[PATCH] D58982: DAG: allow DAG pointer size different from memory representation.

[Tim Northover via Phabricator via llvm-commits]

t.p.northover marked an inline comment as done.
t.p.northover added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp:4711
+
+  SDValue Val = DAG.getPtrExtOrTrunc(getValue(I.getValueOperand()), dl, MemVT);
+  SDValue OutChain = DAG.getAtomic(ISD::ATOMIC_STORE, dl, MemVT, InChain,
----------------
sanjoy wrote:
> This line crashes when we have an atomic store of a floating point number.  Simple reproducer:
> 
> ```
> target datalayout = "e-i64:64-i128:128-v16:16-v32:32-n16:32:64"
> target triple = "nvptx64-nvidia-cuda"
> 
> define void @f(float %a, float* %b) {
> entry:
>   store atomic float %a, float* %b unordered, align 4
>   ret void
> }
> ```
> 
> I think it needs to bitcast the value operand to an integer before truncating or extending it.
Sorry about that. I've put up a review to fix it in https://reviews.llvm.org/D61721 (the types are only different for pointers, so no need to add any extra casts).

I think it's pretty trivial, but just wanted to make sure I wasn't breaking some NVPTX testing rules or anything.


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D58982/new/

https://reviews.llvm.org/D58982