[PATCH] D82071: [IR] Convert profile metadata in createCallMatchingInvoke()

[Yevgeny Rouban via Phabricator via llvm-commits]

yrouban created this revision.
yrouban added reviewers: hans, bkramer, w2yehia, xur.
Herald added a subscriber: hiraditya.
Herald added a project: LLVM.

When an invoke instruction is converted to a call its profile metadata is dropped because it has incompatible format (see https://reviews.llvm.org/D81996).
This patch adds an attempt to convert profile data to format of the call instruction. This used to work well before the patch https://reviews.llvm.org/D80618.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D82071

Files:
  llvm/lib/Transforms/Utils/Local.cpp
  llvm/test/Transforms/SimplifyCFG/invoke_unwind.ll


Index: llvm/test/Transforms/SimplifyCFG/invoke_unwind.ll
===================================================================
--- llvm/test/Transforms/SimplifyCFG/invoke_unwind.ll
+++ llvm/test/Transforms/SimplifyCFG/invoke_unwind.ll
@@ -6,8 +6,7 @@
 ; instructions to call instructions if the handler just rethrows the exception.
 define i32 @test1() personality i32 (...)* @__gxx_personality_v0 {
 ; CHECK-LABEL: @test1(
-; CHECK-NEXT: call void @bar()
-; CHECK-NOT: !prof
+; CHECK-NEXT: call void @bar(), !prof ![[PROF:[0-9]+]]
 ; CHECK-NEXT: ret i32 0
         invoke void @bar( )
                         to label %1 unwind label %Rethrow, !prof !0
@@ -18,7 +17,7 @@
         resume { i8*, i32 } %exn
 }
 
-!0 = !{!"branch_weights", i32 369, i32 0}
+!0 = !{!"branch_weights", i32 369, i32 2}
 
 define i32 @test2() personality i32 (...)* @__gxx_personality_v0 {
 ; CHECK-LABEL: @test2(
@@ -76,3 +75,5 @@
 }
 
 declare i32 @__gxx_personality_v0(...)
+
+; CHECK: ![[PROF]] = !{!"branch_weights", i32 371}
Index: llvm/lib/Transforms/Utils/Local.cpp
===================================================================
--- llvm/lib/Transforms/Utils/Local.cpp
+++ llvm/lib/Transforms/Utils/Local.cpp
@@ -1986,9 +1986,16 @@
   NewCall->setDebugLoc(II->getDebugLoc());
   NewCall->copyMetadata(*II);
 
-  // If the invoke had profile metadata, drop it.
-  if (NewCall->hasMetadata(LLVMContext::MD_prof))
-    NewCall->setMetadata(LLVMContext::MD_prof, nullptr);
+  // If the invoke had profile metadata, try converting them for CallInst.
+  uint64_t TotalWeight;
+  if (NewCall->extractProfTotalWeight(TotalWeight)) {
+    // Set the total weight if it fits into i32, otherwise reset.
+    MDBuilder MDB(NewCall->getContext());
+    auto NewWeights = uint32_t(TotalWeight) != TotalWeight
+                          ? nullptr
+                          : MDB.createBranchWeights({uint32_t(TotalWeight)});
+    NewCall->setMetadata(LLVMContext::MD_prof, NewWeights);
+  }
 
   return NewCall;
 }


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