Summary:
Instead of generating two i32 instructions for each load or store of a volatile
i64 value (two LDRs or STRs), now emit LDRD/STRD.
These improvements cover architectures implementing ARMv5TE or Thumb-2.
The code generation explicitly deviates from using the register-offset
variant of LDRD/STRD. In this variant, the register allocated to the
register-offset cannot be reused in any of the remaining operands. Such
restriction seems to be non-trivial to implement in LLVM, thus it is
left as a to-do.
Reviewers: dmgreen, efriedma, john.brawn, nickdesaulniers
Reviewed By: efriedma, nickdesaulniers
Subscribers: danielkiss, alanphipps, hans, nathanchance, nickdesaulniers, vvereschaka, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70072
This avoids regressions in a future patch. I'm confused by the use of
the gfx9 usage legacy_mad. Was this a pointless instruction rename, or
uses fmul_legacy handling? Why is regular mac avilable in that case?
Summary:
As far as I can tell on gfx10 conversions to/from f32 (that are not
converting f32 to/from f64) are full rate instructions, but they were
marked as quarter rate instructions.
I have fixed this for gfx10 only. I assume the scheduling model was
correct for older architectures, though I don't have any documentation
handy to confirm that.
Reviewers: rampitec, arsenm
Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75392
Summary:
This patch extends the TargetMachine to let targets specify the integer size
used by the sjljehprepare pass. This is 64bit for the VE target and otherwise
defaults to 32bit for all targets, which was hard-wired before.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D71337
In case the source value ends up in a VGPR, insert a readfirstlane to
avoid producing an illegal copy later. If it turns out to be
unnecessary, it can be folded out.
Swap the compare operands if LHS is spilled while updating the CCMask:s of
the CC users. This is relatively straight forward since the live-in lists for
the CC register can be assumed to be correct during register allocation
(thanks to 659efa2).
Also fold a spilled operand of an LOCR/SELR into an LOC(G).
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D67437
Summary:
When SI_INDIRECT_DST_V* pseudos has indexes in VGPR, they get expanded into the self-looped basic block that modifies EXEC in a loop.
To keep EXEC consistent it is stored before and then re-stored after the pseudo expansion result.
%95:vreg_512 = SI_INDIRECT_DST_V16 %93:vreg_512(tied-def 0), %94:sreg_32, 0, killed %1500:vgpr_32
results to
s_mov_b64 s[6:7], exec
BB0_16:
v_readfirstlane_b32 s8, v28
v_cmp_eq_u32_e32 vcc, s8, v28
s_and_saveexec_b64 vcc, vcc
s_set_gpr_idx_on s8, gpr_idx(DST)
v_mov_b32_e32 v6, v25
s_set_gpr_idx_off
s_xor_b64 exec, exec, vcc
s_cbranch_execnz BB0_16
; %bb.17:
s_mov_b64 exec, s[6:7]
The bug appeared in case this expansion occurs in the ELSE block of the CF.
Originally
%110:vreg_512 = SI_INDIRECT_DST_V16 %103:vreg_512(tied-def 0), %85:vgpr_32, 0, %107:vgpr_32,
%112:sreg_64 = SI_ELSE %108:sreg_64, %bb.19, 0, implicit-def dead $exec, implicit-def dead $scc, implicit $exec
expanded to
****************** <== here exec has "THEN" context
s_mov_b64 s[6:7], exec
BB0_16:
v_readfirstlane_b32 s8, v28
v_cmp_eq_u32_e32 vcc, s8, v28
s_and_saveexec_b64 vcc, vcc
s_set_gpr_idx_on s8, gpr_idx(DST)
v_mov_b32_e32 v6, v25
s_set_gpr_idx_off
s_xor_b64 exec, exec, vcc
s_cbranch_execnz BB0_16
; %bb.17:
s_or_saveexec_b64 s[4:5], s[4:5] <-- exec mask is restored for "ELSE" but immediately overwritten.
s_mov_b64 exec, s[6:7]
The rest of the "ELSE" block is executed not by the workitems which constitute the "else mask" but by those which constitute "then mask"
SILowerControlFlow::emitElse always considers the basic block begin() as an insertion point for s_or_saveexec.
Proposed fix: The SI_INDIRECT_DST_V* procedure should split the reminder block to create landing pad for the EXEC restoration.
Reviewers: rampitec, vpykhtin, nhaehnle
Reviewed By: vpykhtin
Subscribers: arsenm, kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, t-tye, hiraditya, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75472
On some Arm cores there is a performance penalty when forwarding from an
S register to a D register. Calculating VMAX in a D register creates
false forwarding hazards, so don't do that unless we're on a core which
specifically asks for it.
Patch by James Greenhalgh
Differential Revision: https://reviews.llvm.org/D75248
For pre-AVX512 targets, combine binary shuffles to X86ISD::VPERM2X128 if possible. This mainly helps optimize the blend(extract_subvector(x,1),y) pattern.
At some point soon we're going to have make a decision about when to combine AVX512 shuffles more aggressively - we bail out if there is any change in element size (to protect predicate mask merging) which means we miss out on a lot of optimizations.
Iterate through the loop and check that the observable values
produced are the same whether tail predication happens or not.
We want to find out if the tail-predicated version of this loop will
produce the same values as the loop in its original form. For this to
be true, the newly inserted implicit predication must not change the
the (observable) results.
We're doing this because many instructions in the loop will not be
predicated and so the conversion from VPT predication to tail
predication can result in different values being produced, because of
falsely predicated lanes not being updated in the converted form.
A masked load, whether through VPT or tail predication, will write
zeros to any of the falsely predicated bytes. So, from the loads, we
know that the false lanes are zeroed and here we're trying to track
that those false lanes remain zero, or where they change, the
differences are masked away by their user(s).
All MVE loads and stores have to be predicated, so we know that any
load operands, or stored results are equivalent already. Other
explicitly predicated instructions will perform the same operation in
the original loop and the tail-predicated form too. Because of this,
we can insert loads, stores and other predicated instructions into
our KnownFalseZeros set and build from there.
Differential Revision: https://reviews.llvm.org/D75452
isTypeDesirableForOp prevents loads from being shrunk to i16 by DAG
combine. Because of this we can't just match the broadcast and a
scalar load. So look for broadcast+truncate+load and form a
vbroadcast_load during DAG combine. This replaces what was
previously done as an isel pattern and I think fixes it so we
won't change the size of a volatile load. But my main motivation
is just to clean up our isel patterns.
When expanding scalar packed operations, we should not introduce
illegal vector casts LegalizerHelper introduces. We're not in a
legalizer context, and there's no RegBankSelect apply or legalize
worklist.
We weren't considering the packed case correctly, and this was passing
through to the selector. The selector only checked the size, so this
would incorrectly compile to a single 32-bit scalar add.
As usual, the LegalizerHelper is somewhat awkward to use from
applyMappingImpl. I think this is the first place we've needed
multi-step legalization here though.
Summary:
Fixes: https://bugs.llvm.org/show_bug.cgi?id=44920
WebAssemblyRegColoring may merge the vreg that currently represents
the FrameBase with one representing an argument.
WebAssemblyExplicitLocals picks up the corresponding local when
a vreg is first added to the Reg2Local mapping, except when it is
an argument instruction which are handled separately.
Note that this does not change that vregs representing the FrameBase
may get merged, it is not clear to me that this may have other
effects we may want to avoid?
Reviewers: dschuff
Reviewed By: dschuff
Subscribers: azakai, sbc100, hiraditya, aheejin, sunfish, llvm-commits, jgravelle-google
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75718
Patch by Zola Bridges!
From the review:
"""
I moved these functions to X86InstrInfo.cpp, so they are available from
another pass. In addition, this is a step toward resolving the FIXME to
move this metadata to the instruction tables.
This is the final step to make these two data invariance checks
available for non-SLH passes.
The other two steps were here:
- https://reviews.llvm.org/D70283
- https://reviews.llvm.org/D75650
Tested via llvm-lit llvm/test/CodeGen/X86/speculative-load-hardening*
"""
Differential Revision: https://reviews.llvm.org/D75654
Patch by Zola Bridges!
From the review:
"""
In this changeset (https://reviews.llvm.org/D70283), I added a liveness
check everywhere the isDataInvariant* functions were used, so that I
could safely delete the checks within the function. I mistakenly left
that deletion out of the patch. The result is that the same condition is
checked twice for some instructions which is functionally fine, but not
good. This change deletes the redundant check that I intended to delete
in the last change.
This is the second of three patches that will make the data invariance
checks available for non-SLH passes and enable the FIXMEs related to
moving this metadata to the instruction tables to be resolved.
Tested via llvm-lit llvm/test/CodeGen/X86/speculative-load-hardening*
"""
Differential Revision: https://reviews.llvm.org/D75650
Summary:
Instruction variants like S_MOV_B32_term should have the same SchedRW
class as the base instruction, S_MOV_B32. This probably doesn't make any
difference in practice because as terminators, they'll always be
scheduled at the end of a basic block, but it's simply more correct than
giving them all the default SchedRW class of Write32Bit, which implies a
VALU operation.
Reviewers: rampitec, arsenm, nhaehnle
Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, t-tye, hiraditya, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75860
Most importantly, this fixes ret i8. Also make sure to handle
signext/zeroext for odd types > i32. Some of the corresponding
argument passing fixes also need to be handled.
Interpret these as extending to the next multiple of 32-bits. This had
no effect with i48 for example, which is really split into {i32, i16},
which should extend the high part.
Use a hack to only enable this for GlobalISel.
Technically this also works with SelectionDAG, but the divergence
selection isn't reliable enough and a few cases fail, but I have no
desire to spend time writing the manual expansion code for it. The DAG
actually does a better job since it catches using v_add_lshl_u32 in
the mixed SGPR/VGPR cases.
If we don't need the upper subvector elements of the BLENDI node then use a smaller vector size.
This causes a couple of minor regressions in insertelement-ones.ll which are more examples of PR26018; given how cheap allones generation is I don't consider that a showstopper, just an annoyance (and there's plenty of other poor codegen cases in that file).
If we're inserting a scalar that is smaller than the element
size of the final VT, the value of the extra bits doesn't matter.
Previously we any_extended in the scalar domain before inserting.
This patch changes this to use a broadcast of the original
scalar type and then a bitcast to the final type. This might
enable the use of a broadcast load.
This recovers regressions from 07d68c24aa
and 9fcd212e2f without relying on
alignment of the load.
Differential Revision: https://reviews.llvm.org/D75835
The patch fixes some typos and introduces ReadFMemBase, ReadFSGNJ32,
ReadFSGNJ64, WriteFSGNJ32, WriteFSGNJ64, ReadFMinMax32, ReadFMinMax64,
WriteFMinMax32, WriteFMinMax64, so the target CPU with different pipeline model
could use them to describe latency.
Differential Revision: https://reviews.llvm.org/D75515
This was selecting VBROADCASTW which turned the 8-bit load into
a 16-bit load if it happened to be 2 byte aligned.
I have a plan to fix the regression with a follow up patch
which I'll post shortly.
In 172eee9c, we tried to avoid these by modelling the callee as
internally resetting the stack pointer.
However, for the majority of functions with reserved stack frames, this
would lead LLVM to emit extra SP adjustments to undo the callee's
internal adjustment. This lead us to fix the problem further on down the
pipeline in eliminateCallFramePseudoInstr. In 5b79e603d3, I added
use a heuristic to try to detect when the adjustment would be
unreachable.
This heuristic is imperfect, and when exception handling is involved, it
fails to fire. The new test is an example of this. Simply throwing an
exception with an active cleanup emits dead SP adjustments after the
throw. Not only are they dead, but if they were executed, they would be
incorrect, so they are confusing.
This change essentially reverts 172eee9c and makes the 5b79e603d3
heuristic responsible for preventing unreachable stack adjustments. This
means we may emit unreachable stack adjustments for functions using EH
with unreserved call frames, but that is not very many these days. Back
in 2016 when this change was added, we were focused on 32-bit, which we
observed to have fewer reserved frames.
Fixes PR45064
Reviewed By: hans
Differential Revision: https://reviews.llvm.org/D75712
There was a noop bitconvert in the load pattern. While there
also make all the sources refer to src_v.RC even though its the
same as _.RC, but its consistent.
Summary:
ARMAsmParser was incorrectly dropping a leading dollar sign character
from symbol names in targets of branch instructions. This was caused by
an incorrect assumption that the contents following the dollar sign
token should be handled as a constant immediate, similarly to the #
token.
This patch avoids the operand parsing from consuming the dollar sign
token when it is followed by an identifier, making sure it is properly
parsed as part of the expression.
Reviewers: efriedma
Reviewed By: efriedma
Subscribers: danielkiss, chill, carwil, vhscampos, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73176
Victor Campos