logic.go

     1  // asmcheck
     2  
     3  // Copyright 2018 The Go Authors. All rights reserved.
     4  // Use of this source code is governed by a BSD-style
     5  // license that can be found in the LICENSE file.
     6  
     7  package codegen
     8  
     9  var gx, gy int
    10  
    11  // Test to make sure that (CMPQ (ANDQ x y) [0]) does not get rewritten to
    12  // (TESTQ x y) if the ANDQ has other uses. If that rewrite happens, then one
    13  // of the args of the ANDQ needs to be saved so it can be used as the arg to TESTQ.
    14  func andWithUse(x, y int) int {
    15  	// Load x,y into registers, so those MOVQ will not appear at the z := x&y line.
    16  	gx, gy = x, y
    17  	// amd64:-"MOVQ"
    18  	z := x & y
    19  	if z == 0 {
    20  		return 77
    21  	}
    22  	// use z by returning it
    23  	return z
    24  }
    25  
    26  // Verify (OR x (NOT y)) rewrites to (ORN x y) where supported
    27  func ornot(x, y int) int {
    28  	// ppc64:"ORN"
    29  	// ppc64le:"ORN"
    30  	z := x | ^y
    31  	return z
    32  }
    33
View as plain text