aaron.ballman accepted this revision.
aaron.ballman added a comment.
This revision is now accepted and ready to land.
LGTM
================
Comment at: clang/lib/Sema/SemaType.cpp:8338
// The attribute vector size must match -mrvv-vector-bits.
- if (VecSize != VScale->first * MinElts * EltSize) {
+ unsigned ExpectedSize = VScale->first * MinElts * EltSize;
+ if (VecSize != ExpectedSize) {
----------------
craig.topper wrote:
> aaron.ballman wrote:
> > Random thought I didn't think to ask earlier: is it possible for this
> > multiplication to overflow (if so, we should add test coverage to make sure
> > we don't do bad things)?
> The largest value for -mrvv-vector-bits is 65536 which makes VScale->first
> 65536/64 == 1024. MinElts and EltSize should be small enough that it won't
> overflow.
>
> I'm not sure if there's any protection if someone bypasses the driver with
> `-Xclang -mvscale-min=` and uses a larger value.
> The largest value for -mrvv-vector-bits is 65536 which makes VScale->first
> 65536/64 == 1024. MinElts and EltSize should be small enough that it won't
> overflow.
Fantastic, thank you!
> I'm not sure if there's any protection if someone bypasses the driver with
> -Xclang -mvscale-min= and uses a larger value.
IMO, using cc1 options is compiler YOLO-mode, so I don't mind if this has no
protection.
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D150926/new/
https://reviews.llvm.org/D150926
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