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| author | Segher Boessenkool <segher@kernel.crashing.org> | 2017-05-19 13:29:21 +0200 |
|---|---|---|
| committer | Segher Boessenkool <segher@gcc.gnu.org> | 2017-05-19 13:29:21 +0200 |
| commit | 5d3ae76af134ab1f901f05223e57fc4ef951b18c (patch) | |
| tree | 58d1e883a54e2e25917097c06c8dd3dc265e9d50 | |
| parent | 3a6461f307f6204f2b415a3fc94fa21dc7cbe3ec (diff) | |
| download | gcc-5d3ae76af134ab1f901f05223e57fc4ef951b18c.zip gcc-5d3ae76af134ab1f901f05223e57fc4ef951b18c.tar.gz gcc-5d3ae76af134ab1f901f05223e57fc4ef951b18c.tar.bz2 | |
rs6000: Make constant formation a tiny bit better
If we cannot load a constant into a register in one insn, and that
constant is a valid mask (for rotate instructions), we currently
prefer to load -1 and then mask it. This patch makes us not do that if
instead we could use two add or or instructions, since those are
sometimes faster on certain CPUs (and never are slower).
* config/rs6000/rs6000.md (splitter to load of -1 and mask): Don't
use this splitter if two add or or instructions would also work for
the constant we want to generate.
From-SVN: r248265
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/config/rs6000/rs6000.md | 1 |
2 files changed, 7 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9e386f7..9006383 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2017-05-19 Segher Boessenkool <segher@kernel.crashing.org> + + * config/rs6000/rs6000.md (splitter to load of -1 and mask): Don't + use this splitter if two add or or instructions would also work for + the constant we want to generate. + 2017-05-19 Richard Biener <rguenther@suse.de> PR build/80821 diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md index 26baaaf..799d786 100644 --- a/gcc/config/rs6000/rs6000.md +++ b/gcc/config/rs6000/rs6000.md @@ -8732,6 +8732,7 @@ (match_operand:DI 1 "const_int_operand"))] "TARGET_POWERPC64 && num_insns_constant (operands[1], DImode) > 1 + && !IN_RANGE (INTVAL (operands[1]), -0x80000000, 0xffffffff) && rs6000_is_valid_and_mask (operands[1], DImode)" [(set (match_dup 0) (const_int -1)) |