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i386: Add new pattern for zero-extend cmov

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After a phiopt change, I got a failure of cmov9.c.
The RTL IR has zero_extend on the outside of
the if_then_else rather than on the side. Both
ways are considered canonical as mentioned in
PR 66588.

This fixes the failure I got and also adds a testcase
which fails before even my phiopt patch but will pass
with this patch.

OK? Bootstrapped and tested on x86_64-linux-gnu with
no regressions.

gcc/ChangeLog:

	* config/i386/i386.md (*movsicc_noc_zext_1): New pattern.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/cmov10.c: New test.
	* gcc.target/i386/cmov11.c: New test.
This commit is contained in:
Andrew Pinski 2023-04-13 00:40:40 +00:00
parent ed32ec2669
commit 04a9209dc8
3 changed files with 36 additions and 0 deletions
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16
gcc/config/i386/i386.md
View file

@ -22033,6 +22033,22 @@
[(set_attr "type" "icmov")
(set_attr "mode" "SI")])
(define_insn "*movsicc_noc_zext_1"
[(set (match_operand:DI 0 "nonimmediate_operand" "=r,r")
(zero_extend:DI
(if_then_else:SI (match_operator 1 "ix86_comparison_operator"
[(reg FLAGS_REG) (const_int 0)])
(match_operand:SI 2 "nonimmediate_operand" "rm,0")
(match_operand:SI 3 "nonimmediate_operand" "0,rm"))))]
"TARGET_64BIT
&& TARGET_CMOVE && !(MEM_P (operands[2]) && MEM_P (operands[3]))"
"@
cmov%O2%C1\t{%2, %k0|%k0, %2}
cmov%O2%c1\t{%3, %k0|%k0, %3}"
[(set_attr "type" "icmov")
(set_attr "mode" "SI")])
;; Don't do conditional moves with memory inputs. This splitter helps
;; register starved x86_32 by forcing inputs into registers before reload.
(define_split

10
gcc/testsuite/gcc.target/i386/cmov10.c Normal file
View file

@ -0,0 +1,10 @@
/* { dg-do compile { target { ! ia32 } } } */
/* { dg-options "-O2 -dp" } */
/* { dg-final { scan-assembler-not "zero_extendsidi" } } */
void foo (unsigned long long *d, int a, unsigned int b, unsigned int c)
{
*d = a ? b : c;
}

10
gcc/testsuite/gcc.target/i386/cmov11.c Normal file
View file

@ -0,0 +1,10 @@
/* { dg-do compile { target { ! ia32 } } } */
/* { dg-options "-O2 -dp" } */
/* { dg-final { scan-assembler-not "zero_extendsidi" } } */
unsigned long long foo (int a, unsigned b, unsigned c)
{
unsigned t = a ? b : c;
return t;
}