cmd/compile/internal/ir: add Type param to NewBasicLit

This CL adds an explicit Type parameter to NewBasicLit so that callers
can directly construct typed OLITERAL nodes.

Change-Id: I0ab50ac3d7ddb7adcc903633a62ac496921165e9
Reviewed-on: https://go-review.googlesource.com/c/go/+/527096
Auto-Submit: Matthew Dempsky <mdempsky@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>

5 files changed, 38 insertions, 18 deletions

diff --git a/src/cmd/compile/internal/ir/const.go b/src/cmd/compile/internal/ir/const.go
index 751620f26a..74e55511e4 100644
--- a/src/cmd/compile/internal/ir/const.go
+++ b/src/cmd/compile/internal/ir/const.go
@@ -14,18 +14,44 @@ import (
 	"cmd/internal/src"
 )
 
+// NewBool returns an OLITERAL representing b as an untyped boolean.
 func NewBool(pos src.XPos, b bool) Node {
-	return NewBasicLit(pos, constant.MakeBool(b))
+	return NewBasicLit(pos, types.UntypedBool, constant.MakeBool(b))
 }
 
+// NewInt returns an OLITERAL representing v as an untyped integer.
 func NewInt(pos src.XPos, v int64) Node {
-	return NewBasicLit(pos, constant.MakeInt64(v))
+	return NewBasicLit(pos, types.UntypedInt, constant.MakeInt64(v))
 }
 
+// NewString returns an OLITERAL representing s as an untyped string.
 func NewString(pos src.XPos, s string) Node {
-	return NewBasicLit(pos, constant.MakeString(s))
+	return NewBasicLit(pos, types.UntypedString, constant.MakeString(s))
 }
 
+// NewOne returns an OLITERAL representing 1 with the given type.
+func NewOne(pos src.XPos, typ *types.Type) Node {
+	var val constant.Value
+	switch {
+	case typ.IsInteger():
+		val = intOne
+	case typ.IsFloat():
+		val = floatOne
+	case typ.IsComplex():
+		val = complexOne
+	default:
+		base.FatalfAt(pos, "%v cannot represent 1", typ)
+	}
+
+	return NewBasicLit(pos, typ, val)
+}
+
+var (
+	intOne     = constant.MakeInt64(1)
+	floatOne   = constant.ToFloat(intOne)
+	complexOne = constant.ToComplex(intOne)
+)
+
 const (
 	// Maximum size in bits for big.Ints before signaling
 	// overflow and also mantissa precision for big.Floats.
diff --git a/src/cmd/compile/internal/ir/expr.go b/src/cmd/compile/internal/ir/expr.go
index abea185dd3..676045d27a 100644
--- a/src/cmd/compile/internal/ir/expr.go
+++ b/src/cmd/compile/internal/ir/expr.go
@@ -132,15 +132,14 @@ type BasicLit struct {
 	val constant.Value
 }
 
-func NewBasicLit(pos src.XPos, val constant.Value) Node {
-	if val == nil || val.Kind() == constant.Unknown {
-		base.FatalfAt(pos, "bad value: %v", val)
-	}
+// NewBasicLit returns an OLITERAL representing val with the given type.
+func NewBasicLit(pos src.XPos, typ *types.Type, val constant.Value) Node {
+	AssertValidTypeForConst(typ, val)
 
 	n := &BasicLit{val: val}
 	n.op = OLITERAL
 	n.pos = pos
-	n.SetType(types.UntypedTypes[val.Kind()])
+	n.SetType(typ)
 	n.SetTypecheck(1)
 	return n
 }
@@ -151,10 +150,7 @@ func (n *BasicLit) SetVal(val constant.Value) { n.val = val }
 // NewConstExpr returns an OLITERAL representing val, copying the
 // position and type from orig.
 func NewConstExpr(val constant.Value, orig Node) Node {
-	n := NewBasicLit(orig.Pos(), val)
-	n.SetType(orig.Type())
-	n.SetTypecheck(orig.Typecheck())
-	return n
+	return NewBasicLit(orig.Pos(), orig.Type(), val)
 }
 
 // A BinaryExpr is a binary expression X Op Y,
diff --git a/src/cmd/compile/internal/noder/helpers.go b/src/cmd/compile/internal/noder/helpers.go
index ae31f86006..05a57d07f0 100644
--- a/src/cmd/compile/internal/noder/helpers.go
+++ b/src/cmd/compile/internal/noder/helpers.go
@@ -79,8 +79,6 @@ func Deref(pos src.XPos, typ *types.Type, x ir.Node) *ir.StarExpr {
 
 // Statements
 
-var one = constant.MakeInt64(1)
-
 func idealType(tv syntax.TypeAndValue) types2.Type {
 	// The gc backend expects all expressions to have a concrete type, and
 	// types2 mostly satisfies this expectation already. But there are a few
diff --git a/src/cmd/compile/internal/noder/reader.go b/src/cmd/compile/internal/noder/reader.go
index 35dfe3d674..4b26eb4668 100644
--- a/src/cmd/compile/internal/noder/reader.go
+++ b/src/cmd/compile/internal/noder/reader.go
@@ -1760,7 +1760,7 @@ func (r *reader) stmt1(tag codeStmt, out *ir.Nodes) ir.Node {
 		op := r.op()
 		lhs := r.expr()
 		pos := r.pos()
-		n := ir.NewAssignOpStmt(pos, op, lhs, ir.NewBasicLit(pos, one))
+		n := ir.NewAssignOpStmt(pos, op, lhs, ir.NewOne(pos, lhs.Type()))
 		n.IncDec = true
 		return n
 
@@ -2176,7 +2176,7 @@ func (r *reader) expr() (res ir.Node) {
 		pos := r.pos()
 		typ := r.typ()
 		val := FixValue(typ, r.Value())
-		return typed(typ, ir.NewBasicLit(pos, val))
+		return ir.NewBasicLit(pos, typ, val)
 
 	case exprNil:
 		pos := r.pos()
@@ -3152,7 +3152,7 @@ func (r *reader) exprs() []ir.Node {
 // uintptr-typed word from the dictionary parameter.
 func (r *reader) dictWord(pos src.XPos, idx int) ir.Node {
 	base.AssertfAt(r.dictParam != nil, pos, "expected dictParam in %v", r.curfn)
-	return typecheck.Expr(ir.NewIndexExpr(pos, r.dictParam, ir.NewBasicLit(pos, constant.MakeInt64(int64(idx)))))
+	return typecheck.Expr(ir.NewIndexExpr(pos, r.dictParam, ir.NewInt(pos, int64(idx))))
 }
 
 // rttiWord is like dictWord, but converts it to *byte (the type used
diff --git a/src/cmd/compile/internal/walk/switch.go b/src/cmd/compile/internal/walk/switch.go
index 67ccb2e5d1..2fc8aefe5f 100644
--- a/src/cmd/compile/internal/walk/switch.go
+++ b/src/cmd/compile/internal/walk/switch.go
@@ -233,7 +233,7 @@ func (s *exprSwitch) flush() {
 			s.done.Append(ir.NewBranchStmt(pos, ir.OGOTO, endLabel))
 
 			// Add length case to outer switch.
-			cas := ir.NewBasicLit(pos, constant.MakeInt64(runLen(run)))
+			cas := ir.NewInt(pos, runLen(run))
 			jmp := ir.NewBranchStmt(pos, ir.OGOTO, label)
 			outer.Add(pos, cas, nil, jmp)
 		}