[gcc12,backport] PR target/105930: Split *xordi3_doubleword after reload on x86.
Commit Message
This is a backport of the fix for PR target/105930 from mainline to the
gcc12 release branch. This patch has been retested against the gcc12
branch on x86_64-pc-linux-gnu with make bootstrap and make -k check,
both with and without --target_board=unix{-m32} with no new failures.
Ok for the gcc12 branch?
2022-07-09 Roger Sayle <roger@nextmovesoftware.com>
Uroš Bizjak <ubizjak@gmail.com>
gcc/ChangeLog
PR target/105930
* config/i386/i386.md (*<any_or>di3_doubleword): Split after
reload. Use rtx_equal_p to avoid creating memory-to-memory moves,
and emit NOTE_INSN_DELETED if operand[2] is zero (i.e. with -O0).
Thanks in advance,
Roger
--
Comments
On Sat, Jul 9, 2022 at 11:26 AM Roger Sayle <roger@nextmovesoftware.com> wrote:
>
>
> This is a backport of the fix for PR target/105930 from mainline to the
> gcc12 release branch. This patch has been retested against the gcc12
> branch on x86_64-pc-linux-gnu with make bootstrap and make -k check,
> both with and without --target_board=unix{-m32} with no new failures.
> Ok for the gcc12 branch?
>
>
> 2022-07-09 Roger Sayle <roger@nextmovesoftware.com>
> Uroš Bizjak <ubizjak@gmail.com>
>
> gcc/ChangeLog
> PR target/105930
> * config/i386/i386.md (*<any_or>di3_doubleword): Split after
> reload. Use rtx_equal_p to avoid creating memory-to-memory moves,
> and emit NOTE_INSN_DELETED if operand[2] is zero (i.e. with -O0).
OK.
Thanks,
Uros.
>
> Thanks in advance,
> Roger
> --
>
@@ -10400,22 +10400,25 @@
"ix86_expand_binary_operator (<CODE>, <MODE>mode, operands); DONE;")
(define_insn_and_split "*<code>di3_doubleword"
- [(set (match_operand:DI 0 "nonimmediate_operand")
+ [(set (match_operand:DI 0 "nonimmediate_operand" "=ro,r")
(any_or:DI
- (match_operand:DI 1 "nonimmediate_operand")
- (match_operand:DI 2 "x86_64_szext_general_operand")))
+ (match_operand:DI 1 "nonimmediate_operand" "0,0")
+ (match_operand:DI 2 "x86_64_szext_general_operand" "re,o")))
(clobber (reg:CC FLAGS_REG))]
"!TARGET_64BIT
- && ix86_binary_operator_ok (<CODE>, DImode, operands)
- && ix86_pre_reload_split ()"
+ && ix86_binary_operator_ok (<CODE>, DImode, operands)"
"#"
- "&& 1"
+ "&& reload_completed"
[(const_int 0)]
{
+ /* This insn may disappear completely when operands[2] == const0_rtx
+ and operands[0] == operands[1], which requires a NOTE_INSN_DELETED. */
+ bool emit_insn_deleted_note_p = false;
+
split_double_mode (DImode, &operands[0], 3, &operands[0], &operands[3]);
if (operands[2] == const0_rtx)
- emit_move_insn (operands[0], operands[1]);
+ emit_insn_deleted_note_p = true;
else if (operands[2] == constm1_rtx)
{
if (<CODE> == IOR)
@@ -10427,7 +10430,10 @@
ix86_expand_binary_operator (<CODE>, SImode, &operands[0]);
if (operands[5] == const0_rtx)
- emit_move_insn (operands[3], operands[4]);
+ {
+ if (emit_insn_deleted_note_p)
+ emit_note (NOTE_INSN_DELETED);
+ }
else if (operands[5] == constm1_rtx)
{
if (<CODE> == IOR)