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On Freitag 29 Mai 2009, Graham Murray wrote: |
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> Stroller <stroller@××××××××××××××××××.uk> writes: |
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> > But, surely "-march=" also instructs gcc to support the additional |
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> > instructions. Suggest you re-read Daniel's post that I was replying |
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> > to. |
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> > |
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> > What's the difference between supporting the "certain set of |
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> > instructions" with "-march=" and doing so with USEs? |
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> > |
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> > Or doesn't "-march=" support additional "certain sets of |
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> > instructions". What does it do, then? |
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> |
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> I am not sure, |
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> |
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> $ gcc -Q --help=target -march=core2 |
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> The following options are target specific: |
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> -m128bit-long-double [disabled] |
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> -m32 [enabled] |
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> -m3dnow [disabled] |
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> -m3dnowa [disabled] |
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> -m64 [disabled] |
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> -m80387 [enabled] |
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> -m96bit-long-double [enabled] |
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> -mabm [disabled] |
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> -maccumulate-outgoing-args [disabled] |
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> -maes [disabled] |
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> -malign-double [disabled] |
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> -malign-functions= |
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> -malign-jumps= |
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> -malign-loops= |
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> -malign-stringops [enabled] |
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> -march= core2 |
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> -masm= |
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> -mavx [disabled] |
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> -mbranch-cost= |
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> -mcld [disabled] |
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> -mcmodel= |
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> -mcx16 [disabled] |
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> -mfancy-math-387 [enabled] |
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> -mfma [disabled] |
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> -mforce-drap [disabled] |
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> -mfp-ret-in-387 [enabled] |
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> -mfpmath= |
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> -mfused-madd [enabled] |
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> -mglibc [enabled] |
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> -mhard-float [enabled] |
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> -mieee-fp [enabled] |
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> -mincoming-stack-boundary= |
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> -minline-all-stringops [disabled] |
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> -minline-stringops-dynamically [disabled] |
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> -mintel-syntax [disabled] |
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> -mlarge-data-threshold= |
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> -mmmx [disabled] |
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> -mms-bitfields [disabled] |
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> -mno-align-stringops [disabled] |
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> -mno-fancy-math-387 [disabled] |
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> -mno-fused-madd [disabled] |
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> -mno-push-args [disabled] |
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> -mno-red-zone [disabled] |
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> -mno-sse4 [enabled] |
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> -momit-leaf-frame-pointer [disabled] |
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> -mpc |
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> -mpclmul [disabled] |
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> -mpopcnt [disabled] |
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> -mpreferred-stack-boundary= |
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> -mpush-args [enabled] |
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> -mrecip [disabled] |
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> -mred-zone [enabled] |
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> -mregparm= |
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> -mrtd [disabled] |
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> -msahf [disabled] |
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> -msoft-float [disabled] |
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> -msse [disabled] |
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> -msse2 [disabled] |
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> -msse2avx [disabled] |
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> -msse3 [disabled] |
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> -msse4 [disabled] |
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> -msse4.1 [disabled] |
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> -msse4.2 [disabled] |
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> -msse4a [disabled] |
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> -msse5 [disabled] |
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> -msseregparm [disabled] |
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> -mssse3 [disabled] |
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> -mstack-arg-probe [disabled] |
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> -mstackrealign [enabled] |
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> -mstringop-strategy= |
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> -mtls-dialect= |
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> -mtls-direct-seg-refs [enabled] |
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> -mtune= |
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> -muclibc [disabled] |
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> -mveclibabi= |
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|
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get this: |
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dev.gentoo.org/~dirtyepic/bin/analyze-x86 |
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|
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and let it run, for example: |
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/analyze-x86 /bin/gzip |
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Checking vendor_id string... AuthenticAMD 64 |
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Disassembling /bin/gzip, please wait... |
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i486: 0 i586: 0 ppro: 36 mmx: 46 3dnow: 0 ext3dnow: 0 sse: |
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0 sse2: 4 sse3: 0 |
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/bin/gzip will run on AMD Athlon64 or higher processor. |
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|
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or this: |
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/analyze-x86 /bin/bash |
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Checking vendor_id string... AuthenticAMD 64 |
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Disassembling /bin/bash, please wait... |
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i486: 0 i586: 0 ppro: 369 mmx: 876 3dnow: 0 ext3dnow: 0 sse: |
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120 sse2: 0 sse3: 0 |
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/bin/bash will run on Pentium III (pentium3) or higher processor. |
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|
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and march=k8-sse3 -msse3 -O2 -pipe were my flags. Seems that a lot of stuff |
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got turned on ;) |
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|
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mplayer is even more 'interessting': |
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./analyze-x86 /usr/bin/mplayer |
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Checking vendor_id string... AuthenticAMD 64 |
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Disassembling /usr/bin/mplayer, please wait... |
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i486: 3948 i586: 14 ppro: 7573 mmx: 164986 3dnow: 5331 ext3dnow: 768 sse: |
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31407 sse2: 27712 sse3: 51 |
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|
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This binary was found to contain the cpuid instruction. |
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It may be able to conditionally execute instructions if |
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they are supported on the host (i586+). |
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|
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/usr/bin/mplayer will run on AMD Athlon64 w/ SSE3 or higher processor. |
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