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| author | Alexandru Moșoi <mosoi@google.com> | 2016-03-24 13:40:11 +0100 |
|---|---|---|
| committer | Alexandru Moșoi <alexandru@mosoi.ro> | 2016-03-24 20:06:34 +0000 |
| commit | afafab3b9736345d150445840dbb603c883bfde4 (patch) | |
| tree | 3e93b5c13ab0bc0805865cffa17cabcd61440728 /src/encoding/json/testdata | |
| parent | d8ee180ab2722e92c568e322fbc8690688f992e3 (diff) | |
| download | go-afafab3b9736345d150445840dbb603c883bfde4.tar.xz | |
cmd/compile: simplify shifts when the counter fits 6 bits.
In f the extra & 63 is redundant because SHRQ already
looks at the bottom 6 bits only. This is a trick on AMD64
to get rid of CMPQ/SBBQ/ANDQ if one knows that the shift
counter is small.
func f(x uint64, s uint) uint64 {
return x >> (s & 63)
}
Change-Id: I4861c902168dabec9a6a14a85750246dde94fc08
Reviewed-on: https://go-review.googlesource.com/21073
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Diffstat (limited to 'src/encoding/json/testdata')
0 files changed, 0 insertions, 0 deletions