This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug c/49128] New: gcc -mtune=native generates unsoported instructions
- From: "nathanael.schaeffer+ml at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Mon, 23 May 2011 16:45:34 +0000
- Subject: [Bug c/49128] New: gcc -mtune=native generates unsoported instructions
- Auto-submitted: auto-generated
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49128
Summary: gcc -mtune=native generates unsoported instructions
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Severity: critical
Priority: P3
Component: c
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: nathanael.schaeffer+ml@gmail.com
With gcc (GCC) 4.6.0 20110513 (prerelease)
I compile on my laptop :
----
Intel(R) Pentium(R) CPU U5400 @ 1.20GHz
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm
pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl
xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl e
st tm2 ssse3 cx16 xtpr pdcm popcnt lahf_lm arat dts
----
then "gcc -mtune=native" generates unsuported instructions like PINSRD (which
is part of SSE4.1 according to wikipedia, not supported by this CPU)
I guess -mtune=native uncorrectly detects this CPU in version 4.6.0
Version 4.5.x did work correctly.
WORKAROUND: use -mtune=core2