Commit Graph

4 Commits

Author SHA1 Message Date
Hal Finkel 2edfbddcf0 Improve ext/trunc patterns on PPC64.
The PPC64 backend had patterns for i32 <-> i64 extensions and truncations that
would leave self-moves in the final assembly. Replacing those patterns with ones
based on the SUBREG builtins yields better-looking code.

Thanks to Jakob and Owen for their suggestions in this matter.

llvm-svn: 158283
2012-06-09 22:10:19 +00:00
Hal Finkel c6b5debb40 Enable PPC CTR loop formation by default.
Thanks to Jakob's help, this now causes no new test suite failures!

Over the entire test suite, this gives an average 1% speedup. The largest speedups are:
SingleSource/Benchmarks/Misc/pi - 108%
SingleSource/Benchmarks/CoyoteBench/lpbench - 54%
MultiSource/Benchmarks/Prolangs-C/unix-smail/unix-smail - 50%
SingleSource/Benchmarks/Shootout/ary3 - 32%
SingleSource/Benchmarks/Shootout-C++/matrix - 30%

The largest slowdowns are:
MultiSource/Benchmarks/mediabench/gsm/toast/toast - -30%
MultiSource/Benchmarks/Prolangs-C/bison/mybison - -25%
MultiSource/Benchmarks/BitBench/uuencode/uuencode - -22%
MultiSource/Applications/d/make_dparser - -14%
SingleSource/Benchmarks/Shootout-C++/ary - -13%

In light of these slowdowns, additional profiling work is obviously needed!

llvm-svn: 158223
2012-06-08 19:19:53 +00:00
Hal Finkel 821e00121c Disable the PPC CTR-Loops pass by default.
The pass itself works well, but the something in the Machine* infrastructure
does not understand terminators which define registers. Without the ability
to use the block-placement pass, etc. this causes performance regressions (and
so is turned off by default). Turning off the analysis turns off the problems
with the Machine* infrastructure.

llvm-svn: 158206
2012-06-08 15:38:25 +00:00
Hal Finkel 96c2d4d945 Add the PPCCTRLoops pass: a PPC machine-code-level optimization pass to form CTR-based loop branching code.
This pass is derived from the Hexagon HardwareLoops pass. The only significant enhancement over the Hexagon
pass is that PPCCTRLoops will also attempt to delete the replaced add and compare operations if they are
no longer otherwise used. Also, invalid preheader DebugLoc is not used.

llvm-svn: 158204
2012-06-08 15:38:21 +00:00