https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101989
Bug ID: 101989
Summary: Fail to optimize (a & b) | (c & ~b) to vpternlog
instruction.
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: crazylht at gmail dot com
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Target: x86_64-*-* i?86-*-*
cat test.c
__m128i foo (__m128i src1, __m128i src2, __m128i src3)
{
return (src2 & ~src1) | (src3 & src1);
}
__m128i foo1 (__m128i src1, __m128i src2, __m128i src3)
{
return (src2 & src1) | (src3 & ~src1);
}
gcc -O2 -march=cascadelake generates
foo(long long __vector(2), long long __vector(2), long long __vector(2)):
vpxor %xmm2, %xmm1, %xmm2
vpand %xmm0, %xmm2, %xmm2
vpxor %xmm1, %xmm2, %xmm0
ret
foo1(long long __vector(2), long long __vector(2), long long __vector(2)):
vpxor %xmm2, %xmm1, %xmm1
vpand %xmm0, %xmm1, %xmm1
vpxor %xmm2, %xmm1, %xmm0
ret
icx generates
foo(long long __vector(2), long long __vector(2), long long __vector(2)):
#
vpternlogq xmm0, xmm2, xmm1, 202
ret
foo1(long long __vector(2), long long __vector(2), long long __vector(2)):
#
vpternlogq xmm0, xmm1, xmm2, 202
ret
Guess we need a post_reload splitter to match
Failed to match this instruction:
(set (reg:V2DI 88)
(xor:V2DI (and:V2DI (xor:V2DI (reg:V2DI 92)
(reg/v:V2DI 87 [ src3 ]))
(reg:V2DI 91))
(reg/v:V2DI 87 [ src3 ])))
Failed to match this instruction:
