parameter loading

internal/gen/mov.go

@@ -0,0 +1,138 @@
+package gen
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/mmcloughlin/avo/internal/inst"
+)
+
+type mov struct {
+	cfg Config
+	generator
+}
+
+func NewMOV(cfg Config) Interface {
+	return GoFmt(&mov{cfg: cfg})
+}
+
+func (m *mov) Generate(is []inst.Instruction) ([]byte, error) {
+	m.Printf("// %s\n\n", m.cfg.GeneratedWarning())
+	m.Printf("package build\n\n")
+
+	m.Printf("import (\n")
+	m.Printf("\t\"go/types\"\n")
+	m.Printf("\t\"%s/operand\"\n", pkg)
+	m.Printf(")\n\n")
+
+	m.Printf("func (c *Context) mov(a, b operand.Op, an, bn int, t *types.Basic) {\n")
+	m.Printf("switch {\n")
+	for _, i := range is {
+		if ismov(i) {
+			m.instruction(i)
+		}
+	}
+	m.Printf("default:\n")
+	m.Printf("c.AddErrorMessage(\"could not deduce mov instruction\")\n")
+	m.Printf("}\n")
+	m.Printf("}\n")
+	return m.Result()
+}
+
+func (m *mov) instruction(i inst.Instruction) {
+	f := flags(i)
+	sizes, err := formsizes(i)
+	if err != nil {
+		m.AddError(err)
+		return
+	}
+	for _, size := range sizes {
+		conds := []string{
+			fmt.Sprintf("an == %d", size.A),
+			fmt.Sprintf("bn == %d", size.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)
+		}
+		m.Printf("case %s:\n", strings.Join(conds, " && "))
+		m.Printf("c.%s(a, b)\n", i.Opcode)
+	}
+}
+
+// ismov decides whether the given instruction is a plain move instruction.
+func ismov(i inst.Instruction) bool {
+	if i.AliasOf != "" || !strings.HasPrefix(i.Opcode, "MOV") {
+		return false
+	}
+	exclude := []string{"Packed", "Duplicate", "Aligned", "Hint", "Swapping"}
+	for _, substring := range exclude {
+		if strings.Contains(i.Summary, substring) {
+			return false
+		}
+	}
+	return true
+}
+
+func flags(i inst.Instruction) map[string]bool {
+	f := map[string]bool{}
+	switch {
+	case strings.Contains(i.Summary, "Floating-Point"):
+		f["types.IsFloat"] = true
+	case strings.Contains(i.Summary, "Zero-Extend"):
+		f["types.IsInteger"] = true
+		f["types.IsUnsigned"] = true
+	case strings.Contains(i.Summary, "Sign-Extension"):
+		f["types.IsInteger"] = true
+		f["types.IsUnsigned"] = false
+	default:
+		f["types.IsInteger"] = true
+	}
+	return f
+}
+
+type movsize struct{ A, B int }
+
+func formsizes(i inst.Instruction) ([]movsize, error) {
+	set := map[movsize]bool{}
+	for _, f := range i.Forms {
+		if f.Arity() != 2 {
+			continue
+		}
+		s := movsize{
+			A: opsize[f.Operands[0].Type],
+			B: opsize[f.Operands[1].Type],
+		}
+		if s.A < 0 || s.B < 0 {
+			continue
+		}
+		if s.A == 0 || s.B == 0 {
+			return nil, errors.New("unknown operand type")
+		}
+		set[s] = true
+	}
+	var ss []movsize
+	for s := range set {
+		ss = append(ss, s)
+	}
+	return ss, nil
+}
+
+var opsize = map[string]int{
+	"imm8":  -1,
+	"imm16": -1,
+	"imm32": -1,
+	"imm64": -1,
+	"r8":    1,
+	"r16":   2,
+	"r32":   4,
+	"r64":   8,
+	"xmm":   16,
+	"m8":    1,
+	"m16":   2,
+	"m32":   4,
+	"m64":   8,
+	"m128":  16,
+}