build: mov deduction for booleans (#341)

Updates #336

internal/gen/mov.go

@@ -3,7 +3,6 @@ package gen
 import (
 	"errors"
 	"fmt"
-	"sort"
 	"strings"
 
 	"github.com/mmcloughlin/avo/internal/api"
@@ -48,7 +47,7 @@ func (m *mov) Generate(is []inst.Instruction) ([]byte, error) {
 }
 
 func (m *mov) instruction(i inst.Instruction) {
-	f := flags(i)
+	tcs := typecases(i)
 	mfs, err := movforms(i)
 	if err != nil {
 		m.AddError(err)
@@ -61,14 +60,12 @@ func (m *mov) instruction(i inst.Instruction) {
 			fmt.Sprintf("bn == %d", opsize[mf.B]),
 			fmt.Sprintf("%s(b)", api.CheckerName(mf.B)),
 		}
-		for c, on := range f {
-			cmp := map[bool]string{true: "!=", false: "=="}
-			cond := fmt.Sprintf("(t.Info() & %s) %s 0", c, cmp[on])
-			conds = append(conds, cond)
+
+		for _, tc := range tcs {
+			typecase := fmt.Sprintf("(t.Info() & %s) %s %s", tc.Mask, tc.Op, tc.Value)
+			m.Printf("case %s && %s:\n", strings.Join(conds, " && "), typecase)
+			m.Printf("c.%s(a, b)\n", i.Opcode)
 		}
-		sort.Strings(conds)
-		m.Printf("case %s:\n", strings.Join(conds, " && "))
-		m.Printf("c.%s(a, b)\n", i.Opcode)
 	}
 }
 
@@ -100,21 +97,32 @@ func ismov(i inst.Instruction) bool {
 	return true
 }
 
-func flags(i inst.Instruction) map[string]bool {
-	f := map[string]bool{}
+type typecase struct {
+	Mask  string
+	Op    string
+	Value string
+}
+
+func typecases(i inst.Instruction) []typecase {
 	switch {
 	case strings.Contains(i.Summary, "Floating-Point"):
-		f["types.IsFloat"] = true
+		return []typecase{
+			{"types.IsFloat", "!=", "0"},
+		}
 	case strings.Contains(i.Summary, "Zero-Extend"):
-		f["types.IsInteger"] = true
-		f["types.IsUnsigned"] = true
+		return []typecase{
+			{"(types.IsInteger|types.IsUnsigned)", "==", "(types.IsInteger|types.IsUnsigned)"},
+			{"types.IsBoolean", "!=", "0"},
+		}
 	case strings.Contains(i.Summary, "Sign-Extension"):
-		f["types.IsInteger"] = true
-		f["types.IsUnsigned"] = false
+		return []typecase{
+			{"(types.IsInteger|types.IsUnsigned)", "==", "types.IsInteger"},
+		}
 	default:
-		f["types.IsInteger"] = true
+		return []typecase{
+			{"(types.IsInteger|types.IsBoolean)", "!=", "0"},
+		}
 	}
-	return f
 }
 
 type movform struct{ A, B string }

tests/fixedbugs/issue336/asm.go

@@ -0,0 +1,38 @@
+//go:build ignore
+// +build ignore
+
+package main
+
+import (
+	"fmt"
+
+	. "github.com/mmcloughlin/avo/build"
+	. "github.com/mmcloughlin/avo/operand"
+	. "github.com/mmcloughlin/avo/reg"
+)
+
+func main() {
+	variants := []struct {
+		Size     int
+		Register func() GPVirtual
+		XOR      func(Op, Op)
+	}{
+		{8, GP8L, XORB},
+		{16, GP16, XORW},
+		{32, GP32, XORL},
+		{64, GP64, XORQ},
+	}
+
+	for _, v := range variants {
+		name := fmt.Sprintf("Not%d", v.Size)
+		TEXT(name, NOSPLIT, "func(x bool) bool")
+		Doc(fmt.Sprintf("%s returns the boolean negation of x using a %d-bit intermediate.", name, v.Size))
+		x := v.Register()
+		Load(Param("x"), x)
+		v.XOR(U8(1), x)
+		Store(x.As8L(), ReturnIndex(0))
+		RET()
+	}
+
+	Generate()
+}

tests/fixedbugs/issue336/doc.go

@@ -0,0 +1,4 @@
+// Package issue336 tests boolean arguments and return values.
+//
+// Issue #336 pointed out that move deduction for boolean types was not present.
+package issue336

tests/fixedbugs/issue336/issue336.s

@@ -0,0 +1,31 @@
+// Code generated by command: go run asm.go -out issue336.s -stubs stub.go. DO NOT EDIT.
+
+#include "textflag.h"
+
+// func Not8(x bool) bool
+TEXT ·Not8(SB), NOSPLIT, $0-9
+	MOVB x+0(FP), AL
+	XORB $0x01, AL
+	MOVB AL, ret+8(FP)
+	RET
+
+// func Not16(x bool) bool
+TEXT ·Not16(SB), NOSPLIT, $0-9
+	MOVBWZX x+0(FP), AX
+	XORW    $0x01, AX
+	MOVB    AL, ret+8(FP)
+	RET
+
+// func Not32(x bool) bool
+TEXT ·Not32(SB), NOSPLIT, $0-9
+	MOVBLZX x+0(FP), AX
+	XORL    $0x01, AX
+	MOVB    AL, ret+8(FP)
+	RET
+
+// func Not64(x bool) bool
+TEXT ·Not64(SB), NOSPLIT, $0-9
+	MOVBQZX x+0(FP), AX
+	XORQ    $0x01, AX
+	MOVB    AL, ret+8(FP)
+	RET

tests/fixedbugs/issue336/issue336_test.go

@@ -0,0 +1,16 @@
+package issue336
+
+import "testing"
+
+//go:generate go run asm.go -out issue336.s -stubs stub.go
+
+func TestNot(t *testing.T) {
+	nots := []func(bool) bool{Not8, Not16, Not32, Not64}
+	for _, not := range nots {
+		for _, x := range []bool{true, false} {
+			if not(x) != !x {
+				t.Fail()
+			}
+		}
+	}
+}