Thumb has more 16-bit encoding space dedicated to ADD than ORR, allowing both a
3-address encoding and a wider range of immediates. So, particularly when
optimizing for code size (but it doesn't make things worse elsewhere) it's
beneficial to select an OR operation to an ADD if we know overflow won't occur.
This is made even better by LLVM's penchant for putting operations in canonical
form by converting the other way.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335119 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@329551 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@329160 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@321259 91177308-0d34-0410-b5e6-96231b3b80d8
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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318390 91177308-0d34-0410-b5e6-96231b3b80d8
