In order to enable the LLVM frontend to better analyze buffer
operations (and to potentially enable more precise analyses on the
backend), define versions of the raw and structured buffer intrinsics
that use `ptr addrspace(8)` instead of `<4 x i32>` to represent their
rsrc arguments.
The new intrinsics are named by replacing `buffer.` with `buffer.ptr`.
One advantage to these intrinsic definitions is that, instead of
specifying that a buffer load/store will read/write some memory, we
can indicate that the memory read or written will be based on the
pointer argument. This means that, for example, a read from a
`noalias` buffer can be pulled out of a loop that is modifying a
distinct buffer.
In the future, we will define custom PseudoSourceValues that will
allow us to package up the (buffer, index, offset) triples that buffer
intrinsics contain and allow for more precise backend analysis.
This work also enables creating address space 7, which represents
manipulation of raw buffers using native LLVM load and store
instructions.
Where tests simply used a buffer intrinsic while testing some other
code path (such as the tests for VGPR spills), they have been updated
to use the new intrinsic form. Tests that are "about" buffer
intrinsics (for instance, those that ensure that they codegen as
expected) have been duplicated, either within existing files or into
new ones.
Depends on D145441
Reviewed By: arsenm, #amdgpu
Differential Revision: https://reviews.llvm.org/D147547
Edit the IR input for some codegen tests to simulate what the IR code
sinking pass would do to it. This makes the tests immune to the presence
or absence of the code sinking pass in the codegen pass pipeline, which
does not belong there.
Differential Revision: https://reviews.llvm.org/D130169
This patch merges a consecutive sequence of
s_or_saveexec s_o, s_i
s_xor exec, exec, s_o
into a single
s_andn2_saveexec s_o, s_i instruction.
This patch also cleans up the SIOptimizeExecMasking pass a bit.
Reviewed By: nhaehnle
Differential Revision: https://reviews.llvm.org/D129073
The WWM register has unmodeled register liveness, For v_set_inactive_*,
clobberring source register is dangerous because it will overwrite the
inactive lanes. When the source vgpr is dead at v_set_inactive_lane,
the inactive lanes may be not really dead. This may make common
optimizations doing wrong.
For example in a simple if-then cfg in Machine IR:
bb.if:
%src =
bb.then:
%src1 = COPY %src
%dst = V_SET_INACTIVE %src1(tied-def 0), %inactive
bb.end
... = PHI [0, %bb.then] [%src, %bb.if]
The register coalescer will think it is safe to optimize "%src1 = COPY %src"
in bb.then. And at the same time, there is no interference for the PHI in
bb.end. The source and destination values of the PHI will be assigned
the same register. The single PHI register will be overwritten by the
v_set_inactive, then we would get wrong value in bb.end.
With this change, we will copy the content of the source register before
setting inactive lanes after register allocation. Yes, this will sacrifice
the WWM code generation a little, but I don't have any better idea to do things
correctly.
Differential Revision: https://reviews.llvm.org/D117482
