[ControlHeightReduction] Drop lifetime annotations where necessary

llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp

@@ -1592,6 +1592,12 @@ static void insertTrivialPHIs(CHRScope *Scope,
         TrivialPHIs.insert(PN);
         CHR_DEBUG(dbgs() << "Insert phi " << *PN << "\n");
         for (Instruction *UI : Users) {
+          // Drop lifetime annotations as it is illegal for them to refer to a
+          // phi node.
+          if (UI->isLifetimeStartOrEnd()) {
+            UI->eraseFromParent();
+            continue;
+          }
           for (unsigned J = 0, NumOps = UI->getNumOperands(); J < NumOps; ++J) {
             if (UI->getOperand(J) == &I) {
               UI->setOperand(J, PN);

llvm/test/Transforms/PGOProfile/chr.ll

@@ -2678,6 +2678,65 @@ bb6:
   ret void
 }
 
+; Test that when we create phi nodes for allocas, we drop lifetime annotations
+; that would otherwise be illegally referring to a phi node.
+declare void @baz(i64)
+declare void @llvm.lifetime.start.p0(ptr captures(none))
+define void @test_chr_with_lifetimes(ptr %i) !prof !14 {
+; CHECK-LABEL: @test_chr_with_lifetimes(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, ptr [[I:%.*]], align 4
+; CHECK-NEXT:    [[DOTFR:%.*]] = freeze i32 [[TMP0]]
+; CHECK-NEXT:    [[DOTNOT:%.*]] = icmp eq i32 [[DOTFR]], 0
+; CHECK-NEXT:    br i1 [[DOTNOT]], label [[ENTRY_SPLIT_NONCHR:%.*]], label [[ENTRY_SPLIT:%.*]], !prof [[PROF21:![0-9]+]]
+; CHECK:       entry.split:
+; CHECK-NEXT:    [[TEST:%.*]] = alloca i32, align 8
+; CHECK-NEXT:    call void @baz(i64 0)
+; CHECK-NEXT:    call void @foo()
+; CHECK-NEXT:    br label [[BB1:%.*]]
+; CHECK:       entry.split.nonchr:
+; CHECK-NEXT:    [[TEST_NONCHR:%.*]] = alloca i32, align 8
+; CHECK-NEXT:    call void @baz(i64 4)
+; CHECK-NEXT:    br label [[BB1]]
+; CHECK:       bb1:
+; CHECK-NEXT:    [[TMP1:%.*]] = phi ptr [ [[TEST]], [[ENTRY_SPLIT]] ], [ [[TEST_NONCHR]], [[ENTRY_SPLIT_NONCHR]] ]
+; CHECK-NEXT:    store ptr [[TMP1]], ptr [[I]], align 8
+; CHECK-NEXT:    br label [[BB2:%.*]]
+; CHECK:       bb2:
+; CHECK-NEXT:    [[TMP2:%.*]] = phi ptr [ [[TMP3:%.*]], [[BB2]] ], [ null, [[BB1]] ]
+; CHECK-NEXT:    [[TMP3]] = getelementptr i8, ptr [[TMP2]], i64 24
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp eq ptr [[TMP2]], [[I]]
+; CHECK-NEXT:    br i1 [[TMP4]], label [[BB3:%.*]], label [[BB2]]
+; CHECK:       bb3:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %1 = load i32, ptr %i
+  %2 = icmp eq i32 %1, 0
+  %3 = select i1 %2, i64 4, i64 0, !prof !15
+  %test = alloca i32, align 8
+  call void @baz(i64 %3)
+  br i1 %2, label %bb1, label %bb0, !prof !15
+
+bb0:
+  call void @foo()
+  br label %bb1
+
+bb1:
+  call void @llvm.lifetime.start.p0(ptr %test)
+  store ptr %test, ptr %i, align 8
+  br label %bb2
+
+bb2:
+  %4 = phi ptr [ %5, %bb2 ], [ null, %bb1 ]
+  %5 = getelementptr i8, ptr %4, i64 24
+  %6 = icmp eq ptr %4, %i
+  br i1 %6, label %bb3, label %bb2
+
+bb3:
+  ret void
+}
+
 
 !llvm.module.flags = !{!0}
 !0 = !{i32 1, !"ProfileSummary", !1}