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[Bug rtl-optimization/31799] New: Failed to optimize out test instruction
- From: "hjl at lucon dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 3 May 2007 14:21:45 -0000
- Subject: [Bug rtl-optimization/31799] New: Failed to optimize out test instruction
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
For
void
foo (int x, int *y, int *z)
{
*z = ++x;
if (x != 0)
*y = 1;
}
gcc 4.3 generates
foo:
.LFB2:
addl $1, %edi
testl %edi, %edi
movl %edi, (%rdx)
je .L3
movl $1, (%rsi)
.L3:
rep ; ret
But "testl %edi, %edi" isn't needed since "addl $1, %edi" sets proper
FLAGS_REG.
--
Summary: Failed to optimize out test instruction
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: hjl at lucon dot org
GCC target triplet: x86_64-unknown-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31799