test/codegen: port comparisons tests to codegen

And delete them from asm_test.

Change-Id: I64c512bfef3b3da6db5c5d29277675dade28b8ab
Reviewed-on: https://go-review.googlesource.com/101595
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Giovanni Bajo <rasky@develer.com>

test/codegen/comparisons.go

@@ -0,0 +1,69 @@
+// asmcheck
+
+// 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.
+
+package codegen
+
+import "unsafe"
+
+// This file contains code generation tests related to the comparison
+// operators.
+
+// -------------- //
+//    Equality    //
+// -------------- //
+
+// Check that compare to constant string use 2/4/8 byte compares
+
+func CompareString1(s string) bool {
+	// amd64:`CMPW\t\(.*\), [$]`
+	return s == "xx"
+}
+
+func CompareString2(s string) bool {
+	// amd64:`CMPL\t\(.*\), [$]`
+	return s == "xxxx"
+}
+
+func CompareString3(s string) bool {
+	// amd64:`CMPQ\t\(.*\), [A-Z]`
+	return s == "xxxxxxxx"
+}
+
+// Check that arrays compare use 2/4/8 byte compares
+
+func CompareArray1(a, b [2]byte) bool {
+	// amd64:`CMPW\t""[.+_a-z0-9]+\(SP\), [A-Z]`
+	return a == b
+}
+
+func CompareArray2(a, b [3]uint16) bool {
+	// amd64:`CMPL\t""[.+_a-z0-9]+\(SP\), [A-Z]`
+	// amd64:`CMPW\t""[.+_a-z0-9]+\(SP\), [A-Z]`
+	return a == b
+}
+
+func CompareArray3(a, b [3]int16) bool {
+	// amd64:`CMPL\t""[.+_a-z0-9]+\(SP\), [A-Z]`
+	// amd64:`CMPW\t""[.+_a-z0-9]+\(SP\), [A-Z]`
+	return a == b
+}
+
+func CompareArray4(a, b [12]int8) bool {
+	// amd64:`CMPQ\t""[.+_a-z0-9]+\(SP\), [A-Z]`
+	// amd64:`CMPL\t""[.+_a-z0-9]+\(SP\), [A-Z]`
+	return a == b
+}
+
+func CompareArray5(a, b [15]byte) bool {
+	// amd64:`CMPQ\t""[.+_a-z0-9]+\(SP\), [A-Z]`
+	return a == b
+}
+
+// This was a TODO in mapaccess1_faststr
+func CompareArray6(a, b unsafe.Pointer) bool {
+	// amd64:`CMPL\t\(.*\), [A-Z]`
+	return *((*[4]byte)(a)) != *((*[4]byte)(b))
+}