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95c4f320d5
Adds rules that rewrites statements such as ~P&~Q as ~(P|Q) and ~P|~Q as ~(P&Q), removing an extraneous instruction.
Change-Id: Icedb97df741680ddf9799df79df78657173aa500
GitHub-Last-Rev: f22e2350c9
GitHub-Pull-Request: golang/go#60018
Reviewed-on: https://go-review.googlesource.com/c/go/+/493175
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Stefan M <st3f4nm4d4@gmail.com>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
41 lines
1.1 KiB
Go
41 lines
1.1 KiB
Go
// asmcheck
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// Copyright 2018 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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// Test to make sure that (CMPQ (ANDQ x y) [0]) does not get rewritten to
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// (TESTQ x y) if the ANDQ has other uses. If that rewrite happens, then one
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// of the args of the ANDQ needs to be saved so it can be used as the arg to TESTQ.
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func andWithUse(x, y int) int {
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z := x & y
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// amd64:`TESTQ\s(AX, AX|BX, BX|CX, CX|DX, DX|SI, SI|DI, DI|R8, R8|R9, R9|R10, R10|R11, R11|R12, R12|R13, R13|R15, R15)`
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if z == 0 {
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return 77
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}
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// use z by returning it
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return z
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}
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// Verify (OR x (NOT y)) rewrites to (ORN x y) where supported
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func ornot(x, y int) int {
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// ppc64x:"ORN"
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z := x | ^y
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return z
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}
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// Verify that (OR (NOT x) (NOT y)) rewrites to (NOT (AND x y))
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func orDemorgans(x, y int) int {
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// amd64:"AND",-"OR"
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z := ^x | ^y
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return z
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}
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// Verify that (AND (NOT x) (NOT y)) rewrites to (NOT (OR x y))
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func andDemorgans(x, y int) int {
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// amd64:"OR",-"AND"
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z := ^x & ^y
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return z
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}
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