https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123015
Bug ID: 123015
Summary: __builtin_isnan() should not trigger exception on
sNaNs with -fsignaling-nans
Product: gcc
Version: 15.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: tkisuki at tachyum dot com
Target Milestone: ---
#include <math.h>
int f(float a)
{
return __builtin_isnan(a);
}
int f2(float a)
{
return isnan(a);
}
compiling the above code with gcc -S -O, front end generates:
;; Function f (null)
;; enabled by -tree-original
{
return a unord a;
}
;; Function f2 (null)
;; enabled by -tree-original
{
return a unord a;
}
and compiling with gcc -S -O -fsignaling-nans, front end generates;
;; Function f (null)
;; enabled by -tree-original
{
return a unord a;
}
;; Function f2 (null)
;; enabled by -tree-original
{
return __isnanf (a);
}
With -fsignaling-nans, isnan() is now a call, but __builtin_isnan() is
still "a unord a" and __builtin_isnan() will still trigger an exception on
sNaNs.
