[PATCH] D13826: [Bitcode] Limit bits used for CallingConv::ID in Function, update tests

[Reid Kleckner via llvm-commits]

rnk added a subscriber: rnk.
rnk added a comment.

Technically this is a bitcode backwards compatibility break, but I don't think anyone has ever used a calling convention ID greater than 1023 except in these test cases. I think we could get away with rejecting large calling convention IDs in the bitcode reader, though. After the reader, we can assert that truncation should not occur in setCallingConv for Function, InvokeInst, and CallInst.


================
Comment at: include/llvm/IR/Function.h:167
@@ -163,3 +166,3 @@
   void setCallingConv(CallingConv::ID CC) {
-    setValueSubclassData((getSubclassDataFromValue() & 7) |
-                         (static_cast<unsigned>(CC) << 3));
+    setValueSubclassData((getSubclassDataFromValue() & 0xc00f) |
+                         ((static_cast<unsigned>(CC) & 0x3ff) << 4));
----------------
Should this assert that CC < 1024?


http://reviews.llvm.org/D13826