[Bitcode] Restore bitcast expression auto-upgrade

Restore the autoupgrade from bitcast to ptrtoint+inttoptr, which
was lost as part of D127729.

This fixes the backwards compatibility issue noted in:
https://reviews.llvm.org/D127729#inline-1236519

diff --git a/llvm/include/llvm/IR/AutoUpgrade.h b/llvm/include/llvm/IR/AutoUpgrade.h
index 96d20a7..12952f2 100644 (file)
--- a/llvm/include/llvm/IR/AutoUpgrade.h
+++ b/llvm/include/llvm/IR/AutoUpgrade.h
@@ -82,7 +82,7 @@ namespace llvm {
   /// This is an auto-upgrade for bitcast constant expression between pointers
   /// with different address spaces: the instruction is replaced by a pair
   /// ptrtoint+inttoptr.
-  Value *UpgradeBitCastExpr(unsigned Opc, Constant *C, Type *DestTy);
+  Constant *UpgradeBitCastExpr(unsigned Opc, Constant *C, Type *DestTy);
 
   /// Check the debug info version number, if it is out-dated, drop the debug
   /// info. Return true if module is modified.

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 7abe7c0..5e5ca96 100644 (file)
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1442,7 +1442,9 @@ Expected<Value *> BitcodeReader::materializeValue(unsigned StartValID,
     if (isConstExprSupported(BC->Opcode) && ConstOps.size() == Ops.size()) {
       Constant *C;
       if (Instruction::isCast(BC->Opcode)) {
-        C = ConstantExpr::getCast(BC->Opcode, ConstOps[0], BC->getType());
+        C = UpgradeBitCastExpr(BC->Opcode, ConstOps[0], BC->getType());
+        if (!C)
+          C = ConstantExpr::getCast(BC->Opcode, ConstOps[0], BC->getType());
       } else if (Instruction::isUnaryOp(BC->Opcode)) {
         C = ConstantExpr::get(BC->Opcode, ConstOps[0], BC->Flags);
       } else if (Instruction::isBinaryOp(BC->Opcode)) {

diff --git a/llvm/lib/IR/AutoUpgrade.cpp b/llvm/lib/IR/AutoUpgrade.cpp
index 2a4c315..75594f9 100644 (file)
--- a/llvm/lib/IR/AutoUpgrade.cpp
+++ b/llvm/lib/IR/AutoUpgrade.cpp
@@ -4179,7 +4179,7 @@ Instruction *llvm::UpgradeBitCastInst(unsigned Opc, Value *V, Type *DestTy,
   return nullptr;
 }
 
-Value *llvm::UpgradeBitCastExpr(unsigned Opc, Constant *C, Type *DestTy) {
+Constant *llvm::UpgradeBitCastExpr(unsigned Opc, Constant *C, Type *DestTy) {
   if (Opc != Instruction::BitCast)
     return nullptr;