[opaque pointer type] Bitcode support for explicit type parameter on GEP.

Like r230414, add bitcode support including backwards compatibility, for
an explicit type parameter to GEP.

At the suggestion of Duncan I tried coalescing the two older bitcodes into a
single new bitcode, though I did hit a wrinkle: I couldn't figure out how to
create an explicit abbreviation for a record with a variable number of
arguments (the indicies to the gep). This means the discriminator between
inbounds and non-inbounds gep is a full variable-length field I believe? Is my
understanding correct? Is there a way to create such an abbreviation? Should I
just use two bitcodes as before?

Reviewers: dexonsmith

Differential Revision: http://reviews.llvm.org/D7736

llvm-svn: 230415

1 files changed, 17 insertions, 3 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index c45e964..92af0f8 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -3062,9 +3062,22 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       InstructionList.push_back(I);
       break;
     }
-    case bitc::FUNC_CODE_INST_INBOUNDS_GEP:
-    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
+    case bitc::FUNC_CODE_INST_INBOUNDS_GEP_OLD:
+    case bitc::FUNC_CODE_INST_GEP_OLD:
+    case bitc::FUNC_CODE_INST_GEP: { // GEP: type, [n x operands]
       unsigned OpNum = 0;
+
+      Type *Ty;
+      bool InBounds;
+
+      if (BitCode == bitc::FUNC_CODE_INST_GEP) {
+        InBounds = Record[OpNum++];
+        Ty = getTypeByID(Record[OpNum++]);
+      } else {
+        InBounds = BitCode == bitc::FUNC_CODE_INST_INBOUNDS_GEP_OLD;
+        Ty = nullptr;
+      }
+
       Value *BasePtr;
       if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
         return Error("Invalid record");
@@ -3078,8 +3091,9 @@ std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
       }
 
       I = GetElementPtrInst::Create(BasePtr, GEPIdx);
+      assert(!Ty || Ty == cast<GetElementPtrInst>(I)->getSourceElementType());
       InstructionList.push_back(I);
-      if (BitCode == bitc::FUNC_CODE_INST_INBOUNDS_GEP)
+      if (InBounds)
         cast<GetElementPtrInst>(I)->setIsInBounds(true);
       break;
     }