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| author | Chen Li <meloli87@gmail.com> | 2015-12-12 01:04:15 +0000 |
|---|---|---|
| committer | Chen Li <meloli87@gmail.com> | 2015-12-12 01:04:15 +0000 |
| commit | 1b26b9ec9dabb9d0a2fefbbfc3b10449f20d0dd1 (patch) | |
| tree | e09416c5dc802ade3fab3a91428f829f17ac5f92 /clang/lib/CodeGen/CodeGenModule.cpp | |
| parent | 4d3da9c29b46fd605706c69cb4cddf2ec786af84 (diff) | |
| download | bcm5719-llvm-1b26b9ec9dabb9d0a2fefbbfc3b10449f20d0dd1.tar.gz bcm5719-llvm-1b26b9ec9dabb9d0a2fefbbfc3b10449f20d0dd1.zip | |
[X86ISelLowering] Add additional support for multiplication-to-shift conversion.
Summary: This patch adds support of conversion (mul x, 2^N + 1) => (add (shl x, N), x) and (mul x, 2^N - 1) => (sub (shl x, N), x) if the multiplication can not be converted to LEA + SHL or LEA + LEA. LLVM has already supported this on ARM, and it should also be useful on X86. Note the patch currently only applies to cases where the constant operand is positive, and I am planing to add another patch to support negative cases after this.
Reviewers: craig.topper, RKSimon
Subscribers: aemerson, llvm-commits
Differential Revision: http://reviews.llvm.org/D14603
llvm-svn: 255415
Diffstat (limited to 'clang/lib/CodeGen/CodeGenModule.cpp')
0 files changed, 0 insertions, 0 deletions
