Stroller <strol...@stellar.eclipse.co.uk> writes: > But, surely "-march=" also instructs gcc to support the additional > instructions. Suggest you re-read Daniel's post that I was replying > to. > > What's the difference between supporting the "certain set of > instructions" with "-march=" and doing so with USEs? > > Or doesn't "-march=" support additional "certain sets of > instructions". What does it do, then?
I am not sure, $ gcc -Q --help=target -march=core2 The following options are target specific: -m128bit-long-double [disabled] -m32 [enabled] -m3dnow [disabled] -m3dnowa [disabled] -m64 [disabled] -m80387 [enabled] -m96bit-long-double [enabled] -mabm [disabled] -maccumulate-outgoing-args [disabled] -maes [disabled] -malign-double [disabled] -malign-functions= -malign-jumps= -malign-loops= -malign-stringops [enabled] -march= core2 -masm= -mavx [disabled] -mbranch-cost= -mcld [disabled] -mcmodel= -mcx16 [disabled] -mfancy-math-387 [enabled] -mfma [disabled] -mforce-drap [disabled] -mfp-ret-in-387 [enabled] -mfpmath= -mfused-madd [enabled] -mglibc [enabled] -mhard-float [enabled] -mieee-fp [enabled] -mincoming-stack-boundary= -minline-all-stringops [disabled] -minline-stringops-dynamically [disabled] -mintel-syntax [disabled] -mlarge-data-threshold= -mmmx [disabled] -mms-bitfields [disabled] -mno-align-stringops [disabled] -mno-fancy-math-387 [disabled] -mno-fused-madd [disabled] -mno-push-args [disabled] -mno-red-zone [disabled] -mno-sse4 [enabled] -momit-leaf-frame-pointer [disabled] -mpc -mpclmul [disabled] -mpopcnt [disabled] -mpreferred-stack-boundary= -mpush-args [enabled] -mrecip [disabled] -mred-zone [enabled] -mregparm= -mrtd [disabled] -msahf [disabled] -msoft-float [disabled] -msse [disabled] -msse2 [disabled] -msse2avx [disabled] -msse3 [disabled] -msse4 [disabled] -msse4.1 [disabled] -msse4.2 [disabled] -msse4a [disabled] -msse5 [disabled] -msseregparm [disabled] -mssse3 [disabled] -mstack-arg-probe [disabled] -mstackrealign [enabled] -mstringop-strategy= -mtls-dialect= -mtls-direct-seg-refs [enabled] -mtune= -muclibc [disabled] -mveclibabi=
