Fix PR4926. When target hook EmitInstrWithCustomInserter() insert new basic blocks and update CFG, it should also inform sdisel of the changes so the phi source operands will come from the right basic blocks.

llvm-svn: 82311

1 files changed, 18 insertions, 15 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 2b2de9a7e03..b99739d13bb 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -7675,16 +7675,10 @@ X86TargetLowering::EmitPCMP(MachineInstr *MI, MachineBasicBlock *BB,
   const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
 
   unsigned Opc;
-
-  if (memArg) {
-    Opc = numArgs == 3 ?
-      X86::PCMPISTRM128rm :
-      X86::PCMPESTRM128rm;
-  } else {
-    Opc = numArgs == 3 ?
-      X86::PCMPISTRM128rr :
-      X86::PCMPESTRM128rr;
-  }
+  if (memArg)
+    Opc = numArgs == 3 ? X86::PCMPISTRM128rm : X86::PCMPESTRM128rm;
+  else
+    Opc = numArgs == 3 ? X86::PCMPISTRM128rr : X86::PCMPESTRM128rr;
 
   MachineInstrBuilder MIB = BuildMI(BB, dl, TII->get(Opc));
 
@@ -7773,7 +7767,8 @@ X86TargetLowering::EmitVAStartSaveXMMRegsWithCustomInserter(
 
 MachineBasicBlock *
 X86TargetLowering::EmitLoweredSelect(MachineInstr *MI,
-                                     MachineBasicBlock *BB) const {
+                                     MachineBasicBlock *BB,
+                   DenseMap<MachineBasicBlock*, MachineBasicBlock*> *EM) const {
   const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
   DebugLoc DL = MI->getDebugLoc();
   
@@ -7800,10 +7795,18 @@ X86TargetLowering::EmitLoweredSelect(MachineInstr *MI,
   BuildMI(BB, DL, TII->get(Opc)).addMBB(sinkMBB);
   F->insert(It, copy0MBB);
   F->insert(It, sinkMBB);
-  // Update machine-CFG edges by transferring all successors of the current
+  // Update machine-CFG edges by first adding all successors of the current
   // block to the new block which will contain the Phi node for the select.
-  sinkMBB->transferSuccessors(BB);
-  
+  // Also inform sdisel of the edge changes.
+  for (MachineBasicBlock::succ_iterator I = BB->succ_begin(), 
+         E = BB->succ_end(); I != E; ++I) {
+    EM->insert(std::make_pair(*I, sinkMBB));
+    sinkMBB->addSuccessor(*I);
+  }
+  // Next, remove all successors of the current block, and add the true
+  // and fallthrough blocks as its successors.
+  while (!BB->succ_empty())
+    BB->removeSuccessor(BB->succ_begin());
   // Add the true and fallthrough blocks as its successors.
   BB->addSuccessor(copy0MBB);
   BB->addSuccessor(sinkMBB);
@@ -7842,7 +7845,7 @@ X86TargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
   case X86::CMOV_V4F32:
   case X86::CMOV_V2F64:
   case X86::CMOV_V2I64:
-    return EmitLoweredSelect(MI, BB);
+    return EmitLoweredSelect(MI, BB, EM);
 
   case X86::FP32_TO_INT16_IN_MEM:
   case X86::FP32_TO_INT32_IN_MEM: