In the following example the typecast (sign extension) from int
(32bit) to long (64bit) is missing. Before the compare the signed i1
is < 0 and unsigned u2 is > 0 and this should be kept when casting to
64bit long. Same issue for long long (also 64bit).
So we get correct ov=1 with gcc version <= 4.2, but wrong ov=0 with
gcc version >= 4.3.
This issue occurs with and without optimization.
gcc version: gcc-4_3_branch and trunk svn revision 133752
(gcc-4_2 and below runs fine)
int main()
{
int ov;
unsigned u2;
int i1;
i1 = 0;
u2 = (unsigned)2147483647 + 1 ;
(i1) += (u2);
if ( (long)(i1)<(long)(u2) ) ov = 1; else ov = 0;
return !ov;
}
--
Summary: typecast (sign extension) missing
Product: gcc
Version: 4.3.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: holger dot hopp at sap dot com
GCC build triplet: x86_64-unknown-linux-gnu
GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35900
