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From: "gabravier at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/98647] New: Failure to optimize out convertion from float to vector type Date: Wed, 13 Jan 2021 00:57:05 +0000 [thread overview] Message-ID: <bug-98647-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98647 Bug ID: 98647 Summary: Failure to optimize out convertion from float to vector type Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: gabravier at gmail dot com Target Milestone: --- float f(float val) { return _mm_cvtss_f32(_mm_and_ps(_mm_set_ss(val), _mm_castsi128_ps(_mm_set1_epi32(0x7fffffff)))); } This can be optimized to avoid the conversions in the emitted assembly code. This optimization is done by LLVM, but not by GCC. LLVM code generation : .LCPI1_0: .long 0x7fffffff # float NaN .long 0x7fffffff # float NaN .long 0x7fffffff # float NaN .long 0x7fffffff # float NaN f(float): # @f(float) andps xmm0, xmmword ptr [rip + .LCPI1_0] ret GCC code generation : f(float): pxor xmm1, xmm1 movss xmm1, xmm0 movaps xmm0, XMMWORD PTR .LC1[rip] andps xmm0, xmm1 ret .LC1: .long 2147483647 .long 2147483647 .long 2147483647 .long 2147483647
next reply other threads:[~2021-01-13 0:57 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-01-13 0:57 gabravier at gmail dot com [this message] 2021-01-13 1:07 ` [Bug target/98647] " pinskia at gcc dot gnu.org 2021-01-13 1:24 ` gabravier at gmail dot com 2021-01-13 7:01 ` jakub at gcc dot gnu.org
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