From cfc002f30b7028be0edba24d5d084b62066fbf9b Mon Sep 17 00:00:00 2001
From: Richard Musiol <mail@richard-musiol.de>
Date: Wed, 13 Nov 2013 15:16:19 -0800
Subject: [PATCH] go.tools/go/types: Do not throw error on division of float
 variables by zero.

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/26040043
---
 go/types/expr.go            | 2 +-
 go/types/testdata/stmt0.src | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/go/types/expr.go b/go/types/expr.go
index 0702d360..4a789024 100644
--- a/go/types/expr.go
+++ b/go/types/expr.go
@@ -762,7 +762,7 @@ func (check *checker) binary(x *operand, lhs, rhs ast.Expr, op token.Token) {
 		return
 	}
 
-	if (op == token.QUO || op == token.REM) && y.mode == constant && exact.Sign(y.val) == 0 {
+	if (op == token.QUO || op == token.REM) && (x.mode == constant || !isFloat(x.typ)) && y.mode == constant && exact.Sign(y.val) == 0 {
 		check.invalidOp(y.pos(), "division by zero")
 		x.mode = invalid
 		return
diff --git a/go/types/testdata/stmt0.src b/go/types/testdata/stmt0.src
index f7be5d90..167c9ce6 100644
--- a/go/types/testdata/stmt0.src
+++ b/go/types/testdata/stmt0.src
@@ -52,6 +52,8 @@ func assignments1() {
 	i += "foo" /* ERROR "cannot convert.*int" */
 
 	f -= 1
+	f /= 0
+	f = float32(1.0)/0
 	f -= "foo" /* ERROR "cannot convert.*float64" */
 
 	c *= 1