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| author | fanzha02 <fannie.zhang@arm.com> | 2021-03-23 15:35:30 +0800 |
|---|---|---|
| committer | fannie zhang <Fannie.Zhang@arm.com> | 2021-03-26 01:57:35 +0000 |
| commit | 3a0061822e0bfa79f2a464807e12970f588e3e94 (patch) | |
| tree | b96494a288bbf787aea804c13a53216b09134d88 /test/codegen | |
| parent | b587b050ca55661120912b5a1d6071a1922ad0ea (diff) | |
| download | go-3a0061822e0bfa79f2a464807e12970f588e3e94.tar.gz go-3a0061822e0bfa79f2a464807e12970f588e3e94.zip | |
cmd/compile: add arm64 rules to optimize go codes to constant 0
Optimize the following codes to constant 0.
function shift (x uint32) uint64 {
return uint64(x) >> 32
}
Change-Id: Ida6b39d713cc119ad5a2f01fd54bfd252cf2c975
Reviewed-on: https://go-review.googlesource.com/c/go/+/303830
Trust: fannie zhang <Fannie.Zhang@arm.com>
Run-TryBot: fannie zhang <Fannie.Zhang@arm.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Diffstat (limited to 'test/codegen')
| -rw-r--r-- | test/codegen/bitfield.go | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/test/codegen/bitfield.go b/test/codegen/bitfield.go index 8acefbd027..0fe6799ec1 100644 --- a/test/codegen/bitfield.go +++ b/test/codegen/bitfield.go @@ -264,3 +264,14 @@ func rev16w(c uint32) (uint32, uint32, uint32) { b3 := ((c & 0xff00ff00) >> 8) ^ ((c & 0x00ff00ff) << 8) return b1, b2, b3 } + +func shift(x uint32, y uint16, z uint8) uint64 { + // arm64:-`MOVWU`,-`LSR\t[$]32` + a := uint64(x) >> 32 + // arm64:-`MOVHU + b := uint64(y) >> 16 + // arm64:-`MOVBU` + c := uint64(z) >> 8 + // arm64:`MOVD\tZR`,-`ADD\tR[0-9]+>>16`,-`ADD\tR[0-9]+>>8`, + return a + b + c +} |