http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53113
--- Comment #15 from David Kredba <nheghathivhistha at gmail dot com> ---
For me it looks like that GCC build process is taking from some internal
definition that AVX should be present on Core2 and enables it for libitm. Patch
attached in this bug report works for gcc-4.9-20131222 fine too.
"Known to fail" can contain 4.8.2 (and 4.9.0 branch too if possible).
Gcc knows that there is no AVX, both for 4.8.2 and 4.9.0 snapshot but both
versions enable AVX for libitim for me:
4.9.0:
gcc -march=native -Q --help=targetThe following options are target specific:
-m128bit-long-double [disabled]
-m32 [disabled]
-m3dnow [disabled]
-m3dnowa [disabled]
-m64 [enabled]
-m80387 [enabled]
-m8bit-idiv [disabled]
-m96bit-long-double [enabled]
-mabi= sysv
-mabm [disabled]
-maccumulate-outgoing-args [disabled]
-maddress-mode= short
-madx [disabled]
-maes [disabled]
-malign-double [disabled]
-malign-functions= 0
-malign-jumps= 0
-malign-loops= 0
-malign-stringops [enabled]
-mandroid [disabled]
-march= core2
-masm= att
-mavx [disabled]
-mavx2 [disabled]
-mavx256-split-unaligned-load [disabled]
-mavx256-split-unaligned-store [disabled]
-mavx512cd [disabled]
-mavx512er [disabled]
-mavx512f [disabled]
-mavx512pf [disabled]
-mbionic [disabled]
-mbmi [disabled]
-mbmi2 [disabled]
-mbranch-cost= 0
-mcld [disabled]
-mcmodel= 32
-mcpu=
-mcrc32 [disabled]
-mcx16 [enabled]
-mdispatch-scheduler [disabled]
-mdump-tune-features [disabled]
-mf16c [disabled]
-mfancy-math-387 [enabled]
-mfentry [enabled]
-mfma [disabled]
-mfma4 [disabled]
-mforce-drap [disabled]
-mfp-ret-in-387 [enabled]
-mfpmath= 387
-mfsgsbase [disabled]
-mfused-madd
-mfxsr [enabled]
-mglibc [enabled]
-mhard-float [enabled]
-mhle [disabled]
-mieee-fp [enabled]
-mincoming-stack-boundary= 0
-minline-all-stringops [disabled]
-minline-stringops-dynamically [disabled]
-mintel-syntax
-mlarge-data-threshold= 0x10000
-mlong-double-64 [disabled]
-mlong-double-80 [enabled]
-mlwp [disabled]
-mlzcnt [disabled]
-mmemcpy-strategy=
-mmemset-strategy=
-mmmx [enabled]
-mmovbe [disabled]
-mms-bitfields [disabled]
-mno-align-stringops [disabled]
-mno-default [disabled]
-mno-fancy-math-387 [disabled]
-mno-push-args [disabled]
-mno-red-zone [disabled]
-mno-sse4 [disabled]
-momit-leaf-frame-pointer [disabled]
-mpc32 [disabled]
-mpc64 [disabled]
-mpc80 [disabled]
-mpclmul [disabled]
-mpopcnt [disabled]
-mprefer-avx128 [disabled]
-mpreferred-stack-boundary= 0
-mprfchw [disabled]
-mpush-args [enabled]
-mrdrnd [disabled]
-mrdseed [disabled]
-mrecip [disabled]
-mrecip=
-mred-zone [enabled]
-mregparm= 0
-mrtd [disabled]
-mrtm [disabled]
-msahf [enabled]
-msoft-float [disabled]
-msse [enabled]
-msse2 [enabled]
-msse2avx [disabled]
-msse3 [enabled]
-msse4 [disabled]
-msse4.1 [enabled]
-msse4.2 [disabled]
-msse4a [disabled]
-msse5
-msseregparm [disabled]
-mssse3 [enabled]
-mstack-arg-probe [disabled]
-mstack-protector-guard= tls
-mstackrealign [enabled]
-mstringop-strategy= [default]
-mtbm [disabled]
-mtls-dialect= gnu
-mtls-direct-seg-refs [enabled]
-mtune-ctrl=
-mtune= core2
-muclibc [disabled]
-mveclibabi= [default]
-mvect8-ret-in-mem [disabled]
-mvzeroupper [disabled]
-mx32 [disabled]
-mxop [disabled]
-mxsave [disabled]
-mxsaveopt [disabled]
Known assembler dialects (for use with the -masm-dialect= option):
att intel
Known ABIs (for use with the -mabi= option):
ms sysv
Known code models (for use with the -mcmodel= option):
32 kernel large medium small
Valid arguments to -mfpmath=:
387 387+sse 387,sse both sse sse+387 sse,387
Known vectorization library ABIs (for use with the -mveclibabi= option):
acml svml
Known address mode (for use with the -maddress-mode= option):
long short
Known stack protector guard (for use with the -mstack-protector-guard=
option):
global tls
Valid arguments to -mstringop-strategy=:
byte_loop libcall loop rep_4byte rep_8byte rep_byte unrolled_loop
vector_loop
Known TLS dialects (for use with the -mtls-dialect= option):
gnu gnu2
4.8.2:
/usr/x86_64-pc-linux-gnu/gcc-bin/4.8.2/gcc -march=native -Q --help=target
The following options are target specific:
-m128bit-long-double [disabled]
-m32 [disabled]
-m3dnow [disabled]
-m3dnowa [disabled]
-m64 [enabled]
-m80387 [enabled]
-m8bit-idiv [disabled]
-m96bit-long-double [enabled]
-mabi= sysv
-mabm [disabled]
-maccumulate-outgoing-args [disabled]
-maddress-mode= short
-madx [disabled]
-maes [disabled]
-malign-double [disabled]
-malign-functions= 0
-malign-jumps= 0
-malign-loops= 0
-malign-stringops [enabled]
-mandroid [disabled]
-march= core2
-masm= att
-mavx [disabled]
-mavx2 [disabled]
-mavx256-split-unaligned-load [disabled]
-mavx256-split-unaligned-store [disabled]
-mbionic [disabled]
-mbmi [disabled]
-mbmi2 [disabled]
-mbranch-cost= 0
-mcld [disabled]
-mcmodel= 32
-mcpu=
-mcrc32 [disabled]
-mcx16 [enabled]
-mdispatch-scheduler [disabled]
-mf16c [disabled]
-mfancy-math-387 [enabled]
-mfentry [enabled]
-mfma [disabled]
-mfma4 [disabled]
-mforce-drap [disabled]
-mfp-ret-in-387 [enabled]
-mfpmath= 387
-mfsgsbase [disabled]
-mfused-madd
-mfxsr [enabled]
-mglibc [enabled]
-mhard-float [enabled]
-mhle [disabled]
-mieee-fp [enabled]
-mincoming-stack-boundary= 0
-minline-all-stringops [disabled]
-minline-stringops-dynamically [disabled]
-mintel-syntax
-mlarge-data-threshold= 0x10000
-mlong-double-64 [disabled]
-mlong-double-80 [enabled]
-mlwp [disabled]
-mlzcnt [disabled]
-mmmx [disabled]
-mmovbe [disabled]
-mms-bitfields [disabled]
-mno-align-stringops [disabled]
-mno-fancy-math-387 [disabled]
-mno-push-args [disabled]
-mno-red-zone [disabled]
-mno-sse4 [disabled]
-momit-leaf-frame-pointer [disabled]
-mpc32 [disabled]
-mpc64 [disabled]
-mpc80 [disabled]
-mpclmul [disabled]
-mpopcnt [disabled]
-mprefer-avx128 [disabled]
-mpreferred-stack-boundary= 0
-mprfchw [disabled]
-mpush-args [enabled]
-mrdrnd [disabled]
-mrdseed [disabled]
-mrecip [disabled]
-mrecip=
-mred-zone [enabled]
-mregparm= 0
-mrtd [disabled]
-mrtm [disabled]
-msahf [enabled]
-msoft-float [disabled]
-msse [enabled]
-msse2 [enabled]
-msse2avx [disabled]
-msse3 [enabled]
-msse4 [disabled]
-msse4.1 [enabled]
-msse4.2 [disabled]
-msse4a [disabled]
-msse5
-msseregparm [disabled]
-mssse3 [enabled]
-mstack-arg-probe [disabled]
-mstackrealign [enabled]
-mstringop-strategy= [default]
-mtbm [disabled]
-mtls-dialect= gnu
-mtls-direct-seg-refs [enabled]
-mtune= core2
-muclibc [disabled]
-mveclibabi= [default]
-mvect8-ret-in-mem [disabled]
-mvzeroupper [disabled]
-mx32 [disabled]
-mxop [disabled]
-mxsave [disabled]
-mxsaveopt [disabled]
Known assembler dialects (for use with the -masm-dialect= option):
att intel
Known ABIs (for use with the -mabi= option):
ms sysv
Known code models (for use with the -mcmodel= option):
32 kernel large medium small
Valid arguments to -mfpmath=:
387 387+sse 387,sse both sse sse+387 sse,387
Known vectorization library ABIs (for use with the -mveclibabi= option):
acml svml
Known address mode (for use with the -maddress-mode= option):
long short
Valid arguments to -mstringop-strategy=:
byte_loop libcall loop rep_4byte rep_8byte rep_byte unrolled_loop
Known TLS dialects (for use with the -mtls-dialect= option):
gnu gnu2
