diff options
| author | Florian Hahn <flo@fhahn.com> | 2022-07-28 10:02:19 +0100 |
|---|---|---|
| committer | Florian Hahn <flo@fhahn.com> | 2022-07-28 10:02:19 +0100 |
| commit | 8daa338297d533db4d1ae8d3770613eb25c29688 (patch) | |
| tree | a071b1d78bf74fcac8e35beca0851e676d260ad9 /lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.h | |
| parent | 6f6c40a875c84443f255f3a6b4efc0bc0f2fb67a (diff) | |
| download | llvm-8daa338297d533db4d1ae8d3770613eb25c29688.zip llvm-8daa338297d533db4d1ae8d3770613eb25c29688.tar.gz llvm-8daa338297d533db4d1ae8d3770613eb25c29688.tar.bz2 | |
[SCEV] Avoid repeated proveNoUnsignedWrapViaInduction calls.
At the moment, proveNoUnsignedWrapViaInduction may be called for the
same AddRec a large number of times via getZeroExtendExpr. This can have
a severe compile-time impact for very loop-heavy code. One one
particular workload, LSR takes ~51s without this patch, almost
exlusively in proveNoUnsignedWrapViaInduction. With this patch, the time
in LSR drops to ~0.4s.
If proveNoUnsignedWrapViaInduction failed to prove NUW the first time,
it is unlikely to succeed on subsequent tries and the cost doesn't seem
to be justified.
Besides drastically improving compile-time in some excessive cases, this
also has a slightly positive compile-time impact on CTMark:
NewPM-O3: -0.07%
NewPM-ReleaseThinLTO: -0.08%
NewPM-ReleaseLTO-g: -0.06
https://llvm-compile-time-tracker.com/compare.php?from=b435da027d7774c24cdb8c88d09f6b771e07fb14&to=f2729e33e8284b502f6c35a43345272252f35d12&stat=instructions
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D130648
Diffstat (limited to 'lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.h')
0 files changed, 0 insertions, 0 deletions