Evan Cheng 79590b8edf Instcombine was transforming: ...

%shr = lshr i64 %key, 3
  %0 = load i64* %val, align 8
  %sub = add i64 %0, -1
  %and = and i64 %sub, %shr
  ret i64 %and

to:
  %shr = lshr i64 %key, 3
  %0 = load i64* %val, align 8
  %sub = add i64 %0, 2305843009213693951
  %and = and i64 %sub, %shr
  ret i64 %and

The demanded bit optimization is actually a pessimization because add -1 would
be codegen'ed as a sub 1. Teach the demanded constant shrinking optimization
to check for negated constant to make sure it is actually reducing the width
of the constant.

rdar://11793464


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160101 91177308-0d34-0410-b5e6-96231b3b80d8

2012-07-12 01:45:35 +00:00

..

CMakeLists.txt

llvm/lib: [CMake] Add explicit dependency to intrinsics_gen.

2012-06-24 13:32:01 +00:00

InstCombine.h

instcombine: merge the functions that remove dead allocas and dead mallocs/callocs/...

2012-07-09 18:38:20 +00:00

InstCombineAddSub.cpp

Remove a instcombine transform that (no longer?) makes sense:

2012-06-26 22:03:13 +00:00

InstCombineAndOrXor.cpp

InstCombine: fix a bug when combining (fcmp cc0 x, y) && (fcmp cc1 x, y).

2012-06-14 05:57:42 +00:00

InstCombineCalls.cpp

instcombine: merge the functions that remove dead allocas and dead mallocs/callocs/...

2012-07-09 18:38:20 +00:00

InstCombineCasts.cpp

Revert remaining part of r93200: "Disable folding sext(trunc(x)) -> x"

2012-06-22 16:36:43 +00:00

InstCombineCompares.cpp

InstCombine: factor code better.

2012-06-11 08:01:25 +00:00

InstCombineLoadStoreAlloca.cpp

instcombine: merge the functions that remove dead allocas and dead mallocs/callocs/...

2012-07-09 18:38:20 +00:00

InstCombineMulDivRem.cpp

Look pass zext to strength reduce an udiv. Patch by David Majnemer. rdar://11721329

2012-06-21 22:52:49 +00:00

InstCombinePHI.cpp

…

InstCombineSelect.cpp

Fix a bug in FoldSelectOpOp. Bitcast ops may change the number of vector elements, which may disagree with the select condition type.

2012-06-07 20:28:57 +00:00

InstCombineShifts.cpp

PR12967: Don't crash when trying to fold a shift that's larger than the type's size.

2012-05-27 22:03:32 +00:00

InstCombineSimplifyDemanded.cpp

Instcombine was transforming:

2012-07-12 01:45:35 +00:00

InstCombineVectorOps.cpp

…

InstCombineWorklist.h

Use an iterator instead of calling .size() on the worklist every time, which is wasteful.

2012-03-15 11:19:41 +00:00

InstructionCombining.cpp

instcombine: merge the functions that remove dead allocas and dead mallocs/callocs/...

2012-07-09 18:38:20 +00:00

LLVMBuild.txt

…

Makefile

…