https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105791
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Roger Sayle <sa...@gcc.gnu.org>: https://gcc.gnu.org/g:c4320bde42c6497b701e2e6b8f1c5069bed19818 commit r13-998-gc4320bde42c6497b701e2e6b8f1c5069bed19818 Author: Roger Sayle <ro...@nextmovesoftware.com> Date: Tue Jun 7 07:49:40 2022 +0100 Recognize vpcmov in combine with -mxop on x86. By way of an apology for causing PR target/105791, where I'd overlooked the need to support V1TImode in TARGET_XOP's vpcmov instruction, this patch further improves support for TARGET_XOP's vpcmov instruction, by recognizing it in combine. Currently, the test case: typedef int v4si __attribute__ ((vector_size (16))); v4si foo(v4si c, v4si t, v4si f) { return (c&t)|(~c&f); } on x86_64 with -O2 -mxop generates: vpxor %xmm2, %xmm1, %xmm1 vpand %xmm0, %xmm1, %xmm1 vpxor %xmm2, %xmm1, %xmm0 ret but with this patch now generates: vpcmov %xmm0, %xmm2, %xmm1, %xmm0 ret On its own, the new combine splitter works fine on TARGET_64BIT, but alas with -m32 combine incorrectly thinks the replacement instruction is more expensive, as IF_THEN_ELSE isn't currently/correctly handled in ix86_rtx_costs. So to avoid the need for a target selector in the new tescase, I've updated ix86_rtx_costs to report that AMD's vpcmov has a latency of two cycles [it's now an obsolete instruction set extension and there's unlikely to ever be a processor where this instruction has a different timing], and while there I also added rtx_costs for x86_64's integer conditional move instructions (which have single cycle latency). 2022-06-07 Roger Sayle <ro...@nextmovesoftware.com> gcc/ChangeLog * config/i386/i386.cc (ix86_rtx_costs): Add a new case for IF_THEN_ELSE, and provide costs for TARGET_XOP's vpcmov and TARGET_CMOVE's (scalar integer) conditional moves. * config/i386/sse.md (define_split): Recognize XOP's vpcmov from its equivalent (canonical) pxor;pand;pxor sequence. gcc/testsuite/ChangeLog * gcc.target/i386/xop-pcmov3.c: New test case.
