This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug tree-optimization/54295] New: [4.7 regression] Widening multiply-accumulate operation uses wrong value extension
- From: "rearnsha at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Fri, 17 Aug 2012 12:46:40 +0000
- Subject: [Bug tree-optimization/54295] New: [4.7 regression] Widening multiply-accumulate operation uses wrong value extension
- Auto-submitted: auto-generated
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54295
Bug #: 54295
Summary: [4.7 regression] Widening multiply-accumulate
operation uses wrong value extension
Classification: Unclassified
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: rearnsha@gcc.gnu.org
Target: arm aarch64
A widening multiply-accumulate operation can generate an incorrect result if
there are casts in expression.
Compile the attached test-case on ARM at -O2, the result is:
$./a.out
<aborted>
Correct result, as seen at -O1 is
$./a.out
$