diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Transforms/IPO/PassManagerBuilder.cpp | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp index bfc6bbdb816..1913b50405b 100644 --- a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp +++ b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp @@ -830,8 +830,22 @@ void PassManagerBuilder::populateThinLTOPassManager( if (VerifyInput) PM.add(createVerifierPass()); - if (Summary) + if (Summary) { + // These passes import type identifier resolutions for whole-program + // devirtualization and CFI. They must run early because other passes may + // disturb the specific instruction patterns that these passes look for, + // creating dependencies on resolutions that may not appear in the summary. + // + // For example, GVN may transform the pattern assume(type.test) appearing in + // two basic blocks into assume(phi(type.test, type.test)), which would + // transform a dependency on a WPD resolution into a dependency on a type + // identifier resolution for CFI. + // + // Also, WPD has access to more precise information than ICP and can + // devirtualize more effectively, so it should operate on the IR first. + PM.add(createWholeProgramDevirtPass(PassSummaryAction::Import, Summary)); PM.add(createLowerTypeTestsPass(PassSummaryAction::Import, Summary)); + } populateModulePassManager(PM); |
