[PATCH] D89980: [hip] Remove kernel argument coercion.

Matt Arsenault via Phabricator via cfe-commits cfe-commits at lists.llvm.org
Tue Oct 27 09:42:41 PDT 2020


arsenm added inline comments.


================
Comment at: clang/test/CodeGenCUDA/amdgpu-kernel-arg-pointer-type.cu:19
+// COMMON-LABEL: define amdgpu_kernel void @_Z7kernel1Pi(i32*{{.*}} %x)
+// OPT: [[VAL:%.*]] = load i32, i32* %x, align 4
 // OPT: [[INC:%.*]] = add nsw i32 [[VAL]], 1
----------------
hliao wrote:
> arsenm wrote:
> > hliao wrote:
> > > arsenm wrote:
> > > > This is still a regression. Fixing up AA does not solve the problem this promotions this is intended to solve. Generic accesses are worse independently of the aliasing properties
> > > Do you mean FLAT load/store has worse addressing mode than GLOBAL ones?
> > Yes. The flat offsets have a smaller range, and do not have the saddr mode. Flat accesses also won't avoid the extra lgmkcnt wait
> I plan to add support to select GLOBAL ones once we could confirm that pointer could only point to GLOBAL/CONSTANT address spaces. Do you think that's a reasonable solution?
I would much rather have the IR express the address space rather than fixing it up later. IR passes are aware of the addressing mode differences. Relying on AA for basic selection would also be worse for compile time


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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D89980/new/

https://reviews.llvm.org/D89980



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