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| author | Uros Bizjak <ubizjak@gmail.com> | 2021-06-11 12:31:42 +0200 |
|---|---|---|
| committer | Uros Bizjak <ubizjak@gmail.com> | 2021-06-11 12:32:40 +0200 |
| commit | 1fa991d1d74cb1ce96c48ede70ae0be7a9683ce3 (patch) | |
| tree | bc1ea9b598c736fa30bcd1faab10c94018a8ec09 /gcc/fold-const.c | |
| parent | 8bf728aecc4fea46b4490e950b9ae229f90597b0 (diff) | |
| download | gcc-1fa991d1d74cb1ce96c48ede70ae0be7a9683ce3.zip gcc-1fa991d1d74cb1ce96c48ede70ae0be7a9683ce3.tar.gz gcc-1fa991d1d74cb1ce96c48ede70ae0be7a9683ce3.tar.bz2 | |
i386: Try to avoid variable permutation instruction [PR101021]
Some permutations can be implemented without costly PSHUFB instruction, e.g.:
{ 8,9,10,11,12,13,14,15, 0,1,2,3,4,5,6,7 } with PALIGNR,
{ 0,1,2,3, 4,5,6,7, 4,5,6,7, 12,13,14,15 } with PSHUFD,
{ 0,1, 2,3, 2,3, 6,7, 8,9,10,11,12,13,14,15 } with PSHUFLW and
{ 0,1,2,3,4,5,6,7, 8,9, 10,11, 10,11, 14,15 } with PSHUFHW.
All these instructions have constant shuffle control mask and do not
need to load shuffle mask from a memory to a temporary XMM register.
2021-06-11 Uroš Bizjak <ubizjak@gmail.com>
gcc/
PR target/101021
* config/i386/i386-expand.c (expand_vec_perm_pshufb): Return
false if the permutation can be implemented with constant
permutation instruction in wider mode.
(canonicalize_vector_int_perm): Move above expand_vec_perm_pshufb.
Handle V8QImode and V4HImode.
gcc/testsuite/
PR target/101021
* gcc.target/i386/pr101021-1.c: New test.
* gcc.target/i386/pr101021-2.c: Ditto.
Diffstat (limited to 'gcc/fold-const.c')
0 files changed, 0 insertions, 0 deletions