https://bugs.llvm.org/show_bug.cgi?id=46432
Bug ID: 46432
Summary: Failure to optimize double overflow comparison to
__builtin_add_overflow
Product: libraries
Version: trunk
Hardware: PC
OS: Linux
Status: NEW
Severity: enhancement
Priority: P
Component: Scalar Optimizations
Assignee: unassignedb...@nondot.org
Reporter: gabrav...@gmail.com
CC: llvm-bugs@lists.llvm.org
unsigned foo(unsigned a, unsigned b)
{
unsigned sum = a + b;
if (sum < a)
abort();
if (sum < b)
abort();
return sum;
}
This can be optimized to remove one of the two checks, or to this :
unsigned foo(unsigned a, unsigned b)
{
unsigned sum;
if (__builtin_add_overflow(a, b, &sum))
abort();
else
return sum;
}
This transformation is done by GCC, but not by LLVM.
--
You are receiving this mail because:
You are on the CC list for the bug._______________________________________________
llvm-bugs mailing list
llvm-bugs@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
