src/cmd/compile/internal/gc: remove now unnecessary restriction on float exponent parsing
https://go-review.googlesource.com/#/c/13778/ fixed this issue in math/big.
Remove restriction in compiler.
Fixes #11326.
Change-Id: I1429d0dd0d79431706c65616413373fff58f081e
Reviewed-on: https://go-review.googlesource.com/14830
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/src/cmd/compile/internal/gc/mparith3.go b/src/cmd/compile/internal/gc/mparith3.go
index bf37f2d..f91a64b 100644
--- a/src/cmd/compile/internal/gc/mparith3.go
+++ b/src/cmd/compile/internal/gc/mparith3.go
@@ -9,7 +9,6 @@
"cmd/internal/obj"
"fmt"
"math"
- "strings"
)
/// implements float arihmetic
@@ -154,30 +153,6 @@
as = as[1:]
}
- // The spec requires accepting exponents that fit in int32.
- // Don't accept much more than that.
- // Count digits in exponent and stop early if there are too many.
- if i := strings.Index(as, "e"); i >= 0 {
- i++
- if i < len(as) && (as[i] == '-' || as[i] == '+') {
- i++
- }
- for i < len(as) && as[i] == '0' {
- i++
- }
- // TODO(rsc): This should be > 10, because we're supposed
- // to accept any signed 32-bit int as an exponent.
- // But that's not working terribly well, so we deviate from the
- // spec in order to make sure that what we accept works.
- // We can remove this restriction once those larger exponents work.
- // See golang.org/issue/11326 and test/fixedbugs/issue11326*.go.
- if len(as)-i > 8 {
- Yyerror("malformed constant: %s (exponent too large)", as)
- a.Val.SetUint64(0)
- return
- }
- }
-
f, ok := a.Val.SetString(as)
if !ok {
// At the moment we lose precise error cause;
diff --git a/test/fixedbugs/issue11326.go b/test/fixedbugs/issue11326.go
index fd1fab3..bb19796 100644
--- a/test/fixedbugs/issue11326.go
+++ b/test/fixedbugs/issue11326.go
@@ -4,25 +4,20 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
+// Tests for golang.org/issue/11326.
+
package main
-import "fmt"
-
func main() {
- var g = 1e81391777742999 // ERROR "exponent too large"
- // The next should only cause a problem when converted to float64
- // by the assignment, but instead the compiler rejects it outright,
- // rather than mishandle it. Specifically, when handled, 'var h' prints:
- // issue11326.go:N: constant 0.93342e+536870911 overflows float64
- // The rejection of 'var i' is just insurance. It seems to work correctly.
- // See golang.org/issue/11326.
- // var h = 1e2147483647 // should be "1.00000e+2147483647 overflows float64"
- var h = 1e2147483647 // ERROR "exponent too large"
- // var i = 1e214748364 // should be "1.00000e\+214748364 overflows float64"
- var i = 1e214748364 // ERROR "exponent too large"
- var j = 1e21474836 // ERROR "1.00000e\+21474836 overflows float64"
- var k = 1e2147483 // ERROR "1.00000e\+2147483 overflows float64"
- var l = 1e214748 // ERROR "1.00000e\+214748 overflows float64"
- var m = 1e21474 // ERROR "1.00000e\+21474 overflows float64"
- fmt.Println(g)
+ var _ = 1e2147483647 // ERROR "constant too large"
+ var _ = 1e646456993 // ERROR "constant too large"
+ var _ = 1e646456992 // ERROR "1.00000e\+646456992 overflows float64"
+ var _ = 1e64645699 // ERROR "1.00000e\+64645699 overflows float64"
+ var _ = 1e6464569 // ERROR "1.00000e\+6464569 overflows float64"
+ var _ = 1e646456 // ERROR "1.00000e\+646456 overflows float64"
+ var _ = 1e64645 // ERROR "1.00000e\+64645 overflows float64"
+ var _ = 1e6464 // ERROR "1.00000e\+6464 overflows float64"
+ var _ = 1e646 // ERROR "1.00000e\+646 overflows float64"
+ var _ = 1e309 // ERROR "1.00000e\+309 overflows float64"
+ var _ = 1e308
}
diff --git a/test/fixedbugs/issue11326b.go b/test/fixedbugs/issue11326b.go
index 00effbc..6a6ae2f 100644
--- a/test/fixedbugs/issue11326b.go
+++ b/test/fixedbugs/issue11326b.go
@@ -6,36 +6,36 @@
package main
+// Tests for golang.org/issue/11326.
+
func main() {
- /* TODO(rsc): Should work but does not. See golang.org/issue/11326.
{
- const n = 1e2147483647
- const d = 1e2147483646
+ const n = 1e646456992
+ const d = 1e646456991
x := n / d
if x != 10.0 {
println("incorrect value:", x)
}
}
{
- const n = 1e214748364
- const d = 1e214748363
- x := n / d
- if x != 10.0 {
- println("incorrect value:", x)
- }
- }
- */
- {
- const n = 1e21474836
- const d = 1e21474835
+ const n = 1e64645699
+ const d = 1e64645698
x := n / d
if x != 10.0 {
println("incorrect value:", x)
}
}
{
- const n = 1e2147483
- const d = 1e2147482
+ const n = 1e6464569
+ const d = 1e6464568
+ x := n / d
+ if x != 10.0 {
+ println("incorrect value:", x)
+ }
+ }
+ {
+ const n = 1e646456
+ const d = 1e646455
x := n / d
if x != 10.0 {
println("incorrect value:", x)
