[PATCH] D106209: [AbstractAttributor] Fix two issues in folding __kmpc_is_spmd_exec_mode

[Shilei Tian via Phabricator via llvm-commits]

tianshilei1992 created this revision.
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tianshilei1992 requested review of this revision.
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This patch fixed two issues found when folding `__kmpc_is_spmd_exec_mode`:

1. When the reaching kernels are empty, it should not fold to generic mode.
2. When creating AA for the caller when updating information, the dependency should be required.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D106209

Files:
  llvm/lib/Transforms/IPO/OpenMPOpt.cpp


Index: llvm/lib/Transforms/IPO/OpenMPOpt.cpp
===================================================================
--- llvm/lib/Transforms/IPO/OpenMPOpt.cpp
+++ llvm/lib/Transforms/IPO/OpenMPOpt.cpp
@@ -3196,8 +3196,8 @@
 
       assert(Caller && "Caller is nullptr");
 
-      auto &CAA =
-          A.getOrCreateAAFor<AAKernelInfo>(IRPosition::function(*Caller));
+      auto &CAA = A.getOrCreateAAFor<AAKernelInfo>(
+          IRPosition::function(*Caller), this, DepClassTy::REQUIRED);
       if (CAA.ReachingKernelEntries.isValidState()) {
         ReachingKernelEntries ^= CAA.ReachingKernelEntries;
         return true;
@@ -3521,12 +3521,16 @@
       // All reaching kernels are in SPMD mode. Update all function calls to
       // __kmpc_is_spmd_exec_mode to 1.
       SimplifiedValue = ConstantInt::get(Type::getInt8Ty(Ctx), true);
-    } else {
+    } else if (KnownNonSPMDCount || AssumedNonSPMDCount) {
       assert(KnownSPMDCount == 0 && AssumedSPMDCount == 0 &&
              "Expected only non-SPMD kernels!");
       // All reaching kernels are in non-SPMD mode. Update all function
       // calls to __kmpc_is_spmd_exec_mode to 0.
       SimplifiedValue = ConstantInt::get(Type::getInt8Ty(Ctx), false);
+    } else {
+      // We have empty reaching kernels, therefore we cannot tell if the
+      // associated call site can be folded.
+      SimplifiedValue = nullptr;
     }
 
     return SimplifiedValue == SimplifiedValueBefore ? ChangeStatus::UNCHANGED


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