PNaCl bitcode: Change FORWARDTYPEREF to never use pointer types

Before, FORWARDTYPEREFs used i8* type rather than i32 if they
referenced an "alloca" instruction.

Clean this up so that FORWARDTYPEREFs use i32 instead in this case.

Note that this means that a forward-referenced "alloca" can be used
via an ptrtoint+inttoptr, rather than a bitcast, but that's no
problem.

This is a step towards removing TYPE_CODE_POINTER from the types
table, to simplify the PNaCl bitcode format.

Rename NormalizeParamType() to NormalizeScalarType() to reflect that
it's used in more cases; make it public.

BUG=https://code.google.com/p/nativeclient/issues/detail?id=3671
TEST=test/NaCl/Bitcode/*.ll

Review URL: https://codereview.chromium.org/23719016

1 files changed, 10 insertions, 2 deletions

diff --git a/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp b/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
index 276d1d59b3..f5fd1ba0e7 100644
--- a/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
+++ b/lib/Bitcode/NaCl/Reader/NaClBitcodeReader.cpp
@@ -1579,8 +1579,16 @@ bool NaClBitcodeReader::ParseFunctionBody(Function *F) {
     }
 
     // Non-void values get registered in the value table for future use.
-    if (I && !I->getType()->isVoidTy())
-      ValueList.AssignValue(I, NextValueNo++);
+    if (I && !I->getType()->isVoidTy()) {
+      Value *NewVal = I;
+      if (GetPNaClVersion() >= 2 &&
+          NewVal->getType()->isPointerTy() &&
+          ValueList.getValueFwdRef(NextValueNo)) {
+        // Forward-referenced values cannot have pointer type.
+        NewVal = ConvertOpToScalar(NewVal, CurBBNo);
+      }
+      ValueList.AssignValue(NewVal, NextValueNo++);
+    }
   }
 
 OutOfRecordLoop: