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| author | Cherry Mui <cherryyz@google.com> | 2022-08-22 17:00:17 -0400 |
|---|---|---|
| committer | Cherry Mui <cherryyz@google.com> | 2022-08-22 21:29:31 +0000 |
| commit | 8bf9e014736064de436c411a95467b583f430dea (patch) | |
| tree | 27bc8c1f18d0b9f11999afb8354c068ea7559af9 /test/codegen/mathbits.go | |
| parent | 48da729e8468b630ee003ac51cbaac595d53bec8 (diff) | |
| download | go-8bf9e014736064de436c411a95467b583f430dea.tar.xz | |
cmd/compile: split Muluhilo op on ARM64
On ARM64 we use two separate instructions to compute the hi and lo
results of a 64x64->128 multiplication. Lower to two separate ops
so if only one result is needed we can deadcode the other.
Fixes #54607.
Change-Id: Ib023e77eb2b2b0bcf467b45471cb8a294bce6f90
Reviewed-on: https://go-review.googlesource.com/c/go/+/425101
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Diffstat (limited to 'test/codegen/mathbits.go')
| -rw-r--r-- | test/codegen/mathbits.go | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/test/codegen/mathbits.go b/test/codegen/mathbits.go index fe9c4eceb5..20c945fbc3 100644 --- a/test/codegen/mathbits.go +++ b/test/codegen/mathbits.go @@ -798,6 +798,18 @@ func Mul64(x, y uint64) (hi, lo uint64) { return bits.Mul64(x, y) } +func Mul64HiOnly(x, y uint64) uint64 { + // arm64:"UMULH",-"MUL" + hi, _ := bits.Mul64(x, y) + return hi +} + +func Mul64LoOnly(x, y uint64) uint64 { + // arm64:"MUL",-"UMULH" + _, lo := bits.Mul64(x, y) + return lo +} + // --------------- // // bits.Div* // // --------------- // |