Louis Gerbarg 2d1fa5f718 Add support for combining GEPs across PHI nodes ...

Currently LLVM will generally merge GEPs. This allows backends to use more
complex addressing modes. In some cases this is not happening because there
is PHI inbetween the two GEPs:

  GEP1--\
        |-->PHI1-->GEP3
  GEP2--/

This patch checks to see if GEP1 and GEP2 are similiar enough that they can be
cloned (GEP12) in GEP3's BB, allowing GEP->GEP merging (GEP123):

  GEP1--\                     --\                           --\
        |-->PHI1-->GEP3  ==>    |-->PHI2->GEP12->GEP3 == >    |-->PHI2->GEP123
  GEP2--/                     --/                           --/

This also breaks certain use chains that are preventing GEP->GEP merges that the
the existing instcombine would merge otherwise.

Tests included.

rdar://15547484

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209049 91177308-0d34-0410-b5e6-96231b3b80d8

2014-05-16 23:47:24 +00:00

..

CMakeLists.txt

Tidy up a bit. No functional change.

2013-04-05 21:20:12 +00:00

InstCombine.h

Rename ComputeMaskedBits to computeKnownBits. "Masked" has been

2014-05-14 21:14:37 +00:00

InstCombineAddSub.cpp

Rename ComputeMaskedBits to computeKnownBits. "Masked" has been

2014-05-14 21:14:37 +00:00

InstCombineAndOrXor.cpp

Reorder shuffle and binary operation.

2014-05-11 08:46:12 +00:00

InstCombineCalls.cpp

Rename ComputeMaskedBits to computeKnownBits. "Masked" has been

2014-05-14 21:14:37 +00:00

InstCombineCasts.cpp

Rename ComputeMaskedBits to computeKnownBits. "Masked" has been

2014-05-14 21:14:37 +00:00

InstCombineCompares.cpp

InstCombine: Optimize -x s< cst

2014-05-15 00:02:20 +00:00

InstCombineLoadStoreAlloca.cpp

[C++] Use 'nullptr'. Transforms edition.

2014-04-25 05:29:35 +00:00

InstCombineMulDivRem.cpp

Optimize integral reciprocal (udiv 1, x and sdiv 1, x) to not use division. This fires exactly once in a clang bootstrap, but covers a few different results from http://www.cs.utah.edu/~regehr/souper/

2014-05-14 03:03:05 +00:00

InstCombinePHI.cpp

[C++] Use 'nullptr'. Transforms edition.

2014-04-25 05:29:35 +00:00

InstCombineSelect.cpp

Reverting r208848, reason: build failure: sanitizer-x86_64-linux-bootstrap/builds/3399

2014-05-15 08:22:55 +00:00

InstCombineShifts.cpp

Reorder shuffle and binary operation.

2014-05-11 08:46:12 +00:00

InstCombineSimplifyDemanded.cpp

Rename ComputeMaskedBits to computeKnownBits. "Masked" has been

2014-05-14 21:14:37 +00:00

InstCombineVectorOps.cpp

Fix type of shuffle resulted from shuffle merge.

2014-05-13 06:07:21 +00:00

InstCombineWorklist.h

[C++] Use 'nullptr'.

2014-04-28 04:05:08 +00:00

InstructionCombining.cpp

Add support for combining GEPs across PHI nodes

2014-05-16 23:47:24 +00:00

LLVMBuild.txt

LLVMBuild: Remove trailing newline, which irked me.

2011-12-12 19:48:00 +00:00

Makefile

make -fno-rtti the default unless a directory builds with REQUIRES_RTTI.

2010-01-24 20:43:08 +00:00