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| author | Rémy Oudompheng <oudomphe@phare.normalesup.org> | 2013-07-31 23:37:23 +0200 |
|---|---|---|
| committer | Rémy Oudompheng <oudomphe@phare.normalesup.org> | 2013-07-31 23:37:23 +0200 |
| commit | a05237f20ae6230238a9e44bc8bfc974e6d51422 (patch) | |
| tree | 3e1c0471fb6cecaebfab10d9bd70c6907bc350bf /src/pkg/runtime/runtime.c | |
| parent | 727901410a9394b5c6d8f844321eb651cfa4abca (diff) | |
| download | go-a05237f20ae6230238a9e44bc8bfc974e6d51422.tar.xz | |
runtime: save 8 stack bytes in timediv on arm.
Operations on int64 are very stack consuming with 5c.
Fixes netbsd/arm build.
Before: TEXT runtime.timediv+0(SB),7,$52-16
After: TEXT runtime.timediv+0(SB),7,$44-16
The stack usage is unchanged on 386:
TEXT runtime.timediv+0(SB),7,$8-16
R=golang-dev, dvyukov, bradfitz
CC=golang-dev
https://golang.org/cl/12182044
Diffstat (limited to 'src/pkg/runtime/runtime.c')
| -rw-r--r-- | src/pkg/runtime/runtime.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/src/pkg/runtime/runtime.c b/src/pkg/runtime/runtime.c index 5bca6f87b4..a0e9a194c6 100644 --- a/src/pkg/runtime/runtime.c +++ b/src/pkg/runtime/runtime.c @@ -421,16 +421,16 @@ runtime·timediv(int64 v, int32 div, int32 *rem) { int32 res, bit; - if(v >= div*0x7fffffffLL) { + if(v >= (int64)div*0x7fffffffLL) { if(rem != nil) *rem = 0; return 0x7fffffff; } res = 0; - for(bit = 0x40000000; bit != 0; bit >>= 1) { - if(v >= (int64)bit*div) { - v = v - (int64)bit*div; - res += bit; + for(bit = 30; bit >= 0; bit--) { + if(v >= ((int64)div<<bit)) { + v = v - ((int64)div<<bit); + res += 1<<bit; } } if(rem != nil) |