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https://github.com/golang/go
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9a19481acb
Current many architectures use a rule along the lines of // Canonicalize the order of arguments to comparisons - helps with CSE. ((CMP|CMPW) x y) && x.ID > y.ID => (InvertFlags ((CMP|CMPW) y x)) to normalize comparisons as much as possible for CSE. Replace the ID comparison with something less variable across compiler changes. This helps avoid spurious failures in some of the codegen-comparison tests (though the current choice of comparison is sensitive to Op ordering). Two tests changed to accommodate modified instruction choice. Change-Id: Ib35f450bd2bae9d4f9f7838ceaf7ec682bcf1e1a Reviewed-on: https://go-review.googlesource.com/c/go/+/280155 Trust: David Chase <drchase@google.com> Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
39 lines
722 B
Go
39 lines
722 B
Go
// +build amd64
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// asmcheck -gcflags=-spectre=index
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// Copyright 2020 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package codegen
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func IndexArray(x *[10]int, i int) int {
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// amd64:`CMOVQCC`
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return x[i]
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}
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func IndexString(x string, i int) byte {
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// amd64:`CMOVQLS`
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return x[i]
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}
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func IndexSlice(x []float64, i int) float64 {
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// amd64:`CMOVQLS`
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return x[i]
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}
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func SliceArray(x *[10]int, i, j int) []int {
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// amd64:`CMOVQHI`
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return x[i:j]
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}
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func SliceString(x string, i, j int) string {
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// amd64:`CMOVQHI`
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return x[i:j]
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}
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func SliceSlice(x []float64, i, j int) []float64 {
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// amd64:`CMOVQHI`
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return x[i:j]
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}
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