[SimplifyCFG] Teach simplifyCommonResume() to preserve DomTree

diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index 0e7a8a7..ced2b68 100644 (file)
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -4159,7 +4159,7 @@ bool SimplifyCFGOpt::simplifyCommonResume(ResumeInst *RI) {
     for (pred_iterator PI = pred_begin(TrivialBB), PE = pred_end(TrivialBB);
          PI != PE;) {
       BasicBlock *Pred = *PI++;
-      removeUnwindEdge(Pred);
+      removeUnwindEdge(Pred, DTU);
       ++NumInvokes;
     }
 
@@ -4170,11 +4170,17 @@ bool SimplifyCFGOpt::simplifyCommonResume(ResumeInst *RI) {
     // predecessors.
     TrivialBB->getTerminator()->eraseFromParent();
     new UnreachableInst(RI->getContext(), TrivialBB);
+    if (DTU)
+      DTU->applyUpdatesPermissive({{DominatorTree::Delete, TrivialBB, BB}});
   }
 
   // Delete the resume block if all its predecessors have been removed.
-  if (pred_empty(BB))
-    BB->eraseFromParent();
+  if (pred_empty(BB)) {
+    if (DTU)
+      DTU->deleteBB(BB);
+    else
+      BB->eraseFromParent();
+  }
 
   return !TrivialUnwindBlocks.empty();
 }

diff --git a/llvm/test/Transforms/SimplifyCFG/X86/bug-25299.ll b/llvm/test/Transforms/SimplifyCFG/X86/bug-25299.ll
index 706afbe..294c593 100644 (file)
--- a/llvm/test/Transforms/SimplifyCFG/X86/bug-25299.ll
+++ b/llvm/test/Transforms/SimplifyCFG/X86/bug-25299.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -simplifycfg -S | FileCheck %s
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s
 
 ;; Test case for bug 25299, contributed by David Majnemer.
 

diff --git a/llvm/test/Transforms/SimplifyCFG/invoke_unwind_lifetime.ll b/llvm/test/Transforms/SimplifyCFG/invoke_unwind_lifetime.ll
index a498976..c758826 100644 (file)
--- a/llvm/test/Transforms/SimplifyCFG/invoke_unwind_lifetime.ll
+++ b/llvm/test/Transforms/SimplifyCFG/invoke_unwind_lifetime.ll
@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt < %s -simplifycfg -S | FileCheck %s
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s
 
 declare void @llvm.lifetime.start.p0i8(i64, i8*)
 declare void @llvm.lifetime.end.p0i8(i64, i8*)