[Bug target/100347] [11/12 Regression] GCC 11 does not recognize skylake; translates "march=native" to "x86_64"

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100347

--- Comment #10 from Iain Sandoe <iains at gcc dot gnu.org> ---

build of 11.1 on macOS11 with no patches and default options

$ ./gcc/xgcc -Bgcc /source/test/general/empty-main.c -S -fverbose-asm 
 head -5 empty-main.s 
# GNU C17 (GCC) version 11.1.0 (x86_64-apple-darwin20)
#       compiled by GNU C version 11.1.0, GMP version 6.2.1, MPFR version
4.1.0, MPC version 1.2.1, isl version isl-0.23-GMP

# GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
# options passed: -fPIC -mmacosx-version-min=11.2.0 -mtune=core2



$ ./gcc/xgcc -Bgcc /source/test/general/empty-main.c -S -fverbose-asm
-march=native

 head -5 empty-main.s 
# GNU C17 (GCC) version 11.1.0 (x86_64-apple-darwin20)
#       compiled by GNU C version 11.1.0, GMP version 6.2.1, MPFR version
4.1.0, MPC version 1.2.1, isl version isl-0.23-GMP

# GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
# options passed: -march=skylake -mmmx -mpopcnt -msse -msse2 -msse3 -mssse3
-msse4.1 -msse4.2 -mavx -mavx2 -mno-sse4a -mno-fma4 -mno-xop -mfma -mno-avx512f
-mbmi -mbmi2 -maes -mpclmul -mno-avx512vl -mno-avx512bw -mno-avx512dq
-mno-avx512cd -mno-avx512er -mno-avx512pf -mno-avx512vbmi -mno-avx512ifma
-mno-avx5124vnniw -mno-avx5124fmaps -mno-avx512vpopcntdq -mno-avx512vbmi2
-mno-gfni -mno-vpclmulqdq -mno-avx512vnni -mno-avx512bitalg -mno-avx512bf16
-mno-avx512vp2intersect -mno-3dnow -madx -mabm -mno-cldemote -mclflushopt
-mno-clwb -mno-clzero -mcx16 -mno-enqcmd -mf16c -mfsgsbase -mfxsr -mhle -msahf
-mno-lwp -mlzcnt -mmovbe -mno-movdir64b -mno-movdiri -mno-mwaitx -mno-pconfig
-mno-pku -mno-prefetchwt1 -mprfchw -mno-ptwrite -mno-rdpid -mrdrnd -mrdseed
-mrtm -mno-serialize -msgx -mno-sha -mno-shstk -mno-tbm -mno-tsxldtrk -mno-vaes
-mno-waitpkg -mno-wbnoinvd -mxsave -mxsavec -mxsaveopt -mxsaves -mno-amx-tile
-mno-amx-int8 -mno-amx-bf16 -mno-uintr -mno-hreset -mno-kl -mno-widekl
-mno-avxvnni --param=l1-cache-size=32 --param=l1-cache-line-size=64
--param=l2-cache-size=9216 -mtune=skylake -fPIC -mmacosx-version-min=11.2.0

This seems to DTRT - I will try on some more machines as time permits.