[X86][FastISel] During X86 fastisel, the address of indirect call was resolved

through bitcast, ptrtoint, and inttoptr instructions. This is valid
only if the related instructions are in that same basic block, otherwise
we may reference variables that were not live accross basic blocks
resulting in undefined virtual registers.

The bug was exposed when both SDISel and FastISel were used within the same
function, i.e., one basic block is issued with FastISel and another with SDISel,
as demonstrated with the testcase.

<rdar://problem/15192473>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192636 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 7 deletions

diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index f048038..6bbc984 100644
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -632,9 +632,12 @@ redo_gep:
 bool X86FastISel::X86SelectCallAddress(const Value *V, X86AddressMode &AM) {
   const User *U = NULL;
   unsigned Opcode = Instruction::UserOp1;
-  if (const Instruction *I = dyn_cast<Instruction>(V)) {
+  const Instruction *I = dyn_cast<Instruction>(V);
+  bool InMBB = true;
+  if (I) {
     Opcode = I->getOpcode();
     U = I;
+    InMBB = I->getParent() == FuncInfo.MBB->getBasicBlock();
   } else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(V)) {
     Opcode = C->getOpcode();
     U = C;
@@ -643,18 +646,22 @@ bool X86FastISel::X86SelectCallAddress(const Value *V, X86AddressMode &AM) {
   switch (Opcode) {
   default: break;
   case Instruction::BitCast:
-    // Look past bitcasts.
-    return X86SelectCallAddress(U->getOperand(0), AM);
+    // Look past bitcasts if its operand is in the same BB.
+    if (InMBB)
+      return X86SelectCallAddress(U->getOperand(0), AM);
+    break;
 
   case Instruction::IntToPtr:
-    // Look past no-op inttoptrs.
-    if (TLI.getValueType(U->getOperand(0)->getType()) == TLI.getPointerTy())
+    // Look past no-op inttoptrs if its operand is in the same BB.
+    if (InMBB &&
+        TLI.getValueType(U->getOperand(0)->getType()) == TLI.getPointerTy())
       return X86SelectCallAddress(U->getOperand(0), AM);
     break;
 
   case Instruction::PtrToInt:
-    // Look past no-op ptrtoints.
-    if (TLI.getValueType(U->getType()) == TLI.getPointerTy())
+    // Look past no-op ptrtoints if its operand is in the same BB.
+    if (InMBB &&
+        TLI.getValueType(U->getType()) == TLI.getPointerTy())
       return X86SelectCallAddress(U->getOperand(0), AM);
     break;
   }