[llvm] d953d01 - Introduce -enable-global-analyses to allow users to disable inter-procedural analyses

[Nuno Lopes via llvm-commits]

Author: Nuno Lopes
Date: 2022-09-19T11:59:35+01:00
New Revision: d953d0173776e7f7109b35ac2e74259dd126ab74

URL: https://github.com/llvm/llvm-project/commit/d953d0173776e7f7109b35ac2e74259dd126ab74
DIFF: https://github.com/llvm/llvm-project/commit/d953d0173776e7f7109b35ac2e74259dd126ab74.diff

LOG: Introduce -enable-global-analyses to allow users to disable inter-procedural analyses

Alive2 doesn't support verification of optimizations that use inter-procedural analyses.
Right now, clang uses GlobalsAA by default and there's no way to disable it.
This leads to Alive2 producing false positives.
The added flag allows us to skip global analyses altogether.

Differential Revision: https://reviews.llvm.org/D134139

Added: 
    

Modified: 
    llvm/lib/Passes/PassBuilderPipelines.cpp

Removed: 
    


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diff  --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp
index 9255c011f965e..6d6b0749e9565 100644
--- a/llvm/lib/Passes/PassBuilderPipelines.cpp
+++ b/llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -186,6 +186,10 @@ static cl::opt<bool> EnablePostPGOLoopRotation(
     "enable-post-pgo-loop-rotation", cl::init(true), cl::Hidden,
     cl::desc("Run the loop rotation transformation after PGO instrumentation"));
 
+static cl::opt<bool> EnableGlobalAnalyses(
+    "enable-global-analyses", cl::init(true), cl::Hidden,
+    cl::desc("Enable inter-procedural analyses"));
+
 PipelineTuningOptions::PipelineTuningOptions() {
   LoopInterleaving = true;
   LoopVectorization = true;
@@ -1898,7 +1902,8 @@ AAManager PassBuilder::buildDefaultAAPipeline() {
   // Because the `AAManager` is a function analysis and `GlobalsAA` is a module
   // analysis, all that the `AAManager` can do is query for any *cached*
   // results from `GlobalsAA` through a readonly proxy.
-  AA.registerModuleAnalysis<GlobalsAA>();
+  if (EnableGlobalAnalyses)
+    AA.registerModuleAnalysis<GlobalsAA>();
 
   // Add target-specific alias analyses.
   if (TM)