llvm-project

Commit Graph

Author	SHA1	Message	Date
Craig Topper	90317d1d94	[X86] Suppress load folding into and/or/xor if it will prevent matching btr/bts/btc. This is a follow up to r335753. At the time I forgot about isProfitableToFold which makes this pretty easy. Differential Revision: https://reviews.llvm.org/D48706 llvm-svn: 335895	2018-06-28 17:58:01 +00:00
Craig Topper	812fcb35e7	[X86] Use bts/btr/btc for single bit set/clear/complement of a variable bit position If we are just modifying a single bit at a variable bit position we can use the BT* instructions to make the change instead of shifting a 1(or rotating a -1) and doing a binop. These instruction also ignore the upper bits of their index input so we can also remove an and if one is present on the index. Fixes PR37938. llvm-svn: 335754	2018-06-27 16:47:39 +00:00
Craig Topper	069628b4df	[X86] Add test cases for D48606. llvm-svn: 335753	2018-06-27 16:47:36 +00:00

Author

SHA1

Message

Date

Craig Topper

90317d1d94

[X86] Suppress load folding into and/or/xor if it will prevent matching btr/bts/btc.

This is a follow up to r335753. At the time I forgot about isProfitableToFold which makes this pretty easy.

Differential Revision: https://reviews.llvm.org/D48706

llvm-svn: 335895

2018-06-28 17:58:01 +00:00

Craig Topper

812fcb35e7

[X86] Use bts/btr/btc for single bit set/clear/complement of a variable bit position

If we are just modifying a single bit at a variable bit position we can use the BT* instructions to make the change instead of shifting a 1(or rotating a -1) and doing a binop. These instruction also ignore the upper bits of their index input so we can also remove an and if one is present on the index.

Fixes PR37938.

llvm-svn: 335754

2018-06-27 16:47:39 +00:00

Craig Topper

069628b4df

[X86] Add test cases for D48606.

llvm-svn: 335753

2018-06-27 16:47:36 +00:00

3 Commits