Revert "[Metadata] Preserve MD_prof when merging instructions when one is missing."

[snehasish]

Reverts #132433

I suspect this change caused a failure in the bolt build bot.
https://lab.llvm.org/buildbot/#/builders/113/builds/6621

!9185 = !{!"branch_weights", i32 3912, i32 802}
Wrong number of operands
!9185 = !{!"branch_weights", i32 3912, i32 802}
fatal error: error in backend: Broken module found, compilation aborted!

[llvmbot]

@llvm/pr-subscribers-llvm-transforms

Author: Snehasish Kumar (snehasish)

Changes

Reverts llvm/llvm-project#132433

I suspect this change caused a failure in the bolt build bot.
https://lab.llvm.org/buildbot/#/builders/113/builds/6621

!9185 = !{!"branch_weights", i32 3912, i32 802}
Wrong number of operands
!9185 = !{!"branch_weights", i32 3912, i32 802}
fatal error: error in backend: Broken module found, compilation aborted!

---

Full diff: https://github.com/llvm/llvm-project/pull/134200.diff

3 Files Affected:

• (modified) llvm/lib/Transforms/Utils/Local.cpp (+6-13)
• (removed) llvm/test/Transforms/SimplifyCFG/merge-direct-call-branch-weights-preserve-hoist.ll (-62)
• (removed) llvm/test/Transforms/SimplifyCFG/merge-direct-call-branch-weights-preserve-sink.ll (-63)

diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index c136825d47b9c..edec0e7a94422 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -3355,10 +3355,9 @@ static void combineMetadata(Instruction *K, const Instruction *J,
       case LLVMContext::MD_invariant_group:
         // Preserve !invariant.group in K.
         break;
-      // Keep empty cases for prof, mmra, memprof, and callsite to prevent them
-      // from being removed as unknown metadata. The actual merging is handled
+      // Keep empty cases for mmra, memprof, and callsite to prevent them from
+      // being removed as unknown metadata. The actual merging is handled
       // separately below.
-      case LLVMContext::MD_prof:
       case LLVMContext::MD_mmra:
       case LLVMContext::MD_memprof:
       case LLVMContext::MD_callsite:
@@ -3387,6 +3386,10 @@ static void combineMetadata(Instruction *K, const Instruction *J,
         if (!AAOnly)
           K->setMetadata(Kind, JMD);
         break;
+      case LLVMContext::MD_prof:
+        if (!AAOnly && DoesKMove)
+          K->setMetadata(Kind, MDNode::getMergedProfMetadata(KMD, JMD, K, J));
+        break;
       case LLVMContext::MD_noalias_addrspace:
         if (DoesKMove)
           K->setMetadata(Kind,
@@ -3433,16 +3436,6 @@ static void combineMetadata(Instruction *K, const Instruction *J,
     K->setMetadata(LLVMContext::MD_callsite,
                    MDNode::getMergedCallsiteMetadata(KCallSite, JCallSite));
   }
-
-  // Merge prof metadata.
-  // Handle separately to support cases where only one instruction has the
-  // metadata.
-  auto *JProf = J->getMetadata(LLVMContext::MD_prof);
-  auto *KProf = K->getMetadata(LLVMContext::MD_prof);
-  if (!AAOnly && (JProf || KProf)) {
-    K->setMetadata(LLVMContext::MD_prof,
-                   MDNode::getMergedProfMetadata(KProf, JProf, K, J));
-  }
 }
 
 void llvm::combineMetadataForCSE(Instruction *K, const Instruction *J,
diff --git a/llvm/test/Transforms/SimplifyCFG/merge-direct-call-branch-weights-preserve-hoist.ll b/llvm/test/Transforms/SimplifyCFG/merge-direct-call-branch-weights-preserve-hoist.ll
deleted file mode 100644
index d6058134f5285..0000000000000
--- a/llvm/test/Transforms/SimplifyCFG/merge-direct-call-branch-weights-preserve-hoist.ll
+++ /dev/null
@@ -1,62 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals --version 2
-; RUN: opt < %s -passes='simplifycfg<no-sink-common-insts;hoist-common-insts>' -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s --check-prefix=HOIST
-
-; Test case based on C++ code with manualy annotated !prof metadata.
-; This is to test that when calls to 'func1' from 'if.then' block
-; and 'if.else' block are hoisted, the branch_weights are merged and
-; attached to merged call rather than dropped.
-;
-; int func1(int a, int b) ;
-; int func2(int a, int b) ;
-
-; int func(int a, int b, bool c) {
-;    int sum= 0;
-;    if(c) {
-;        sum += func1(a, b);
-;    } else {
-;        sum += func1(a, b);
-;        sum -= func2(a, b);
-;    }
-;    return sum;
-; }
-define i32 @_Z4funciib(i32 %a, i32 %b, i1 %c) {
-; HOIST-LABEL: define i32 @_Z4funciib
-; HOIST-SAME: (i32 [[A:%.*]], i32 [[B:%.*]], i1 [[C:%.*]]) {
-; HOIST-NEXT:  entry:
-; HOIST-NEXT:    [[CALL:%.*]] = tail call i32 @_Z5func1ii(i32 [[A]], i32 [[B]]), !prof [[PROF0:![0-9]+]]
-; HOIST-NEXT:    br i1 [[C]], label [[IF_END:%.*]], label [[IF_ELSE:%.*]]
-; HOIST:       if.else:
-; HOIST-NEXT:    [[CALL3:%.*]] = tail call i32 @_Z5func2ii(i32 [[A]], i32 [[B]])
-; HOIST-NEXT:    [[SUB:%.*]] = sub i32 [[CALL]], [[CALL3]]
-; HOIST-NEXT:    br label [[IF_END]]
-; HOIST:       if.end:
-; HOIST-NEXT:    [[SUM_0:%.*]] = phi i32 [ [[SUB]], [[IF_ELSE]] ], [ [[CALL]], [[ENTRY:%.*]] ]
-; HOIST-NEXT:    ret i32 [[SUM_0]]
-;
-entry:
-  br i1 %c, label %if.then, label %if.else
-
-if.then:                                          ; preds = %entry
-  %call = tail call i32 @_Z5func1ii(i32 %a, i32 %b)
-  br label %if.end
-
-if.else:                                          ; preds = %entry
-  %call1 = tail call i32 @_Z5func1ii(i32 %a, i32 %b), !prof !0
-  %call3 = tail call i32 @_Z5func2ii(i32 %a, i32 %b)
-  %sub = sub i32 %call1, %call3
-  br label %if.end
-
-if.end:                                           ; preds = %if.else, %if.then
-  %sum.0 = phi i32 [ %call, %if.then ], [ %sub, %if.else ]
-  ret i32 %sum.0
-}
-
-declare i32 @_Z5func1ii(i32, i32)
-
-declare i32 @_Z5func2ii(i32, i32)
-
-!0 = !{!"branch_weights", i32 10}
-
-;.
-; HOIST: [[PROF0]] = !{!"branch_weights", i32 10}
-;.
diff --git a/llvm/test/Transforms/SimplifyCFG/merge-direct-call-branch-weights-preserve-sink.ll b/llvm/test/Transforms/SimplifyCFG/merge-direct-call-branch-weights-preserve-sink.ll
deleted file mode 100644
index c4aed5eb95888..0000000000000
--- a/llvm/test/Transforms/SimplifyCFG/merge-direct-call-branch-weights-preserve-sink.ll
+++ /dev/null
@@ -1,63 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals --version 2
-; RUN: opt < %s -passes='simplifycfg<sink-common-insts;no-hoist-common-insts>' -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s --check-prefix=SINK
-
-
-; Test case based on the following C++ code with manualy annotated !prof metadata.
-; This is to test that when calls to 'func1' from 'if.then' and 'if.else' are
-; sinked, the branch weights are merged and attached to sinked call.
-;
-; int func1(int a, int b) ;
-; int func2(int a, int b) ;
-
-; int func(int a, int b, bool c) {
-;    int sum = 0;
-;    if (c) {
-;        sum += func1(a,b);
-;    } else {
-;        b -= func2(a,b);
-;        sum += func1(a,b);
-;    }
-;    return sum;
-; }
-
-define i32 @_Z4funciib(i32 %a, i32 %b, i1 %c) {
-; SINK-LABEL: define i32 @_Z4funciib
-; SINK-SAME: (i32 [[A:%.*]], i32 [[B:%.*]], i1 [[C:%.*]]) {
-; SINK-NEXT:  entry:
-; SINK-NEXT:    br i1 [[C]], label [[IF_END:%.*]], label [[IF_ELSE:%.*]]
-; SINK:       if.else:
-; SINK-NEXT:    [[CALL1:%.*]] = tail call i32 @_Z5func2ii(i32 [[A]], i32 [[B]])
-; SINK-NEXT:    [[SUB:%.*]] = sub i32 [[B]], [[CALL1]]
-; SINK-NEXT:    br label [[IF_END]]
-; SINK:       if.end:
-; SINK-NEXT:    [[SUB_SINK:%.*]] = phi i32 [ [[SUB]], [[IF_ELSE]] ], [ [[B]], [[ENTRY:%.*]] ]
-; SINK-NEXT:    [[CALL2:%.*]] = tail call i32 @_Z5func1ii(i32 [[A]], i32 [[SUB_SINK]]), !prof [[PROF0:![0-9]+]]
-; SINK-NEXT:    ret i32 [[CALL2]]
-;
-entry:
-  br i1 %c, label %if.then, label %if.else
-
-if.then:                                          ; preds = %entry
-  %call = tail call i32 @_Z5func1ii(i32 %a, i32 %b), !prof !0
-  br label %if.end
-
-if.else:                                          ; preds = %entry
-  %call1 = tail call i32 @_Z5func2ii(i32 %a, i32 %b)
-  %sub = sub i32 %b, %call1
-  %call2 = tail call i32 @_Z5func1ii(i32 %a, i32 %sub)
-  br label %if.end
-
-if.end:                                           ; preds = %if.else, %if.then
-  %sum.0 = phi i32 [ %call, %if.then ], [ %call2, %if.else ]
-  ret i32 %sum.0
-}
-
-declare i32 @_Z5func1ii(i32, i32)
-
-declare i32 @_Z5func2ii(i32, i32)
-
-!0 = !{!"branch_weights", i32 10}
-
-;.
-; SINK: [[PROF0]] = !{!"branch_weights", i32 10}
-;.