This function:
#define PMD_MASK (~((1UL << 23) - 1))
void clear_pmd_range(unsigned long start, unsigned long end)
{
if (!(start & ~PMD_MASK) && !(end & ~PMD_MASK))
f();
}
should be optimized to generate the same code as this function:
void clear_pmd_range2(unsigned long start, unsigned long end)
{
if (!((start | end) & ~PMD_MASK))
f();
}
that is, use only one conditional branch (see also
http://linux.bkbits.net:8080/linux-2.5/[EMAIL PROTECTED]|[EMAIL PROTECTED]).
--
Summary: Unnecessary jump from &&
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P2
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: falk at debian dot org
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20192
