Follow up to PR 37635.
>From trans-intrinsic.c:
/* LEADZ (i) = (i == 0) ? BIT_SIZE (i)
: __builtin_clz(i) - (BIT_SIZE('int') - BIT_SIZE(i))
The conditional expression is necessary because the result of LEADZ(0)
is defined, but the result of __builtin_clz(0) is undefined for most
targets.
[...]
/* ??? For some combinations of targets and integer kinds, the condition
can be avoided if CLZ_DEFINED_VALUE_AT_ZERO is used. Later. */
--
Summary: Optimize LEADZ/TRAILZ for zero arguments
Product: gcc
Version: 4.4.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: fortran
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: burnus at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37780
