llvm-6502/lib/Transforms
Shuxin Yang b1ccfb3a54 [Fast-math] Disable "(C1/X)*C2 => (C1*C2)/X" if C1/X has multiple uses.
If "C1/X" were having multiple uses, the only benefit of this
transformation is to potentially shorten critical path. But it is at the
cost of instroducing additional div.

  The additional div may or may not incur cost depending on how div is
implemented. If it is implemented using Newton–Raphson iteration, it dosen't
seem to incur any cost (FIXME). However, if the div blocks the entire
pipeline, that sounds to be pretty expensive. Let CodeGen to take care 
this transformation.

  This patch sees 6% on a benchmark.

rdar://15032743


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191037 91177308-0d34-0410-b5e6-96231b3b80d8
2013-09-19 21:13:46 +00:00
..
Hello
InstCombine [Fast-math] Disable "(C1/X)*C2 => (C1*C2)/X" if C1/X has multiple uses. 2013-09-19 21:13:46 +00:00
Instrumentation [msan] Wrap indirect functions. 2013-09-19 15:22:35 +00:00
IPO Bugfix for PR17099: 2013-09-17 09:36:11 +00:00
ObjCARC Revert "Give internal classes hidden visibility." 2013-09-11 18:05:11 +00:00
Scalar GVN proceeds in the presence of dead code. 2013-09-19 17:22:51 +00:00
Utils Replace some unnecessary vector copies with references. 2013-09-15 22:04:42 +00:00
Vectorize Prevent LoopVectorizer and SLPVectorizer running if the target has no vector registers. 2013-09-18 12:43:35 +00:00
CMakeLists.txt
LLVMBuild.txt
Makefile