| Message ID | 20231017140706.21281-1-xry111@xry111.site |
|---|---|
| State | New |
| Headers | show |
| Series | LoongArch: Use fcmp.caf.s instead of movgr2cf for zeroing a fcc | expand |
On 10/17/23 22:06, Xi Ruoyao wrote: > During the review of a LLVM change [1], on LA464 we found that zeroing "an" LLVM change (because the word LLVM is pronounced letter-by-letter) > a fcc with fcmp.caf.s is much faster than a movgr2cf from $r0. Similarly, "an" fcc > > [1]: https://github.com/llvm/llvm-project/pull/69300 > > gcc/ChangeLog: > > * config/loongarch/loongarch.md (movfcc): Use fcmp.caf.s for > zeroing a fcc. > --- > > Bootstrapped and regtested on loongarch64-linux-gnu. Ok for trunk? > > gcc/config/loongarch/loongarch.md | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/gcc/config/loongarch/loongarch.md b/gcc/config/loongarch/loongarch.md > index 68897799505..743e75907a6 100644 > --- a/gcc/config/loongarch/loongarch.md > +++ b/gcc/config/loongarch/loongarch.md > @@ -2151,7 +2151,7 @@ (define_insn "movfcc" > [(set (match_operand:FCC 0 "register_operand" "=z") > (const_int 0))] > "" > - "movgr2cf\t%0,$r0") > + "fcmp.caf.s\t%0,$f0,$f0") > > ;; Conditional move instructions. > Trivial enough, so this LGTM apart from the grammatical nits. (Whoever pushing this patch could simply amend it themselves so maybe there's no need for a v2.) Thanks!
在 2023/10/17 下午10:24, WANG Xuerui 写道: > > On 10/17/23 22:06, Xi Ruoyao wrote: >> During the review of a LLVM change [1], on LA464 we found that zeroing > "an" LLVM change (because the word LLVM is pronounced letter-by-letter) >> a fcc with fcmp.caf.s is much faster than a movgr2cf from $r0. > Similarly, "an" fcc >> >> [1]: https://github.com/llvm/llvm-project/pull/69300 >> >> gcc/ChangeLog: >> >> * config/loongarch/loongarch.md (movfcc): Use fcmp.caf.s for >> zeroing a fcc. >> --- >> >> Bootstrapped and regtested on loongarch64-linux-gnu. Ok for trunk? Ok! Thanks. >> >> gcc/config/loongarch/loongarch.md | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/gcc/config/loongarch/loongarch.md >> b/gcc/config/loongarch/loongarch.md >> index 68897799505..743e75907a6 100644 >> --- a/gcc/config/loongarch/loongarch.md >> +++ b/gcc/config/loongarch/loongarch.md >> @@ -2151,7 +2151,7 @@ (define_insn "movfcc" >> [(set (match_operand:FCC 0 "register_operand" "=z") >> (const_int 0))] >> "" >> - "movgr2cf\t%0,$r0") >> + "fcmp.caf.s\t%0,$f0,$f0") >> ;; Conditional move instructions. > Trivial enough, so this LGTM apart from the grammatical nits. (Whoever > pushing this patch could simply amend it themselves so maybe there's > no need for a v2.) Thanks! \
On Wed, 2023-10-18 at 09:34 +0800, chenglulu wrote: > > 在 2023/10/17 下午10:24, WANG Xuerui 写道: > > > > On 10/17/23 22:06, Xi Ruoyao wrote: > > > During the review of a LLVM change [1], on LA464 we found that zeroing > > "an" LLVM change (because the word LLVM is pronounced letter-by-letter) > > > a fcc with fcmp.caf.s is much faster than a movgr2cf from $r0. > > Similarly, "an" fcc > > > > > > [1]: https://github.com/llvm/llvm-project/pull/69300 > > > > > > gcc/ChangeLog: > > > > > > * config/loongarch/loongarch.md (movfcc): Use fcmp.caf.s for > > > zeroing a fcc. > > > --- > > > > > > Bootstrapped and regtested on loongarch64-linux-gnu. Ok for trunk? > > Ok! Pushed r14-4712 with the commit message modified following Xuerui's suggestion.
diff --git a/gcc/config/loongarch/loongarch.md b/gcc/config/loongarch/loongarch.md index 68897799505..743e75907a6 100644 --- a/gcc/config/loongarch/loongarch.md +++ b/gcc/config/loongarch/loongarch.md @@ -2151,7 +2151,7 @@ (define_insn "movfcc" [(set (match_operand:FCC 0 "register_operand" "=z") (const_int 0))] "" - "movgr2cf\t%0,$r0") + "fcmp.caf.s\t%0,$f0,$f0") ;; Conditional move instructions.