[Bug libgcc/108279] Improved speed for float128 routines

[already5chosen at yahoo dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108279

--- Comment #11 from Michael_S <already5chosen at yahoo dot com> ---
(In reply to Thomas Koenig from comment #9)
> Created attachment 54273 [details]
> matmul_r16.i
> 
> Here is matmul_r16.i from a relatively recent trunk.

Thank you.
Unfortunately, I was not able to link it with main in Fortran.
So, I still only have to guess why even after replacement of __multf3 and
__addtf3 by my implementations it is still more than twice slower (on Zen3)
then what it should be.
Looking at source and assuming that inner loop starts at line 8944, this
loop looks very strange, but apart from bad programming style and apart from
misunderstanding of what is optimal scheduling there is nothing criminal about
it. May be, because of wrong scheduling, it is 10-15% slower than the best, but
certainly it should not be 2.4 times slower that I am seeing.


That's what I got from linker:
/usr/bin/ld: matmul_r16.o: warning: relocation against
`_gfortrani_matmul_r16_avx128_fma3' in read-only section `.text'
/usr/bin/ld: matmul_r16.o: in function `matmul_r16_avx':
matmul_r16.c:(.text+0x48): undefined reference to `_gfortrani_compile_options'
/usr/bin/ld: matmul_r16.c:(.text+0x342): undefined reference to
`_gfortrani_compile_options'
/usr/bin/ld: matmul_r16.c:(.text+0x10e4): undefined reference to
`_gfortrani_size0'
/usr/bin/ld: matmul_r16.c:(.text+0x10f1): undefined reference to
`_gfortrani_xmallocarray'
/usr/bin/ld: matmul_r16.c:(.text+0x12e5): undefined reference to
`_gfortrani_runtime_error'
/usr/bin/ld: matmul_r16.c:(.text+0x13a9): undefined reference to
`_gfortrani_runtime_error'
/usr/bin/ld: matmul_r16.c:(.text+0x13e7): undefined reference to
`_gfortrani_runtime_error'
/usr/bin/ld: matmul_r16.o: in function `matmul_r16_avx2':
matmul_r16.c:(.text+0x24c8): undefined reference to
`_gfortrani_compile_options'
/usr/bin/ld: matmul_r16.c:(.text+0x27c2): undefined reference to
`_gfortrani_compile_options'
/usr/bin/ld: matmul_r16.c:(.text+0x3564): undefined reference to
`_gfortrani_size0'
/usr/bin/ld: matmul_r16.c:(.text+0x3571): undefined reference to
`_gfortrani_xmallocarray'
/usr/bin/ld: matmul_r16.c:(.text+0x3765): undefined reference to
`_gfortrani_runtime_error'
/usr/bin/ld: matmul_r16.c:(.text+0x3829): undefined reference to
`_gfortrani_runtime_error'
/usr/bin/ld: matmul_r16.c:(.text+0x3867): undefined reference to
`_gfortrani_runtime_error'
/usr/bin/ld: matmul_r16.o: in function `matmul_r16_avx512f':
matmul_r16.c:(.text+0x4948): undefined reference to
`_gfortrani_compile_options'
/usr/bin/ld: matmul_r16.c:(.text+0x4c47): undefined reference to
`_gfortrani_compile_options'
/usr/bin/ld: matmul_r16.c:(.text+0x5a32): undefined reference to
`_gfortrani_size0'
/usr/bin/ld: matmul_r16.c:(.text+0x5a3f): undefined reference to
`_gfortrani_xmallocarray'
/usr/bin/ld: matmul_r16.c:(.text+0x5c35): undefined reference to
`_gfortrani_runtime_error'
/usr/bin/ld: matmul_r16.c:(.text+0x5cfb): undefined reference to
`_gfortrani_runtime_error'
/usr/bin/ld: matmul_r16.c:(.text+0x5d35): undefined reference to
`_gfortrani_runtime_error'
/usr/bin/ld: matmul_r16.o: in function `matmul_r16_vanilla':
matmul_r16.c:(.text+0x6de8): undefined reference to
`_gfortrani_compile_options'
/usr/bin/ld: matmul_r16.c:(.text+0x70e2): undefined reference to
`_gfortrani_compile_options'
/usr/bin/ld: matmul_r16.c:(.text+0x7e84): undefined reference to
`_gfortrani_size0'
/usr/bin/ld: matmul_r16.c:(.text+0x7e91): undefined reference to
`_gfortrani_xmallocarray'
/usr/bin/ld: matmul_r16.c:(.text+0x8085): undefined reference to
`_gfortrani_runtime_error'
/usr/bin/ld: matmul_r16.c:(.text+0x8149): undefined reference to
`_gfortrani_runtime_error'
/usr/bin/ld: matmul_r16.c:(.text+0x8187): undefined reference to
`_gfortrani_runtime_error'
/usr/bin/ld: matmul_r16.o: in function `_gfortran_matmul_r16':
matmul_r16.c:(.text+0x92b7): undefined reference to
`_gfortrani_matmul_r16_avx128_fma3'
/usr/bin/ld: matmul_r16.c:(.text+0x92ea): undefined reference to
`_gfortrani_matmul_r16_avx128_fma4'
/usr/bin/ld: warning: creating DT_TEXTREL in a PIE
collect2: error: ld returned 1 exit status