Summary:
The ISA is really supposed to support 64-bit atomics as well,
so the data type should be an overload.
Mesa doesn't use these atomics yet, in fact I noticed this
issue while trying to use the atomics from Mesa.
Change-Id: I77f58317a085a0d3eb933cc7e99308c48a19f83e
Reviewers: tpr
Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, t-tye, jfb, llvm-commits
Differential Revision: https://reviews.llvm.org/D52291
llvm-svn: 343978
This commit adds a new IR level pass to the AMDGPU backend to perform
atomic optimizations. It works by:
- Running through a function and finding atomicrmw add/sub or uses of
the atomic buffer intrinsics for add/sub.
- If all arguments except the value to be added/subtracted are uniform,
record the value to be optimized.
- Run through the atomic operations we can optimize and, depending on
whether the value is uniform/divergent use wavefront wide operations
(DPP in the divergent case) to calculate the total amount to be
atomically added/subtracted.
- Then let only a single lane of each wavefront perform the atomic
operation, reducing the total number of atomic operations in flight.
- Lastly we recombine the result from the single lane to each lane of
the wavefront, and calculate our individual lanes offset into the
final result.
Differential Revision: https://reviews.llvm.org/D51969
llvm-svn: 343973
Summary:
This commit adds new intrinsics
llvm.amdgcn.raw.buffer.load
llvm.amdgcn.raw.buffer.load.format
llvm.amdgcn.raw.buffer.load.format.d16
llvm.amdgcn.struct.buffer.load
llvm.amdgcn.struct.buffer.load.format
llvm.amdgcn.struct.buffer.load.format.d16
llvm.amdgcn.raw.buffer.store
llvm.amdgcn.raw.buffer.store.format
llvm.amdgcn.raw.buffer.store.format.d16
llvm.amdgcn.struct.buffer.store
llvm.amdgcn.struct.buffer.store.format
llvm.amdgcn.struct.buffer.store.format.d16
llvm.amdgcn.raw.buffer.atomic.*
llvm.amdgcn.struct.buffer.atomic.*
with the following changes from the llvm.amdgcn.buffer.*
intrinsics:
* there are separate raw and struct versions: raw does not have an
index arg and sets idxen=0 in the instruction, and struct always sets
idxen=1 in the instruction even if the index is 0, to allow for the
fact that gfx9 does bounds checking differently depending on whether
idxen is set;
* there is a combined cachepolicy arg (glc+slc)
* there are now only two offset args: one for the offset that is
included in bounds checking and swizzling, to be split between the
instruction's voffset and immoffset fields, and one for the offset
that is excluded from bounds checking and swizzling, to go into the
instruction's soffset field.
The AMDISD::BUFFER_* SD nodes always have an index operand, all three
offset operands, combined cachepolicy operand, and an extra idxen
operand.
The obsolescent llvm.amdgcn.buffer.* intrinsics continue to work.
Subscribers: arsenm, kzhuravl, wdng, nhaehnle, yaxunl, dstuttard, t-tye, jfb, llvm-commits
Differential Revision: https://reviews.llvm.org/D50306
Change-Id: If897ea7dc34fcbf4d5496e98cc99a934f62fc205
llvm-svn: 340269
Nicolai Haehnle