gc: fix up floating point NaN comparisons

Fixes issue 167.

R=ken2
http://codereview.appspot.com/155062

2 files changed, 92 insertions, 4 deletions

diff --git a/test/float_lit.go b/test/float_lit.go
index a78a6e924..be4460e43 100644
--- a/test/float_lit.go
+++ b/test/float_lit.go
@@ -20,8 +20,8 @@ close(da float64, ia, ib int64, pow int) bool
 	db := float64(ia) / float64(ib);
 	db *= pow10(pow);
 
-	if da == 0 {
-		if db == 0 {
+	if da == 0 || db == 0 {
+		if da == 0 && db == 0 {
 			return true;
 		}
 		return false;
@@ -59,8 +59,8 @@ main()
 	if !close(-210e3, -210, 1, 3) { print("-210e3 is ", -210e3, "\n"); }
 
 	if !close(0E-1, 0, 1, 0) { print("0E-1 is ", 0E-1, "\n"); }
-	if !close(+0e23, 0, 1, 23) { print("+0e23 is ", +0e23, "\n"); }
-	if !close(-0e345, 0, 1, 345) { print("-0e345 is ", -0e345, "\n"); }
+	if !close(+0e23, 0, 1, 1) { print("+0e23 is ", +0e23, "\n"); }
+	if !close(-0e345, 0, 1, 1) { print("-0e345 is ", -0e345, "\n"); }
 
 	if !close(0E1, 0, 1, 1) { print("0E1 is ", 0E1, "\n"); }
 	if !close(+10e23, 10, 1, 23) { print("+10e23 is ", +10e23, "\n"); }
diff --git a/test/floatcmp.go b/test/floatcmp.go
new file mode 100644
index 000000000..26fc6ad14
--- /dev/null
+++ b/test/floatcmp.go
@@ -0,0 +1,88 @@
+// $G $F.go && $L $F.$A && ./$A.out
+
+// Copyright 2009 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 main
+
+import "math"
+
+type floatTest struct {
+	name string;
+	expr bool;
+	want bool;
+}
+
+var nan float64 = math.NaN();
+var f float64 = 1;
+
+var tests = []floatTest{
+	floatTest{"nan == nan", nan == nan, false},
+	floatTest{"nan != nan", nan != nan, true},
+	floatTest{"nan < nan", nan < nan, false},
+	floatTest{"nan > nan", nan > nan, false},
+	floatTest{"nan <= nan", nan <= nan, false},
+	floatTest{"nan >= nan", nan >= nan, false},
+	floatTest{"f == nan", f == nan, false},
+	floatTest{"f != nan", f != nan, true},
+	floatTest{"f < nan", f < nan, false},
+	floatTest{"f > nan", f > nan, false},
+	floatTest{"f <= nan", f <= nan, false},
+	floatTest{"f >= nan", f >= nan, false},
+	floatTest{"nan == f", nan == f, false},
+	floatTest{"nan != f", nan != f, true},
+	floatTest{"nan < f", nan < f, false},
+	floatTest{"nan > f", nan > f, false},
+	floatTest{"nan <= f", nan <= f, false},
+	floatTest{"nan >= f", nan >= f, false},
+	floatTest{"!(nan == nan)", !(nan == nan), true},
+	floatTest{"!(nan != nan)", !(nan != nan), false},
+	floatTest{"!(nan < nan)", !(nan < nan), true},
+	floatTest{"!(nan > nan)", !(nan > nan), true},
+	floatTest{"!(nan <= nan)", !(nan <= nan), true},
+	floatTest{"!(nan >= nan)", !(nan >= nan), true},
+	floatTest{"!(f == nan)", !(f == nan), true},
+	floatTest{"!(f != nan)", !(f != nan), false},
+	floatTest{"!(f < nan)", !(f < nan), true},
+	floatTest{"!(f > nan)", !(f > nan), true},
+	floatTest{"!(f <= nan)", !(f <= nan), true},
+	floatTest{"!(f >= nan)", !(f >= nan), true},
+	floatTest{"!(nan == f)", !(nan == f), true},
+	floatTest{"!(nan != f)", !(nan != f), false},
+	floatTest{"!(nan < f)", !(nan < f), true},
+	floatTest{"!(nan > f)", !(nan > f), true},
+	floatTest{"!(nan <= f)", !(nan <= f), true},
+	floatTest{"!(nan >= f)", !(nan >= f), true},
+	floatTest{"!!(nan == nan)", !!(nan == nan), false},
+	floatTest{"!!(nan != nan)", !!(nan != nan), true},
+	floatTest{"!!(nan < nan)", !!(nan < nan), false},
+	floatTest{"!!(nan > nan)", !!(nan > nan), false},
+	floatTest{"!!(nan <= nan)", !!(nan <= nan), false},
+	floatTest{"!!(nan >= nan)", !!(nan >= nan), false},
+	floatTest{"!!(f == nan)", !!(f == nan), false},
+	floatTest{"!!(f != nan)", !!(f != nan), true},
+	floatTest{"!!(f < nan)", !!(f < nan), false},
+	floatTest{"!!(f > nan)", !!(f > nan), false},
+	floatTest{"!!(f <= nan)", !!(f <= nan), false},
+	floatTest{"!!(f >= nan)", !!(f >= nan), false},
+	floatTest{"!!(nan == f)", !!(nan == f), false},
+	floatTest{"!!(nan != f)", !!(nan != f), true},
+	floatTest{"!!(nan < f)", !!(nan < f), false},
+	floatTest{"!!(nan > f)", !!(nan > f), false},
+	floatTest{"!!(nan <= f)", !!(nan <= f), false},
+	floatTest{"!!(nan >= f)", !!(nan >= f), false},
+}
+
+func main() {
+	bad := false;
+	for _, t := range tests {
+		if t.expr != t.want {
+			if !bad {
+				bad = true;
+				println("BUG: floatcmp");
+			}
+			println(t.name, "=", t.expr, "want", t.want);
+		}
+	}
+}