[Bug middle-end/50481] builtin to reverse the bit order
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50481 --- Comment #12 from Andrew Pinski --- Also will add an internal function which will be used for vectorization.
[Bug middle-end/50481] builtin to reverse the bit order
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50481
--- Comment #11 from Andrew Pinski ---
The builtins I am going to implement to be similar to clang:
__builtin_bitreverse{8,16,32,64,g}
The g one is not part of clang but will be used for _BitInt types.
[Bug middle-end/50481] builtin to reverse the bit order
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50481 Andrew Pinski changed: What|Removed |Added Assignee|unassigned at gcc dot gnu.org |pinskia at gcc dot gnu.org Keywords||missed-optimization Status|NEW |ASSIGNED --- Comment #10 from Andrew Pinski --- I am going to implement this. and add an optab too.
[Bug middle-end/50481] builtin to reverse the bit order
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50481 Xi Ruoyao changed: What|Removed |Added CC||xry111 at gcc dot gnu.org --- Comment #9 from Xi Ruoyao --- Useful for LoongArch too. And now we already have bitreverse RTX code since r14-1586.
[Bug middle-end/50481] builtin to reverse the bit order
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50481 Carlo Wood changed: What|Removed |Added CC||carlo at gcc dot gnu.org --- Comment #8 from Carlo Wood --- Bump - I need this too ;)
[Bug middle-end/50481] builtin to reverse the bit order
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50481 Frank changed: What|Removed |Added CC||f.boesing at gmx dot de --- Comment #7 from Frank --- Would be really useful to have this.
[Bug middle-end/50481] builtin to reverse the bit order
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50481 --- Comment #6 from Joseph S. Myers --- As noted in the RISC-V BoF today, this would also be useful for the RISC-V bit-manipulation extension.
[Bug middle-end/50481] builtin to reverse the bit order
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50481 Wilco changed: What|Removed |Added CC||wilco at gcc dot gnu.org --- Comment #5 from Wilco --- Yes it would be good to have a generic builtin, this issue keeps coming up: https://gcc.gnu.org/ml/gcc-patches/2019-06/msg01187.html
[Bug middle-end/50481] builtin to reverse the bit order
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50481 --- Comment #4 from krux --- +1 The builtins already produce better code than a generic bitreverse implementation: https://godbolt.org/z/Um2Tit But using special hardware instructions automatically is even more important imho.
[Bug middle-end/50481] builtin to reverse the bit order
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=50481 Matthijs van Duin changed: What|Removed |Added CC||matthijsvanduin at gmail dot com --- Comment #3 from Matthijs van Duin --- Bump! Proper intrinsics for bitreverse would be much appreciated! A plain C implementation is ugly and results in equally awful code output, while using inline asm breaks portability and can't be constant-folded or used in constexpr. What makes the continued lack of a __builtin_arm_rbit() in gcc a bit bizarre is that the (identically named) Neon versions of this instruction on AArch64 actually *did* receive proper intrinsics! [1] It's worth mentioning that clang does support __builtin_arm_rbit(), and they've actually generalized this to a full set of target-independent bitreverse builtins [2]. [1] https://gcc.gnu.org/ml/gcc-patches/2014-08/msg01913.html [2] http://clang.llvm.org/docs/LanguageExtensions.html#builtin-bitreverse
[Bug middle-end/50481] builtin to reverse the bit order
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50481 Tim Parker ptim034 at gmail dot com changed: What|Removed |Added CC||ptim034 at gmail dot com --- Comment #2 from Tim Parker ptim034 at gmail dot com 2012-03-29 10:46:11 UTC --- I totally don't understand what you talking about =_= http://www.buyanessay.com/
[Bug middle-end/50481] builtin to reverse the bit order
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50481 Jonathan Schmidt-Dominé de...@the-user.org changed: What|Removed |Added CC||de...@the-user.org --- Comment #1 from Jonathan Schmidt-Dominé de...@the-user.org 2011-09-23 15:30:33 UTC --- Informative web-page listing some methods: http://graphics.stanford.edu/~seander/bithacks.html#ReverseByteWith64BitsDiv
[Bug middle-end/50481] builtin to reverse the bit order
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50481 Paolo Carlini paolo.carlini at oracle dot com changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2011-09-22 Ever Confirmed|0 |1
