When I'm working on PR112443, I notice there's some misoptimizations: after we fold _mm{,256}_blendv_epi8/pd/ps into gimple, the backend fails to combine it back to v{,p}blendv{v,ps,pd} since the pattern is too complicated, so I think maybe we should hanlde it in the gimple level.
The dump is like _1 = c_3(D) >= { 0, 0, 0, 0 }; _2 = VEC_COND_EXPR <_1, { -1, -1, -1, -1 }, { 0, 0, 0, 0 }>; _7 = VIEW_CONVERT_EXPR<vector(32) char>(_2); _8 = VIEW_CONVERT_EXPR<vector(32) char>(b_6(D)); _9 = VIEW_CONVERT_EXPR<vector(32) char>(a_5(D)); _10 = _7 < { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; _11 = VEC_COND_EXPR <_10, _8, _9>; It can be optimized to _6 = VIEW_CONVERT_EXPR<vector(32) char>(b_4(D)); _7 = VIEW_CONVERT_EXPR<vector(32) char>(a_3(D)); _10 = VIEW_CONVERT_EXPR<vector(32) char>(c_1(D)); _5 = _10 >= { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; _8 = VEC_COND_EXPR <_5, _6, _7>; _9 = VIEW_CONVERT_EXPR<__m256i>(_8); since _7 is either -1 or 0, _7 < 0 should is euqal to _1 = c_3(D) > { 0, 0, 0, 0 }; The patch add a gimple pattern to handle that. Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,} Ok for trunk? gcc/ChangeLog: * match.pd (VCE:(a cmp b ? -1 : 0) < 0) ? c : d ---> (VCE:a cmp VCE:b) ? c : d): New gimple simplication. gcc/testsuite/ChangeLog: * gcc.target/i386/avx512vl-blendv-3.c: New test. * gcc.target/i386/blendv-3.c: New test. --- gcc/match.pd | 17 +++++++ .../gcc.target/i386/avx512vl-blendv-3.c | 6 +++ gcc/testsuite/gcc.target/i386/blendv-3.c | 46 +++++++++++++++++++ 3 files changed, 69 insertions(+) create mode 100644 gcc/testsuite/gcc.target/i386/avx512vl-blendv-3.c create mode 100644 gcc/testsuite/gcc.target/i386/blendv-3.c diff --git a/gcc/match.pd b/gcc/match.pd index dbc811b2b38..e6f9c4fa1fd 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -5170,6 +5170,23 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (if (optimize_vectors_before_lowering_p () && types_match (@0, @3)) (vec_cond (bit_and @0 (bit_not @3)) @2 @1))) +(for cmp (simple_comparison) + (simplify + (vec_cond + (lt@4 (view_convert?@5 (vec_cond (cmp @0 @1) + integer_all_onesp + integer_zerop)) + integer_zerop) @2 @3) + (if (VECTOR_INTEGER_TYPE_P (TREE_TYPE (@0)) + && VECTOR_INTEGER_TYPE_P (TREE_TYPE (@5)) + && TYPE_SIGN (TREE_TYPE (@0)) == TYPE_SIGN (TREE_TYPE (@5)) + && VECTOR_TYPE_P (type)) + (with { + tree itype = TREE_TYPE (@5); + tree vbtype = TREE_TYPE (@4);} + (vec_cond (cmp:vbtype (view_convert:itype @0) + (view_convert:itype @1)) @2 @3))))) + /* c1 ? c2 ? a : b : b --> (c1 & c2) ? a : b */ (simplify (vec_cond @0 (vec_cond:s @1 @2 @3) @3) diff --git a/gcc/testsuite/gcc.target/i386/avx512vl-blendv-3.c b/gcc/testsuite/gcc.target/i386/avx512vl-blendv-3.c new file mode 100644 index 00000000000..2777e72ab5f --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/avx512vl-blendv-3.c @@ -0,0 +1,6 @@ +/* { dg-do compile } */ +/* { dg-options "-mavx512vl -mavx512bw -O2" } */ +/* { dg-final { scan-assembler-times {vp?blendv(?:b|p[sd])[ \t]*} 6 } } */ +/* { dg-final { scan-assembler-not {vpcmp} } } */ + +#include "blendv-3.c" diff --git a/gcc/testsuite/gcc.target/i386/blendv-3.c b/gcc/testsuite/gcc.target/i386/blendv-3.c new file mode 100644 index 00000000000..fa0fb067a73 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/blendv-3.c @@ -0,0 +1,46 @@ +/* { dg-do compile } */ +/* { dg-options "-mavx2 -O2" } */ +/* { dg-final { scan-assembler-times {vp?blendv(?:b|p[sd])[ \t]*} 6 } } */ +/* { dg-final { scan-assembler-not {vpcmp} } } */ + +#include <immintrin.h> + +__m256i +foo (__m256i a, __m256i b, __m256i c) +{ + return _mm256_blendv_epi8 (a, b, ~c < 0); +} + +__m256d +foo1 (__m256d a, __m256d b, __m256i c) +{ + __m256i d = ~c < 0; + return _mm256_blendv_pd (a, b, (__m256d)d); +} + +__m256 +foo2 (__m256 a, __m256 b, __m256i c) +{ + __m256i d = ~c < 0; + return _mm256_blendv_ps (a, b, (__m256)d); +} + +__m128i +foo4 (__m128i a, __m128i b, __m128i c) +{ + return _mm_blendv_epi8 (a, b, ~c < 0); +} + +__m128d +foo5 (__m128d a, __m128d b, __m128i c) +{ + __m128i d = ~c < 0; + return _mm_blendv_pd (a, b, (__m128d)d); +} + +__m128 +foo6 (__m128 a, __m128 b, __m128i c) +{ + __m128i d = ~c < 0; + return _mm_blendv_ps (a, b, (__m128)d); +} -- 2.31.1