Sanjay Patel ac3951a735 [AggressiveInstCombine] convert a chain of 'and-shift' bits into masked compare ...

This is a follow-up to D45986. As suggested there, we should match the "all-bits-set" 
pattern in addition to "any-bits-set".

This was a little more complicated than I thought it would be initially because the 
"and 1" instruction can be anywhere in the chain. Hopefully, the code comments make 
that logic understandable, but if you see a way to simplify or improve that, it's 
most appreciated.

This transforms patterns that emerge from bitfield tests as seen in PR37098:
https://bugs.llvm.org/show_bug.cgi?id=37098

I think it would also help reduce the large test from:
D46336
D46595 
but we need something to reassociate that case to the forms we're expecting here first.

Differential Revision: https://reviews.llvm.org/D46649

llvm-svn: 331937

2018-05-09 23:08:15 +00:00

..

AggressiveInstCombine.cpp

[AggressiveInstCombine] convert a chain of 'and-shift' bits into masked compare

2018-05-09 23:08:15 +00:00

AggressiveInstCombineInternal.h

Remove unused header to fix layering.

2018-03-29 22:35:59 +00:00

CMakeLists.txt

Another try to commit 323321 (aggressive instruction combine).

2018-01-25 12:06:32 +00:00

LLVMBuild.txt

Another try to commit 323321 (aggressive instruction combine).

2018-01-25 12:06:32 +00:00

TruncInstCombine.cpp

[AggressiveInstCombine] Use use_empty() instead of !getNumUses(), NFC

2018-03-02 23:22:49 +00:00