[CVP] Handle instructions with no user. No need to create CVPLattice state. This handles terminator instructions and more.
Summary:
I tested this patch by compiling sqlite3.ll (clang -O3 -mllvm -disable-llvm-optzns sqlite3.c.)
opt -called-value-propagation sqlite3.ll -time-passes -f -o out.ll
I get 10+% speedup for the pass. I expect some of the gain come from skipping terminator instructions.
=== BEFORE THE PATCH ===
===-------------------------------------------------------------------------===
... Pass execution timing report ...
===-------------------------------------------------------------------------===
Total Execution Time: 0.5562 seconds (0.5582 wall clock)
---User Time--- --System Time-- --User+System-- ---Wall Time--- --- Name ---
0.2485 ( 46.4%) 0.0120 ( 57.7%) 0.2605 ( 46.8%) 0.2615 ( 46.8%) Bitcode Writer
0.1607 ( 30.0%) 0.0079 ( 37.7%) 0.1685 ( 30.3%) 0.1693 ( 30.3%) Called Value Propagation
0.1262 ( 23.6%) 0.0009 ( 4.5%) 0.1271 ( 22.9%) 0.1275 ( 22.8%) Module Verifier
0.5353 (100.0%) 0.0209 (100.0%) 0.5562 (100.0%) 0.5582 (100.0%) Total
=== AFTER THE PATCH ===
===-------------------------------------------------------------------------===
... Pass execution timing report ...
===-------------------------------------------------------------------------===
Total Execution Time: 0.5338 seconds (0.5355 wall clock)
---User Time--- --System Time-- --User+System-- ---Wall Time--- --- Name ---
0.2498 ( 48.6%) 0.0118 ( 59.3%) 0.2615 ( 49.0%) 0.2629 ( 49.1%) Bitcode Writer
0.1377 ( 26.8%) 0.0075 ( 37.8%) 0.1452 ( 27.2%) 0.1455 ( 27.2%) Called Value Propagation
0.1264 ( 24.6%) 0.0006 ( 3.0%) 0.1270 ( 23.8%) 0.1271 ( 23.7%) Module Verifier
0.5139 (100.0%) 0.0199 (100.0%) 0.5338 (100.0%) 0.5355 (100.0%) Total
Reviewers: davide, mssimpso
Reviewed By: davide
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D49108
llvm-svn: 342398