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| author | smasher164 <aindurti@gmail.com> | 2018-09-25 03:10:33 -0400 |
|---|---|---|
| committer | Keith Randall <khr@golang.org> | 2019-10-21 16:42:10 +0000 |
| commit | 7a6da218b191de13f4f3555c55aab958b09b66bd (patch) | |
| tree | 6f324979a21514735e80b78bb9ce3c5ad64ea72e /test/codegen | |
| parent | 50f4896b72d16b6538178c8ca851b20655075b7f (diff) | |
| download | go-7a6da218b191de13f4f3555c55aab958b09b66bd.tar.xz | |
cmd/compile: add fma intrinsic for amd64
To permit ssa-level optimization, this change introduces an amd64 intrinsic
that generates the VFMADD231SD instruction for the fused-multiply-add
operation on systems that support it. System support is detected via
cpu.X86.HasFMA. A rewrite rule can then translate the generic ssa intrinsic
("Fma") to VFMADD231SD.
The benchmark compares the software implementation (old) with the intrinsic
(new).
name old time/op new time/op delta
Fma-4 27.2ns ± 1% 1.0ns ± 9% -96.48% (p=0.008 n=5+5)
Updates #25819.
Change-Id: I966655e5f96817a5d06dff5942418a3915b09584
Reviewed-on: https://go-review.googlesource.com/c/go/+/137156
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'test/codegen')
| -rw-r--r-- | test/codegen/math.go | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/test/codegen/math.go b/test/codegen/math.go index 427f305c12..c942085480 100644 --- a/test/codegen/math.go +++ b/test/codegen/math.go @@ -108,6 +108,7 @@ func copysign(a, b, c float64) { } func fma(x, y, z float64) float64 { + // amd64:"VFMADD231SD" // arm64:"FMADDD" // s390x:"FMADD" // ppc64:"FMADD" |