llvm-project/llvm
Alina Sbirlea 2312a06c87 [SCEV] Add option to forget everything in SCEV.
Summary:
Create a method to forget everything in SCEV.
Add a cl::opt and PassManagerBuilder option to use this in LoopUnroll.

Motivation: Certain Halide applications spend a very long time compiling in forgetLoop, and prefer to forget everything and rebuild SCEV from scratch.
Sample difference in compile time reduction: 21.04 to 14.78 using current ToT release build.
Testcase showcasing this cannot be opensourced and is fairly large.

The option disabled by default, but it may be desirable to enable by
default. Evidence in favor (two difference runs on different days/ToT state):

File Before (s) After (s)
clang-9.bc 7267.91 6639.14
llvm-as.bc 194.12 194.12
llvm-dis.bc 62.50 62.50
opt.bc 1855.85 1857.53

File Before (s) After (s)
clang-9.bc 8588.70 7812.83
llvm-as.bc 196.20 194.78
llvm-dis.bc 61.55 61.97
opt.bc 1739.78 1886.26

Reviewers: sanjoy

Subscribers: mehdi_amini, jlebar, zzheng, javed.absar, dmgreen, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60144

llvm-svn: 358304
2019-04-12 19:16:07 +00:00
..
benchmarks
bindings [LLVM-C] Correct The Current Debug Location Accessors (Again) 2019-04-10 14:19:05 +00:00
cmake [cmake] Fix dependency issue in TableGen 2019-04-11 21:05:15 +00:00
docs [PDB Docs] Add some prose describing public and global symbols. 2019-04-12 15:51:40 +00:00
examples
include [SCEV] Add option to forget everything in SCEV. 2019-04-12 19:16:07 +00:00
lib [SCEV] Add option to forget everything in SCEV. 2019-04-12 19:16:07 +00:00
projects
resources
runtimes [runtime] Use --strip-all rather than --strip-sections 2019-03-10 04:26:54 +00:00
test [MemorySSA] Small fix for the clobber limit. 2019-04-12 18:48:46 +00:00
tools Simplify decoupling between RuntimeDyld/RuntimeDyldChecker, add 'got_addr' util. 2019-04-12 18:07:28 +00:00
unittests [SCEV] Add option to forget everything in SCEV. 2019-04-12 19:16:07 +00:00
utils [llvm] [lit] Add target-x86* features 2019-04-11 14:58:39 +00:00
.arcconfig
.clang-format
.clang-tidy
.gitattributes
.gitignore
CMakeLists.txt [CMake] Move configuration of LLVM_CXX_STD to HandleLLVMOptions.cmake 2019-04-09 08:14:32 +00:00
CODE_OWNERS.TXT
CREDITS.TXT
LICENSE.TXT
LLVMBuild.txt
README.txt
RELEASE_TESTERS.TXT
configure
llvm.spec.in

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