SIInsertWaitcnts inserts waitcnt instructions to resolve data
dependencies. The GFX10+ vscnt (VMEM store count) counter is never used
in this way. It is only used to resolve memory dependencies, and that is
handled by SIMemoryLegalizer. Hence there is no need to conservatively
wait for vscnt to be 0 on function entry and before returns.
Differential Revision: https://reviews.llvm.org/D153537
There is a failure with this pass in the case when target register class for a subregister isn't known from instruction description (for ex. COPY).
Currently in this situation the RC is obtained using TargetRegisterInfo::getSubRegisterClass but in general it's not working.
In order to fix this two things should be done:
1. Stop processing a subregister if the target register class is unknown (conservative approach)
2. Improve deduction of subregister' target register class (i.e by processing COPY chain)
I was going to implement point 1 but my tests use implicit operands for S_NOP and they don't have associated target register class and all tests fail.
Therefore I decided to turn off the pass now, implement point 1 and fix my tests.
Reviewed By: arsenm, #amdgpu
Differential Revision: https://reviews.llvm.org/D152291
The main purpose of this is to simplify register pressure tracking as after the pass there is no need
to track subreg liveness anymore.
On the other hand this pass creates more possibilites for the subreg unaware code, as many of the subregs
becomes ordinary registers.
Intersting sideeffect: spill-vgpr.ll has lost a lot of spills.
Reviewed By: #amdgpu, arsenm
Differential Revision: https://reviews.llvm.org/D139732
This reverts commit e8b3ffa532b8ebac5dcdf17bb91b47817382c14d.
The AMDGPU/mad_64_32.ll seems to fail on some of the build bots but
passes locally. I'm really confused.
(sra X, BW-1) is either 0 or -1. So the multiply is a conditional
negate of Y.
This pattern shows up when type legalizing wide multiplies involving
a sign extended value.
Fixes PR57549.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D133399
This reverts commit 0148df8157f05ecf3b1064508e6f012aefb87dad.
Getting a lit test failures on AMDGPU but I can't reproduce it so far.
Reverting to investigate.
(sra X, BW-1) is either 0 or -1. So the multiply is a conditional
negate of Y.
This pattern shows up when type legalizing wide multiplies involving
a sign extended value.
Fixes PR57549.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D133399
We form VOPD instructions in the GCNCreateVOPD pass by combining
back-to-back component instructions. There are strict register
constraints for creating a legal VOPD, namely that the matching operands
(e.g. src0x and src0y, src1x and src1y) must be in different register
banks. We add a PostRA scheduler
mutation to put possible VOPD components back-to-back.
Depends on D128442, D128270
Reviewed By: #amdgpu, rampitec
Differential Revision: https://reviews.llvm.org/D128656
GFX11 has a new message type MSG_DEALLOC_VGPRS which can be used to
release a shader's VGPRs. Sending this at the end of a shader (just
before the s_endpgm) can help overall system performance in cases where
the s_endpgm would have to wait for outstanding VMEM stores to complete
before releasing the VGPRs.
Differential Revision: https://reviews.llvm.org/D128442
GFX11 uses different pseudos for these because of a new constraint
on which operands' registers can overlap.
Differential Revision: https://reviews.llvm.org/D127659
Nic Curtis done the experiments to prove it is faster than a
separate mul and add.
Fixes: SWDEV-332806
Differential Revision: https://reviews.llvm.org/D127253
Only fold for uniform values on pre-GFX9 chips. GFX9+ allow us
to keep the calculation entirely on the SALU.
For subtargets where integer multiplication isn't full-rate, avoid
folding if the multiply has too many uses.
Finally, we expand 64x32 and 64x64 multiplies here as well, if they
feed into an addition. This results in better code generation than
the generic expansion for such multiplies because we end up using
the accumulator of the MAD instructions.
Differential Revision: https://reviews.llvm.org/D123835
Select SelectionDAG ops smul_lohi/umul_lohi to
v_mad_i64_i32/v_mad_u64_u32 respectively, with an addend of 0.
v_mul_lo, v_mul_hi and v_mad_i64/u64 are all quarter-rate instructions
so it is better to use one instruction than two.
Further improvements are possible to make better use of the addend
operand, but this is already a strict improvement over what we have
now.
Differential Revision: https://reviews.llvm.org/D113986
Make the FP register callee saved.
This is tricky because now the FP needs to be spilled in the prolog
relative to the incoming SP register, rather than the frame register
used throughout the rest of the function. I don't like how this
bypassess the standard mechanism for CSR spills just to get the
correct insert point. I may look for a better solution, since all CSR
VGPRs may also need to have all lanes activated. Another option might
be to make getFrameIndexReference change the base register if the
frame index is a CSR, and then try to figure out the right insertion
point in emitProlog.
If there is a free VGPR lane available for SGPR spilling, try to use
it for the FP. If that would require intrtoducing a new VGPR spill,
try to use a free call clobbered SGPR. Only fallback to introducing a
new VGPR spill as a last resort.
This also doesn't attempt to handle SGPR spilling with scalar stores.
llvm-svn: 365372
Use VOP3 add/addc like usual.
This has some tradeoffs. Inline immediates fold
a little better, but other constants are worse off.
SIShrinkInstructions could be made smarter to handle
these cases.
This allows us to avoid selecting scalar adds where we
need to track the carry in scc and replace its users.
This makes it easier to use the carryless VALU adds.
llvm-svn: 318340
