[WinEH] Update PHIs of CATCHRET successors

The TailDuplication machine pass ran across a malformed CFG: a PHI node
referred it's predecessor's predecessor instead of it's predecessor.
This occurred because we split the edge in X86ISelLowering when we
processed the CATCHRET but forgot to do something about the PHI nodes.

This fixes PR25444.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252413 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index f5efd58e7a384ce0856be6a27c2e1cbd72dc801c..8d7712d3cd07a4de22e5ceba0e14417afdc838af 100644 (file)
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -21419,10 +21419,10 @@ X86TargetLowering::EmitLoweredCatchRet(MachineInstr *MI,
   // the new block to the return destination with a normal JMP_4.
   MachineBasicBlock *RestoreMBB =
       MF->CreateMachineBasicBlock(BB->getBasicBlock());
+  assert(BB->succ_size() == 1);
   MF->insert(TargetMBB->getIterator(), RestoreMBB);
-  BB->removeSuccessor(TargetMBB);
+  RestoreMBB->transferSuccessorsAndUpdatePHIs(BB);
   BB->addSuccessor(RestoreMBB);
-  RestoreMBB->addSuccessor(TargetMBB);
   MI->getOperand(0).setMBB(RestoreMBB);
 
   auto RestoreMBBI = RestoreMBB->begin();

diff --git a/test/CodeGen/X86/tail-dup-catchret.ll b/test/CodeGen/X86/tail-dup-catchret.ll
new file mode 100644 (file)
index 0000000..18682fb
--- /dev/null
+++ b/test/CodeGen/X86/tail-dup-catchret.ll
@@ -0,0 +1,34 @@
+; RUN: llc < %s | FileCheck %s
+target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
+target triple = "i686-pc-windows-msvc18.0.0"
+
+define void @f() personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*) {
+entry:
+  invoke void @g()
+          to label %try.cont unwind label %catch.dispatch
+
+catch.dispatch:                                   ; preds = %entry
+  %0 = catchpad [i8* null, i32 64, i8* null]
+          to label %catch unwind label %catchendblock
+
+catch:                                            ; preds = %catch.dispatch
+  catchret %0 to label %try.cont
+
+try.cont:                                         ; preds = %entry, %catch
+  %b.0 = phi i1 [ false, %catch ], [ true, %entry ]
+  tail call void @h(i1 zeroext %b.0)
+  ret void
+
+catchendblock:                                    ; preds = %catch.dispatch
+  catchendpad unwind to caller
+}
+
+; CHECK-LABEL: _f:
+; CHECK: calll _g
+; CHECK: calll _h
+
+declare void @g()
+
+declare i32 @__CxxFrameHandler3(...)
+
+declare void @h(i1 zeroext)