commit	9530f1886433d77bc203c366915a9ab3160c7efc	[log] [tgz]
author	Sanjay Patel <spatel@rotateright.com>	Sun Jan 21 16:14:51 2018 +0000
committer	Sanjay Patel <spatel@rotateright.com>	Sun Jan 21 16:14:51 2018 +0000
tree	7713b04c77141e282a864a0e30e243e64ab4a143
parent	7a44e4d594c98b5998ebffc041490564953a3cb8 [diff]

[InstCombine] (X << Y) / X -> 1 << Y

...when the shift is known to not overflow with the matching
signed-ness of the division.

This closes an optimization gap caused by canonicalizing mul
by power-of-2 to shl as shown in PR35709:
https://bugs.llvm.org/show_bug.cgi?id=35709

Patch by Anton Bikineev!

Differential Revision: https://reviews.llvm.org/D42032

llvm-svn: 323068

llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp[diff]
llvm/test/Transforms/InstCombine/div-shift.ll[diff]

2 files changed

tree: 7713b04c77141e282a864a0e30e243e64ab4a143

clang/
clang-tools-extra/
compiler-rt/
debuginfo-tests/
libclc/
libcxx/
libcxxabi/
libunwind/
lld/
lldb/
llgo/
llvm/
openmp/
parallel-libs/
polly/
README.md

README.md

Low Level Virtual Machine (LLVM)

This directory and its subdirectories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and runtime environments.