mirror/gcc
1
0
Fork 0
mirror of https://github.com/gcc-mirror/gcc.git synced 2024-11-21 13:40:47 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Add X86_TUNE_AVX512_TWO_EPILOGUES, enable for Zen4 and Zen5

Browse Source 
The following adds X86_TUNE_AVX512_TWO_EPILOGUES tuning and directs the
vectorizer to produce both a vector AVX2 and SSE epilogue for AVX512
vectorized loops when set.  The tuning is enabled by default for Zen4
and Zen5 where I benchmarked it to be overall positive on SPEC CPU 2017 both
in performance and overall code size.  In particular it speeds up
525.x264_r which with only an AVX2 epilogue ends up in unvectorized code
at the moment.

	* config/i386/i386.cc (ix86_vector_costs::finish_cost): Set
	m_suggested_epilogue_mode according to X86_TUNE_AVX512_TWO_EPILOGUES.
	* config/i386/x86-tune.def (X86_TUNE_AVX512_TWO_EPILOGUES): Add.
	Enable for znver4 and znver5.
This commit is contained in:
Richard Biener 2024-11-08 11:17:22 +01:00 committed by Richard Biener
parent 82d955b0a8
commit 9a62c14958
2 changed files with 17 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
gcc/config/i386/i386.cc
View File

@ -25353,6 +25353,18 @@ ix86_vector_costs::finish_cost (const vector_costs *scalar_costs)
&& TARGET_AVX256_AVOID_VEC_PERM)
m_costs[i] = INT_MAX;
/* When X86_TUNE_AVX512_TWO_EPILOGUES is enabled arrange for both
a AVX2 and a SSE epilogue for AVX512 vectorized loops. */
if (loop_vinfo
&& ix86_tune_features[X86_TUNE_AVX512_TWO_EPILOGUES])
{
if (GET_MODE_SIZE (loop_vinfo->vector_mode) == 64)
m_suggested_epilogue_mode = V32QImode;
else if (LOOP_VINFO_EPILOGUE_P (loop_vinfo)
&& GET_MODE_SIZE (loop_vinfo->vector_mode) == 32)
m_suggested_epilogue_mode = V16QImode;
}
vector_costs::finish_cost (scalar_costs);
}

5
gcc/config/i386/x86-tune.def
View File

@ -597,6 +597,11 @@ DEF_TUNE (X86_TUNE_AVX512_MOVE_BY_PIECES, "avx512_move_by_pieces",
DEF_TUNE (X86_TUNE_AVX512_STORE_BY_PIECES, "avx512_store_by_pieces",
m_SAPPHIRERAPIDS | m_ZNVER4 | m_ZNVER5)
/* X86_TUNE_AVX512_TWO_EPILOGUES: Use two vector epilogues for 512-bit
vectorized loops. */
DEF_TUNE (X86_TUNE_AVX512_TWO_EPILOGUES, "avx512_two_epilogues",
m_ZNVER4 | m_ZNVER5)
/*****************************************************************************/
/*****************************************************************************/
/* Historical relics: tuning flags that helps a specific old CPU designs */