[llvm] 4423a7a - [NewPM] Disable RelLookupTableConverter pass in LTO

[Gulfem Savrun Yeniceri via llvm-commits]

Author: Gulfem Savrun Yeniceri
Date: 2021-04-30T21:23:40Z
New Revision: 4423a7a09b1b0dc8558e06e1f84f144b28466d9b

URL: https://github.com/llvm/llvm-project/commit/4423a7a09b1b0dc8558e06e1f84f144b28466d9b
DIFF: https://github.com/llvm/llvm-project/commit/4423a7a09b1b0dc8558e06e1f84f144b28466d9b.diff

LOG: [NewPM] Disable RelLookupTableConverter pass in LTO

Relative look table converter pass caused an issue when full lto
is enabled (reported in https://reviews.llvm.org/D94355).
This patch disables that pass from full lto pre-link phase optimization
pipeline until the issue is fixed.

Differential Revision: https://reviews.llvm.org/D101664

Added: 
    

Modified: 
    llvm/lib/Passes/PassBuilder.cpp
    llvm/test/Other/new-pm-defaults.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index 31e9e14a25e9..8a694cd63a7e 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -1425,7 +1425,11 @@ PassBuilder::buildModuleOptimizationPipeline(OptimizationLevel Level,
   MPM.addPass(GlobalDCEPass());
   MPM.addPass(ConstantMergePass());
 
-  MPM.addPass(RelLookupTableConverterPass());
+  // TODO: Relative look table converter pass caused an issue when full lto is
+  // enabled. See https://reviews.llvm.org/D94355 for more details.
+  // Until the issue fixed, disable this pass during pre-linking phase.
+  if (!LTOPreLink)
+    MPM.addPass(RelLookupTableConverterPass());
 
   return MPM;
 }

diff  --git a/llvm/test/Other/new-pm-defaults.ll b/llvm/test/Other/new-pm-defaults.ll
index c934bb9978aa..7e7f2653b98b 100644
--- a/llvm/test/Other/new-pm-defaults.ll
+++ b/llvm/test/Other/new-pm-defaults.ll
@@ -260,8 +260,10 @@
 ; CHECK-O-NEXT: Running pass: CGProfilePass
 ; CHECK-O-NEXT: Running pass: GlobalDCEPass
 ; CHECK-O-NEXT: Running pass: ConstantMergePass
-; CHECK-O-NEXT: Running pass: RelLookupTableConverterPass
-; CHECK-O-NEXT: Running analysis: TargetIRAnalysis
+; CHECK-DEFAULT-NEXT: Running pass: RelLookupTableConverterPass
+; CHECK-LTO-NOT: Running pass: RelLookupTableConverterPass
+; CHECK-DEFAULT-NEXT: Running analysis: TargetIRAnalysis
+; CHECK-LTO-NOT: Running analysis: TargetIRAnalysis
 ; CHECK-O-NEXT: Running pass: AnnotationRemarksPass on foo
 ; CHECK-LTO-NEXT: Running pass: CanonicalizeAliasesPass
 ; CHECK-LTO-NEXT: Running pass: NameAnonGlobalPass