On Thu, Apr 25, 2013 at 03:44:08PM +0200, Richard Biener wrote:
> On Thu, Apr 25, 2013 at 3:23 PM, Marek Polacek <pola...@redhat.com> wrote:
> > This is an attempt to fix PR57066, where when folding logb call,
> > we returned -Inf for logb(-Inf), which is not correct.
> >
> > I had to adjust one testcase, because it checked for a wrong value.
> >
> > What I don't know yet is what we should return for -Nan, it should be
> > in C9X standard, but I don't have it by hand.
> >
> > Does this look sane? So far regtested/bootstrapped on x86_64-linux.
> >
> > 2013-04-25 Marek Polacek <pola...@redhat.com>
> >
> > * builtins.c (fold_builtin_logb): Return +Inf for -Inf.
> >
> > * gcc.dg/torture/builtin-logb-1.c: Adjust testcase.
> >
> > --- gcc/builtins.c.mp 2013-04-25 12:52:37.463451032 +0200
> > +++ gcc/builtins.c 2013-04-25 14:26:33.963099851 +0200
> > @@ -9698,7 +9698,12 @@ fold_builtin_logb (location_t loc, tree
> > case rvc_inf:
> > /* If arg is Inf or NaN and we're logb, return it. */
> > if (TREE_CODE (rettype) == REAL_TYPE)
> > - return fold_convert_loc (loc, rettype, arg);
> > + {
> > + /* For logb(-Inf) we have to return +Inf. */
> > + if (value->cl == rvc_inf && !tree_expr_nonnegative_p (arg))
> > + real_inf (TREE_REAL_CST_PTR (arg));
>
> Please don't modify arg in-place but simply use
>
> REAL_VALUE_TYPE tem;
> real_inf (&tem);
> return build_real (rettype, tem);
>
Okay, patch updated. Ok now (which branches, all active?)?
Regtested/bootstrapped again on x86_64-linux.
2013-04-25 Marek Polacek <pola...@redhat.com>
* builtins.c (fold_builtin_logb): Return +Inf for -Inf.
* gcc.dg/torture/builtin-logb-1.c: Adjust testcase.
--- gcc/builtins.c.mp 2013-04-25 12:52:37.463451032 +0200
+++ gcc/builtins.c 2013-04-25 16:29:59.054615841 +0200
@@ -9698,7 +9698,16 @@ fold_builtin_logb (location_t loc, tree
case rvc_inf:
/* If arg is Inf or NaN and we're logb, return it. */
if (TREE_CODE (rettype) == REAL_TYPE)
- return fold_convert_loc (loc, rettype, arg);
+ {
+ /* For logb(-Inf) we have to return +Inf. */
+ if (value->cl == rvc_inf && !tree_expr_nonnegative_p (arg))
+ {
+ REAL_VALUE_TYPE tem;
+ real_inf (&tem);
+ return build_real (rettype, tem);
+ }
+ return fold_convert_loc (loc, rettype, arg);
+ }
/* Fall through... */
case rvc_zero:
/* Zero may set errno and/or raise an exception for logb, also
--- gcc/testsuite/gcc.dg/torture/builtin-logb-1.c.mp 2013-04-25
13:23:18.408224450 +0200
+++ gcc/testsuite/gcc.dg/torture/builtin-logb-1.c 2013-04-25
16:29:19.842490916 +0200
@@ -48,19 +48,19 @@ extern void link_error(int);
/* Test if FUNCRES(FUNC(NEG FUNCARG(ARGARG))) is false. Check the
sign as well. */
#ifndef __SPU__
-#define TESTIT3(FUNC,NEG,FUNCARG,ARGARG,FUNCRES) do { \
+#define TESTIT3(FUNC,NEG,FUNCARG,ARGARG,FUNCRES,NEG2) do { \
if (!__builtin_##FUNCRES##f(__builtin_##FUNC(NEG
__builtin_##FUNCARG##f(ARGARG))) \
- || CKSGN_F(__builtin_##FUNC##f(NEG __builtin_##FUNCARG##f(ARGARG)), NEG
__builtin_##FUNCARG##f(ARGARG))) \
+ || CKSGN_F(__builtin_##FUNC##f(NEG __builtin_##FUNCARG##f(ARGARG)), NEG2
__builtin_##FUNCARG##f(ARGARG))) \
link_error(__LINE__); \
if (!__builtin_##FUNCRES(__builtin_##FUNC(NEG __builtin_##FUNCARG(ARGARG))) \
- || CKSGN(__builtin_##FUNC(NEG __builtin_##FUNCARG(ARGARG)), NEG
__builtin_##FUNCARG(ARGARG))) \
+ || CKSGN(__builtin_##FUNC(NEG __builtin_##FUNCARG(ARGARG)), NEG2
__builtin_##FUNCARG(ARGARG))) \
link_error(__LINE__); \
if (!__builtin_##FUNCRES##l(__builtin_##FUNC##l(NEG
__builtin_##FUNCARG##l(ARGARG))) \
- || CKSGN_L(__builtin_##FUNC##l(NEG __builtin_##FUNCARG##l(ARGARG)), NEG
__builtin_##FUNCARG##l(ARGARG))) \
+ || CKSGN_L(__builtin_##FUNC##l(NEG __builtin_##FUNCARG##l(ARGARG)), NEG2
__builtin_##FUNCARG##l(ARGARG))) \
link_error(__LINE__); \
} while (0)
#else
-#define TESTIT3(FUNC,NEG,FUNCARG,ARGARG,FUNCRES) do { \
+#define TESTIT3(FUNC,NEG,FUNCARG,ARGARG,FUNCRES,NEG2) do { \
/* SPU single-precision floating point format does not support Inf or Nan.
*/ \
if (!__builtin_##FUNCRES(__builtin_##FUNC(NEG __builtin_##FUNCARG(ARGARG))) \
|| CKSGN(__builtin_##FUNC(NEG __builtin_##FUNCARG(ARGARG)), NEG
__builtin_##FUNCARG(ARGARG))) \
@@ -173,15 +173,15 @@ foo(void)
/* Test for f(+-Inf) -> +-Inf and f(+-NaN) -> +-NaN, regardless of
the radix. */
- TESTIT3 (logb, ,inf, , isinf);
- TESTIT3 (logb, - ,inf, , isinf);
- TESTIT3 (logb, ,nan, "", isnan);
- TESTIT3 (logb, - ,nan, "", isnan);
-
- TESTIT3 (significand, ,inf, , isinf);
- TESTIT3 (significand, - ,inf, , isinf);
- TESTIT3 (significand, ,nan, "", isnan);
- TESTIT3 (significand, - ,nan, "", isnan);
+ TESTIT3 (logb, ,inf, , isinf, );
+ TESTIT3 (logb, - ,inf, , isinf, );
+ TESTIT3 (logb, ,nan, "", isnan, );
+ TESTIT3 (logb, - ,nan, "", isnan, -);
+
+ TESTIT3 (significand, ,inf, , isinf, );
+ TESTIT3 (significand, - ,inf, , isinf, -);
+ TESTIT3 (significand, ,nan, "", isnan, );
+ TESTIT3 (significand, - ,nan, "", isnan, -);
}
int main()
Marek
