Commit Graph

9 Commits

Author SHA1 Message Date
Sam Parker 1f4f4d9a08 [DAGCombine] Improve ReduceLoad for SRL
Recommitting r329283, third time lucky...

If the SRL node is only used by an AND, we may be able to set the
ExtVT to the width of the mask, making the AND redundant. To support
this, another check has been added in isLegalNarrowLoad which queries
whether the load is valid.

Differential Revision: https://reviews.llvm.org/D41350

llvm-svn: 329551
2018-04-09 08:16:11 +00:00
Sam Parker 0e7deb8104 [DAGCombine] Revert r329160
Again, broke the big endian stage 2 builders.

llvm-svn: 329283
2018-04-05 13:46:17 +00:00
Sam Parker 7ec722d603 [DAGCombine] Improve ReduceLoadWidth for SRL
Recommitting rL321259. Previosuly this caused an issue with PPCBE but
I didn't receieve a reproducer and didn't have the time to follow up.
If the issue appears again, please provide a reproducer so I can fix
it.

Original commit message:

If the SRL node is only used by an AND, we may be able to set the
ExtVT to the width of the mask, making the AND redundant. To support
this, another check has been added in isLegalNarrowLoad which queries
whether the load is valid.

Differential Revision: https://reviews.llvm.org/D41350

llvm-svn: 329160
2018-04-04 09:26:56 +00:00
Sam Parker cf426fccd4 [DAGCombine] Revert r321259
Improve ReduceLoadWidth for SRL Patch is causing an issue on the
PPC64 BE santizer.

llvm-svn: 321349
2017-12-22 08:36:25 +00:00
Sam Parker 59efb8cb5b [DAGCombine] Improve ReduceLoadWidth for SRL
If the SRL node is only used by an AND, we may be able to set the
ExtVT to the width of the mask, making the AND redundant. To support
this, another check has been added in isLegalNarrowLoad which queries
whether the load is valid.

Differential Revision: https://reviews.llvm.org/D41350

llvm-svn: 321259
2017-12-21 12:55:04 +00:00
Sam Parker fd967f2f7a [ARM] Adjust test checks
Correct the CHECK-LABELS of a couple of dag combine tests.

llvm-svn: 320963
2017-12-18 10:08:03 +00:00
Sam Parker 18b0d1e5b9 [ARM] Some DAG combine tests
Add some more and and shift load combine tests.

llvm-svn: 320822
2017-12-15 15:30:39 +00:00
Sam Parker 43fa5911a1 [DAGCombine] Enable more srl -> load combines
Change the calculation for the desired ValueType for non-sign
extending loads, as in those cases we don't care about the
higher bits. This creates a smaller ExtVT and allows for such
combinations as:
(srl (zextload i16, [addr]), 8) -> (zextload i8, [addr + 1])

Differential Revision: https://reviews.llvm.org/D40034

llvm-svn: 318390
2017-11-16 11:28:26 +00:00
Zijiao Ma bf6007bd1b Make the canonicalisation on shifts benifit to more case.
1.Fix pessimized case in FIXME.
2.Add tests for it.
3.The canonicalisation on shifts results in different sequence for
  tests of machine-licm.Correct some check lines.

Differential Revision: https://reviews.llvm.org/D27916

llvm-svn: 290410
2016-12-23 02:56:07 +00:00