This was never used, and the only thing it changed was removed in
284472be6da3353d81dfd25b1ac4218e852d1e5f. The floating point mode is
also not a property of the subtarget.
Summary:
PHIs result register class is set to VGPR or SGPR depending on the cross block value divergence.
In some cases uniform PHI need to be converted to return VGPR to prevent the oddnumber of moves values from VGPR to SGPR and back.
PHI should certainly return VGPR if it has at least one VGPR input. This change adds the exception.
We don't want to convert uniform PHI to VGPRs in case the only VGPR input is a VGPR to SGPR COPY and definition od the
source VGPR in this COPY is move immediate.
bb.0:
%0:vgpr_32 = V_MOV_B32_e32 0, implicit $exec
%2:sreg_32 = .....
bb.1:
%3:sreg_32 = PHI %1, %bb.3, %2, %bb.1
S_BRANCH %bb.3
bb.3:
%1:sreg_32 = COPY %0
S_BRANCH %bb.2
Reviewers: rampitec
Reviewed By: rampitec
Subscribers: arsenm, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80434
OpenMP emits these for some reason, so handle them. Assume these use
4096 bytes by default, with a flag to override this. Also change the
related stack assumption for calls to have a flag.
We do not have register classes for all possible vector
sizes, so round it up for extract vector element.
Also fixes selection of G_MERGE_VALUES when vectors are
not a power of two.
This has required to refactor getRegSplitParts() in way
that it can handle not just power of two vectors.
Ideally we would like RegSplitParts to be generated by
tablegen.
Differential Revision: https://reviews.llvm.org/D80457
- This allow us to specify the (minimal) alignment on an intrinsic's
arguments and, more importantly, the return value.
Differential Revision: https://reviews.llvm.org/D80422
This is the groundwork required to implement strictfp. For now, this
should be NFC for regular instructoins (many instructions just gain an
extra use of a reserved register). Regalloc won't rematerialize
instructions with reads of physical registers, but we were suffering
from that anyway with the exec reads.
Should add it for all the related FP uses (possibly with some
extras). I did not add it to either the gpr index mode instructions
(or every single VALU instruction) since it's a ridiculous feature
already modeled as an arbitrary side effect.
Also work towards marking instructions with FP exceptions. This
doesn't actually set the bit yet since this would start to change
codegen. It seems nofpexcept is currently not implied from the regular
IR FP operations. Add it to some MIR tests where I think it might
matter.
All 3 passes that change instruction encodings were dropping MI
flags. This avoids scheduling regressions caused by setting
mayRaiseFPExceptions on FP instructions for non-strictfp functions.
The vector equivalent has backwards operands, but the scalar version
does not. The passes that use these hooks aren't enabled by default,
so this doesn't really change anything.
I'm guessing this was a holdover from when 0 was an invalid stack
pointer, but surprised nobody has discovered this before.
Also don't allow offset folding for -1 pointers, since it looks weird
to partially fold this.
I consider this to be a hack, since we probably should not mark any
16-bit extract as legal, and require all extracts to be done on
multiples of 32. There are quite a few more battles to fight in the
legalizer for sub-dword vectors, so just select this for now so we can
pass OpenCL conformance without crashing.
Also fix the same assert for G_INSERTs. Unlike G_EXTRACT there's not a
trivial way to select this so just fail on it.
Confusingly, these were unrelated and had different semantics. The
G_PTR_MASK instruction predates the llvm.ptrmask intrinsic, but has a
different format. G_PTR_MASK only allows clearing the low bits of a
pointer, and only a constant number of bits. The ptrmask intrinsic
allows an arbitrary mask. Replace G_PTR_MASK to match the intrinsic.
Only selects the cases that look like the old instruction. More work
is needed to select the general case. Also new legalization code is
still needed to deal with the case where the incoming mask size does
not match the pointer size, which has a specified behavior in the
langref.
This is currently missing most of the hard parts to lower correctly,
so disable it for now. This fixes at least one OpenCL conformance test
and allows it to pass with fallback. Hide this behind an option for
now.
Summary: 'A' constraint requires an immediate int or fp constant that can be inlined in an instruction encoding.
Reviewers: arsenm, rampitec
Differential Revision: https://reviews.llvm.org/D78494
EarlyCSE was added with D75145, but the motivating test is
not regressed by removing the extra pass now. That might be
because VectorCombine altered the way it processes instructions,
or it might be from (re)moving VectorCombine in the pipeline.
The extra round of EarlyCSE appears to cost approximately
0.26% in compile-time as discussed in D80236, so we need some
evidence to justify its inclusion here, but we do not have
that (yet).
I suspect that between SLP and VectorCombine, we are creating
patterns that InstCombine and/or codegen are not prepared for,
but we will need to reduce those examples and include them as
PhaseOrdering and/or test-suite benchmarks.
As noted in D80236, moving the pass in the pipeline exposed this
shortcoming. Extra work to recalculate the alias results showed
up as a compile-time slowdown.
There are 2 known problem patterns shown in the test diffs here:
vector horizontal ops (an x86 specialization) and vector reductions.
SLP has greater ability to match and fold those than vector-combine,
so let SLP have first chance at that.
This is a quick fix while we continue to improve vector-combine and
possibly canonicalize to reduction intrinsics.
In the longer term, we should improve matching of these patterns
because if they were created in the "bad" forms shown here, then we
would miss optimizing them.
I'm not sure what is happening with alias analysis on the addsub test.
The old pass manager now shows an extra line for that, and we see an
improvement that comes from SLP vectorizing a store. I don't know
what's missing with the new pass manager to make that happen.
Strangely, I can't reproduce the behavior if I compile from C++ with
clang and invoke the new PM with "-fexperimental-new-pass-manager".
Differential Revision: https://reviews.llvm.org/D80236
Unlike SelectionDAGBuilder, IRTranslator omits the unconditional
branch in fallthrough cases. Confusingly, the control flow pseudos
function in the opposite way the intrinsics are used, and the branch
targets always need to be swapped. We're inverting the target blocks,
so we need to figure out the old fallthrough block and insert a branch
to the original unconditional branch target.
This only affects assembly and -filetype=asm codegen of PAL metadata.
Differential Revision: https://reviews.llvm.org/D78860
Change-Id: I7b822e1917bf7b403486820d31afc483be207652
Promote alloca to vector before SROA and loop unroll. If we manage
to eliminate allocas before unroll we may choose to unroll less.
Differential Revision: https://reviews.llvm.org/D80386
It was set in total vector size while the idea was to limit
a number of instructions. Now it started to work with doubles
and thresholds needs to be updated.
Differential Revision: https://reviews.llvm.org/D80322
Even though series of cmd/cndmask can produce quite a lot of
code that is still better than a loop. In case of doubles we
would even produce two loops.
Differential Revision: https://reviews.llvm.org/D80032
Relying on any MachineFunction state in the MachineFunctionInfo
constructor is hazardous, because the construction time is unclear and
determined by the first use. The function may be only partially
constructed, which is part of why we have many of these hacky string
attributes to track what we need for ABI lowering.
For SelectionDAG, all stack objects are created up-front before
calling convention lowering so stack objects are visible at
construction time. For GlobalISel, none of the IR function has been
visited yet and the allocas haven't been added to the MachineFrameInfo
yet. This should fix failing to set flat_scratch_init in GlobalISel
when needed.
This pass really needs to be turned into some kind of analysis, but I
haven't found a nice way use one here.
This should be directly implied from the register class, and there's
no need to special case live ins here. This was getting the wrong
answer for the queue ptr argument in callable functions, since it's
not an explicit IR argument and is always uniform.
Fixes not using scalar loads for the aperture in addrspacecast
lowering, and any other places that use implicit SGPR arguments.
This was assumed to be a simple move, and interpreting the immediate
modifier operand as a materialized immediate. Apparently the SDWA pass
never produces these, but GlobalISel does emit these for some vector
shuffles.