constant (rtx, HOST_WIDE_INT);
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extern void optimize_save_area_alloca (void);
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/* In emit-rtl.c */
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extern rtvec gen_rtvec (int, ...);
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