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| author | Roger Sayle <roger@nextmovesoftware.com> | 2022-08-15 17:43:02 +0100 |
|---|---|---|
| committer | Roger Sayle <roger@nextmovesoftware.com> | 2022-08-15 17:43:02 +0100 |
| commit | 6f94923dea21bd92ba2fc40c4a3be509bb1b7f0c (patch) | |
| tree | 633282879b2abf151ccebb0aba885d3cc9d36370 | |
| parent | 418b71c0d535bf91df78bad2e198c57934682eaa (diff) | |
| download | gcc-6f94923dea21bd92ba2fc40c4a3be509bb1b7f0c.zip gcc-6f94923dea21bd92ba2fc40c4a3be509bb1b7f0c.tar.gz gcc-6f94923dea21bd92ba2fc40c4a3be509bb1b7f0c.tar.bz2 | |
Improved gain calculation for COMPARE to 0 or -1 in TImode STV on x86_64.
This patch tweaks timode_scalar_chain::compute_convert_gain to provide
more accurate costs for converting TImode comparisons against zero or
minus 1 to V1TImode equivalents.
2022-08-15 Roger Sayle <roger@nextmovesoftware.com>
gcc/ChangeLog
* config/i386/i386-features.cc
(timode_scalar_chain::compute_convert_gain): Provide gains for
comparisons against 0/-1, including "*testti" patterns.
| -rw-r--r-- | gcc/config/i386/i386-features.cc | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/gcc/config/i386/i386-features.cc b/gcc/config/i386/i386-features.cc index effc2f2..28914de 100644 --- a/gcc/config/i386/i386-features.cc +++ b/gcc/config/i386/i386-features.cc @@ -1250,6 +1250,23 @@ timode_scalar_chain::compute_convert_gain () : COSTS_N_INSNS (1); break; + case COMPARE: + if (XEXP (src, 1) == const0_rtx) + { + if (GET_CODE (XEXP (src, 0)) == AND) + /* and;and;or (9 bytes) vs. ptest (5 bytes). */ + igain = optimize_insn_for_size_p() ? COSTS_N_BYTES (4) + : COSTS_N_INSNS (2); + /* or (3 bytes) vs. ptest (5 bytes). */ + else if (optimize_insn_for_size_p ()) + igain = -COSTS_N_BYTES (2); + } + else if (XEXP (src, 1) == const1_rtx) + /* and;cmp -1 (7 bytes) vs. pcmpeqd;pxor;ptest (13 bytes). */ + igain = optimize_insn_for_size_p() ? -COSTS_N_BYTES (6) + : -COSTS_N_INSNS (1); + break; + default: break; } |