Fix X86FastISel's address-mode folding to stay within the

original basic block. This avoids trouble with examining
instructions in other basic blocks which haven't been
assigned registers yet.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106310 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index 7bbe6ab5751703557287c6605792f42e8c2c8e02..cbdfd648429009f42675fa72e80f8a0ff6936efb 100644 (file)
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -342,6 +342,12 @@ bool X86FastISel::X86SelectAddress(const Value *V, X86AddressMode &AM) {
   const User *U = NULL;
   unsigned Opcode = Instruction::UserOp1;
   if (const Instruction *I = dyn_cast<Instruction>(V)) {
+    // Don't walk into other basic blocks; it's possible we haven't
+    // visited them yet, so the instructions may not yet be assigned
+    // virtual registers.
+    if (MBBMap[I->getParent()] != MBB)
+      return false;
+
     Opcode = I->getOpcode();
     U = I;
   } else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(V)) {