Duncan Sands 593faa53fa My auto-simplifier noticed that ((X/Y)*Y)/Y occurs several times in SPEC ... benchmarks, and that it can be simplified to X/Y. (In general you can only simplify (Z*Y)/Y to Z if the multiplication did not overflow; if Z has the form "X/Y" then this is the case). This patch implements that transform and moves some Div logic out of instcombine and into InstructionSimplify. Unfortunately instcombine gets in the way somewhat, since it likes to change (X/Y)*Y into X-(X rem Y), so I had to teach instcombine about this too. Finally, thanks to the NSW/NUW flags, sometimes we know directly that "Z*Y" does not overflow, because the flag says so, so I added that logic too. This eliminates a bunch of divisions and subtractions in 447.dealII, and has good effects on some other benchmarks too. It seems to have quite an effect on tramp3d-v4 but it's hard to say if it's good or bad because inlining decisions changed, resulting in massive changes all over. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124487 91177308-0d34-0410-b5e6-96231b3b80d8		2011-01-28 16:51:11 +00:00
..
CMakeLists.txt	Removed a bunch of unnecessary target_link_libraries.	2010-09-28 22:39:14 +00:00
InstCombine.h	remove the AllowAggressive argument to FoldOpIntoPhi. It is forced to false in the	2011-01-16 05:14:26 +00:00
InstCombineAddSub.cpp	one more instcombine variant that is needed to work with future changes,	2011-01-15 05:50:18 +00:00
InstCombineAndOrXor.cpp	Just because we have determined that an (fcmp | fcmp) is true for A < B,	2011-01-21 19:39:42 +00:00
InstCombineCalls.cpp	Teach instcombine about the rest of the SSE and SSE2 conversion	2011-01-10 07:19:37 +00:00
InstCombineCasts.cpp	implement an instcombine xform that canonicalizes casts outside of and-with-constant operations.	2011-01-15 06:32:33 +00:00
InstCombineCompares.cpp	At -O123 the early-cse pass is run before instcombine has run. According to my	2011-01-20 13:21:55 +00:00
InstCombineLoadStoreAlloca.cpp	Move getOrEnforceKnownAlignment out of instcombine into Transforms/Utils.	2010-12-25 20:37:57 +00:00
InstCombineMulDivRem.cpp	My auto-simplifier noticed that ((X/Y)*Y)/Y occurs several times in SPEC	2011-01-28 16:51:11 +00:00
InstCombinePHI.cpp	Teach InstructionSimplify about phi nodes. I chose to have it simply	2010-11-14 13:30:18 +00:00
InstCombineSelect.cpp	Fold select + select where both selects are on the same condition.	2011-01-28 03:28:10 +00:00
InstCombineShifts.cpp	Null initialize a few variables flagged by	2011-01-23 17:05:06 +00:00
InstCombineSimplifyDemanded.cpp	PR5207: Change APInt methods trunc(), sext(), zext(), sextOrTrunc() and	2010-12-07 08:25:19 +00:00
InstCombineVectorOps.cpp	PR5207: Rename overloaded APInt methods set(), clear(), flip() to	2010-12-01 08:53:58 +00:00
InstCombineWorklist.h	I got tired of VISIBILITY_HIDDEN colliding with the gcc enum. Rename it	2010-05-11 20:16:09 +00:00
InstructionCombining.cpp	fix PR9013, an infinite loop in instcombine.	2011-01-21 05:29:50 +00:00
Makefile	make -fno-rtti the default unless a directory builds with REQUIRES_RTTI.	2010-01-24 20:43:08 +00:00