go/test/inline_math_bits_rotate.go
Andrew Bonventre 5ac2476748 cmd/compile: make math/bits.RotateLeft* an intrinsic on amd64
Previously, pattern matching was good enough to achieve good performance
for the RotateLeft* functions, but the inlining cost for them was much
too high. Make RotateLeft* intrinsic on amd64 as a stop-gap for now to
reduce inlining costs.

This should be done (or at least looked at) for other architectures
as well.

Updates golang/go#17566

Change-Id: I6a106ff00b6c4e3f490650af3e083ed2be00c819
Reviewed-on: https://go-review.googlesource.com/132435
Run-TryBot: Andrew Bonventre <andybons@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2018-08-30 22:48:28 +00:00

28 lines
569 B
Go

// +build amd64
// errorcheck -0 -m
// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Test that inlining of math/bits.RotateLeft* treats those calls as intrinsics.
package p
import "math/bits"
var (
x8 uint8
x16 uint16
x32 uint32
x64 uint64
x uint
)
func f() { // ERROR "can inline f"
x8 = bits.RotateLeft8(x8, 1)
x16 = bits.RotateLeft16(x16, 1)
x32 = bits.RotateLeft32(x32, 1)
x64 = bits.RotateLeft64(x64, 1)
x = bits.RotateLeft(x, 1)
}