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* [Bug tree-optimization/101116] New: missed peephole optimization not of bitwise and @ 2021-06-18 5:17 hiraditya at msn dot com 2021-06-18 5:35 ` [Bug target/101116] " pinskia at gcc dot gnu.org 2021-06-18 5:42 ` pinskia at gcc dot gnu.org 0 siblings, 2 replies; 3+ messages in thread From: hiraditya at msn dot com @ 2021-06-18 5:17 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101116 Bug ID: 101116 Summary: missed peephole optimization not of bitwise and Product: gcc Version: 11.1.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: hiraditya at msn dot com Target Milestone: --- $ cat test.c bool foo(unsigned i) { return !(i & 1); } gcc -O2 test.c -S -o- foo(unsigned int): mov eax, edi not eax and eax, 1 ret clang -O2 test.c -S -o- foo(unsigned int): # @foo(unsigned int) testb $1, %dil sete %al retq Ref: https://godbolt.org/z/Tndb1dM8Y ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug target/101116] missed peephole optimization not of bitwise and 2021-06-18 5:17 [Bug tree-optimization/101116] New: missed peephole optimization not of bitwise and hiraditya at msn dot com @ 2021-06-18 5:35 ` pinskia at gcc dot gnu.org 2021-06-18 5:42 ` pinskia at gcc dot gnu.org 1 sibling, 0 replies; 3+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-06-18 5:35 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101116 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Component|tree-optimization |target --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- It is an open question which is better. ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug target/101116] missed peephole optimization not of bitwise and 2021-06-18 5:17 [Bug tree-optimization/101116] New: missed peephole optimization not of bitwise and hiraditya at msn dot com 2021-06-18 5:35 ` [Bug target/101116] " pinskia at gcc dot gnu.org @ 2021-06-18 5:42 ` pinskia at gcc dot gnu.org 1 sibling, 0 replies; 3+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-06-18 5:42 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101116 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Take: unsigned char foo(unsigned *i) { return !(*i & 1); } GCC and clang/LLVM produce similar code. In fact similar to what GCC produces before. Note also ICC produces the same code as GCC for original case. So does Microsoft compiler. So I think we can say this is not a missed optimization for GCC. ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-06-18 5:42 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-06-18 5:17 [Bug tree-optimization/101116] New: missed peephole optimization not of bitwise and hiraditya at msn dot com 2021-06-18 5:35 ` [Bug target/101116] " pinskia at gcc dot gnu.org 2021-06-18 5:42 ` pinskia at gcc dot gnu.org
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