test/codegen: port floats tests to codegen

And delete them from asm_test.

Change-Id: Ibdaca3496eefc73c731b511ddb9636a1f3dff68c
Reviewed-on: https://go-review.googlesource.com/100915
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

src/cmd/compile/internal/gc/asm_test.go

@@ -410,35 +410,6 @@ var linuxAMD64Tests = []*asmTest{
 		}`,
 		pos: []string{"\tADDQ\t[A-Z]"},
 	},
-	// Floating-point strength reduction
-	{
-		fn: `
-		func f60(f float64) float64 {
-			return f * 2.0
-		}`,
-		pos: []string{"\tADDSD\t"},
-	},
-	{
-		fn: `
-		func f62(f float64) float64 {
-			return f / 16.0
-		}`,
-		pos: []string{"\tMULSD\t"},
-	},
-	{
-		fn: `
-		func f63(f float64) float64 {
-			return f / 0.125
-		}`,
-		pos: []string{"\tMULSD\t"},
-	},
-	{
-		fn: `
-		func f64(f float64) float64 {
-			return f / 0.5
-		}`,
-		pos: []string{"\tADDSD\t"},
-	},
 	// Check that compare to constant string uses 2/4/8 byte compares
 	{
 		fn: `
@@ -634,39 +605,6 @@ var linux386Tests = []*asmTest{
 }
 
 var linuxS390XTests = []*asmTest{
-	// Fused multiply-add/sub instructions.
-	{
-		fn: `
-		func f14(x, y, z float64) float64 {
-			return x * y + z
-		}
-		`,
-		pos: []string{"\tFMADD\t"},
-	},
-	{
-		fn: `
-		func f15(x, y, z float64) float64 {
-			return x * y - z
-		}
-		`,
-		pos: []string{"\tFMSUB\t"},
-	},
-	{
-		fn: `
-		func f16(x, y, z float32) float32 {
-			return x * y + z
-		}
-		`,
-		pos: []string{"\tFMADDS\t"},
-	},
-	{
-		fn: `
-		func f17(x, y, z float32) float32 {
-			return x * y - z
-		}
-		`,
-		pos: []string{"\tFMSUBS\t"},
-	},
 	{
 		// check that stack store is optimized away
 		fn: `
@@ -1113,39 +1051,6 @@ var linuxMIPS64Tests = []*asmTest{
 }
 
 var linuxPPC64LETests = []*asmTest{
-	// Fused multiply-add/sub instructions.
-	{
-		fn: `
-		func f0(x, y, z float64) float64 {
-			return x * y + z
-		}
-		`,
-		pos: []string{"\tFMADD\t"},
-	},
-	{
-		fn: `
-		func f1(x, y, z float64) float64 {
-			return x * y - z
-		}
-		`,
-		pos: []string{"\tFMSUB\t"},
-	},
-	{
-		fn: `
-		func f2(x, y, z float32) float32 {
-			return x * y + z
-		}
-		`,
-		pos: []string{"\tFMADDS\t"},
-	},
-	{
-		fn: `
-		func f3(x, y, z float32) float32 {
-			return x * y - z
-		}
-		`,
-		pos: []string{"\tFMSUBS\t"},
-	},
 	{
 		// check that stack store is optimized away
 		fn: `

test/codegen/arithmetic.go

@@ -7,7 +7,8 @@
 package codegen
 
 // This file contains codegen tests related to arithmetic
-// simplifications/optimizations.
+// simplifications and optimizations on integer types.
+// For codegen tests on float types, see floats.go.
 
 // -------------------- //
 //    Multiplication    //

test/codegen/floats.go

@@ -0,0 +1,73 @@
+// 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
+
+// This file contains codegen tests related to arithmetic
+// simplifications and optimizations on float types.
+// For codegen tests on integer types, see arithmetic.go.
+
+// --------------------- //
+//    Strength-reduce    //
+// --------------------- //
+
+func Mul2(f float64) float64 {
+	// 386:"ADDSD",-"MULSD"
+	// amd64:"ADDSD",-"MULSD"
+	// arm:"ADDD",-"MULD"
+	// arm64:"FADDD",-"FMULD"
+	return f * 2.0
+}
+
+func DivPow2(f1, f2, f3 float64) (float64, float64, float64) {
+	// 386:"MULSD",-"DIVSD"
+	// amd64:"MULSD",-"DIVSD"
+	// arm:"MULD",-"DIVD"
+	// arm64:"FMULD",-"FDIVD"
+	x := f1 / 16.0
+
+	// 386:"MULSD",-"DIVSD"
+	// amd64:"MULSD",-"DIVSD"
+	// arm:"MULD",-"DIVD"
+	// arm64:"FMULD",-"FDIVD"
+	y := f2 / 0.125
+
+	// 386:"ADDSD",-"DIVSD",-"MULSD"
+	// amd64:"ADDSD",-"DIVSD",-"MULSD"
+	// arm:"ADDD",-"MULD",-"DIVD"
+	// arm64:"FADDD",-"FMULD",-"FDIVD"
+	z := f3 / 0.5
+
+	return x, y, z
+}
+
+// ----------- //
+//    Fused    //
+// ----------- //
+
+func FusedAdd32(x, y, z float32) float32 {
+	// s390x:"FMADDS\t"
+	// ppc64le:"FMADDS\t"
+	return x*y + z
+}
+
+func FusedSub32(x, y, z float32) float32 {
+	// s390x:"FMSUBS\t"
+	// ppc64le:"FMSUBS\t"
+	return x*y - z
+}
+
+func FusedAdd64(x, y, z float64) float64 {
+	// s390x:"FMADD\t"
+	// ppc64le:"FMADD\t"
+	return x*y + z
+}
+
+func FusedSub64(x, y, z float64) float64 {
+	// s390x:"FMSUB\t"
+	// ppc64le:"FMSUB\t"
+	return x*y - z
+}