[PATCH] D127729: [Bitcode] Support expanding constant expressions into instructions

[Benjamin Kramer via Phabricator via llvm-commits]

bkramer added inline comments.


================
Comment at: llvm/lib/Bitcode/Reader/BitcodeReader.cpp:2822
-        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy, OpTyID);
-        V = UpgradeBitCastExpr(Opc, Op, CurTy);
-        if (!V) V = ConstantExpr::getCast(Opc, Op, CurTy);
----------------
I found a 2013 vintage CUDA bitcode file that relies on this upgrader. It does
```
@unrollpragma = private addrspace(1) constant [17 x i8] c"#pragma unroll 1\00"
bitcast @unrollpragma to i8*
```

Bitcasting away addrspace has been disallowed since the advent of addrspacecast. Was this backwards compat dropped accidentally or is it time to drop this upgrader?

If we want the latter we can also remove it from AutoUpgrade.cpp.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D127729/new/

https://reviews.llvm.org/D127729