Part of the code related to ds_read/ds_write ISel is refactored, and the
corresponding comment is re-written for better readability, which would help
while implementing any future ds_read/ds_write ISel related modifications.
Reviewed By: rampitec
Differential Revision: https://reviews.llvm.org/D100300
Move some utility functions which are used within LDS lowering pass to a separate utils
file so that other LDS related passes can make use of them when required.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D100526
Being lazy with printing the banner seems hard to reason with, we should print it
unconditionally first (it could also lead to duplicate banners if we
have multiple functions in -filter-print-funcs).
The printIR() functions were doing too many things. I separated out the
call from PrintPassInstrumentation since we were essentially doing two
completely separate things in printIR() from different callers.
There were multiple ways to generate the name of some IR. That's all
been moved to getIRName(). The printing of the IR name was also
inconsistent, now it's always "IR Dump on $foo" where "$foo" is the
name. For a function, it's the function name. For a loop, it's what's
printed by Loop::print(), which is more detailed. For an SCC, it's the
list of functions in parentheses. For a module it's "[module]", to
differentiate between a possible SCC with a function called "module".
To preserve D74814, we have to check if we're going to print anything at
all first. This is unfortunate, but I would consider this a special
case that shouldn't be handled in the core logic.
Reviewed By: jamieschmeiser
Differential Revision: https://reviews.llvm.org/D100231
Returning in memory is not supported, so fall back to sret.
Also, extend i1 and i16 to i32. Otherwise, they would be passed through
memory.
Differential Revision: https://reviews.llvm.org/D100543
Now since LDS uses within non-kernel functions are being handled in the
pass - LowerModuleLDS, we *NO* need to *forcefully* inline non-kernel
functions just because they use LDS. Do forceful inlining only when the
pass - LowerModuleLDS is not enabled. It is enabled by default.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D100481
This is a service function generally useful for selection
of a FI in an SADDR. NFC for now, needed for future patch.
Differential Revision: https://reviews.llvm.org/D100406
Rename the name of "LDS lowering" pass from `amdgpu-disable-lower-module-lds` to
`amdgpu-enable-lower-module-lds` as later is consistent and reads better.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D100441
Otherwise it reuses the same register for storing the stack slot
offset if the stack slot offset is big.
Differential Revision: https://reviews.llvm.org/D100461
This patch adds attributes corresponding to
implicits to functions/kernels if
1. it has an indirect call OR
2. it's address is taken.
Once such attributes are set, rest of the codegen would work
out-of-box for indirect calls. This patch eliminates
the potential overhead -fixed-abi imposes even though indirect functions
calls are not used.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D99347
Spilling the fp or bp to scratch could overwrite VGPRs of inactive
lanes. Fix that by using only the active lanes of the scavenged VGPR.
This builds on the assumptions that
1. a function is never called with exec=0
2. lanes do not die in a function, i.e. exec!=0 in the function epilog
3. no new lanes are active when exiting the function, i.e. exec in the
epilog is a subset of exec in the prolog.
Differential Revision: https://reviews.llvm.org/D96869
Spilling SGPRs to scratch uses a temporary VGPR. LLVM currently cannot
determine if a VGPR is used in other lanes or not, so we need to save
all lanes of the VGPR. We even need to save the VGPR if it is marked as
dead.
The generated code depends on two things:
- Can we scavenge an SGPR to save EXEC?
- And can we scavenge a VGPR?
If we can scavenge an SGPR, we
- save EXEC into the SGPR
- set the needed lane mask
- save the temporary VGPR
- write the spilled SGPR into VGPR lanes
- save the VGPR again to the target stack slot
- restore the VGPR
- restore EXEC
If we were not able to scavenge an SGPR, we do the same operations, but
everytime the temporary VGPR is written to memory, we
- write VGPR to memory
- flip exec (s_not exec, exec)
- write VGPR again (previously inactive lanes)
Surprisingly often, we are able to scavenge an SGPR, even though we are
at the brink of running out of SGPRs.
Scavenging a VGPR does not have a great effect (saves three instructions
if no SGPR was scavenged), but we need to know if the VGPR we use is
live before or not, otherwise the machine verifier complains.
Differential Revision: https://reviews.llvm.org/D96336
Added cost estimation for switch instruction, updated costs of branches, fixed
phi cost.
Had to increase `-amdgpu-unroll-threshold-if` default value since conditional
branch cost (size) was corrected to higher value.
Test renamed to "control-flow.ll".
Removed redundant code in `X86TTIImpl::getCFInstrCost()` and
`PPCTTIImpl::getCFInstrCost()`.
Reviewed By: rampitec
Differential Revision: https://reviews.llvm.org/D96805
Remove the MachineDCE pass after the first SIFoldOperands pass now
that SIFoldOperands deletes its own dead instructions.
Differential Revision: https://reviews.llvm.org/D100189
This is cheap to implement, means less work for future passes like
MachineDCE, and slightly improves the folding in some cases.
Differential Revision: https://reviews.llvm.org/D100117
Use SIInstrFlags to differentiate between the different
variants of flat instructions (flat, global and scratch).
This should make it easier to bundle the immediate offset logic in a
single place and implement restrictions and bug workarounds.
Fixed version of D99587, which does not rely on the address space.
Differential Revision: https://reviews.llvm.org/D99743
Main reason is preparation to transform AliasResult to class that contains
offset for PartialAlias case.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D98027
It used to work correctly even with a KILL, but there is
no reason to consider meta instructions since they do not
create real HW uses.
Differential Revision: https://reviews.llvm.org/D100135
Look through copies to find more cases where the two values being
selected are identical. The motivation for this is just to be able to
remove the weird special case where tryFoldCndMask was called from
foldInstOperand, part way through folding a move-immediate into its
users, without regressing any lit tests.
ScratchExecCopy needs to be marked as live, we cannot use that register
while EXEC is stored in there.
Marking SGPRForFPSaveRestoreCopy and SGPRForBPSaveRestoreCopy as
available is unnecessary, they should not be live at that point anway.
Differential Revision: https://reviews.llvm.org/D100098
Allow pass to work separately with SGPR, VGPR registers or both.
This is NFC now but will be needed to split RA for separate
SGPR and VGPR passes.
Differential Revision: https://reviews.llvm.org/D100063
The struct is used for both, callee and caller-save registers now.
The frame index is not set for entrypoints, as we do not need to save
the registers then.
Update the struct name to reflect that.
Differential Revision: https://reviews.llvm.org/D99722
This fixes an oversight in D99747 which moved the IMG init code from
SIAddIMGInit to AdjustInstrPostInstrSelection, but did not set the
hasPostISelHook flag on gather4 instructions.
Differential Revision: https://reviews.llvm.org/D99953
Doing this during instruction selection avoids the cost of running
SIAddIMGInit which is yet another pass over the MIR.
Differential Revision: https://reviews.llvm.org/D99670
Doing this in a post-isel hook avoids the cost of running SIAddIMGInit
which is yet another pass over the MIR.
Differential Revision: https://reviews.llvm.org/D99747
By convention, VOP1/2/C instructions which can be promoted to VOP3 have _e32 suffix while promoted instructions have _e64 suffix. Instructions which have a single variant should have no _e32/_e64 suffix. Unfortunately there was no simple way to identify single variant instructions - it was implemented by a hack. See bug https://bugs.llvm.org/show_bug.cgi?id=39086.
This fix simplifies handling of single VOP instructions by adding a dedicated flag.
Differential Revision: https://reviews.llvm.org/D99408
This includes gfx908 which only has a no-return version of the
global_atomic_add_f32 instruction, using the same hack that was
previously implemented for selecting from the
llvm.amdgcn.global.atomic.fadd intrinsic.
Differential Revision: https://reviews.llvm.org/D97767
Currently needsStackRealignment returns false if canRealignStack returns false.
This means that the behavior of needsStackRealignment does not correspond to
it's name and description; a function might need stack realignment, but if it
is not possible then this function returns false. Furthermore,
needsStackRealignment is not virtual and therefore some backends have made use
of canRealignStack to indicate whether a function needs stack realignment.
This patch attempts to clarify the situation by separating them and introducing
new names:
- shouldRealignStack - true if there is any reason the stack should be
realigned
- canRealignStack - true if we are still able to realign the stack (e.g. we
can still reserve/have reserved a frame pointer)
- hasStackRealignment = shouldRealignStack && canRealignStack (not target
customisable)
Targets can now override shouldRealignStack to indicate that stack realignment
is required.
This change will make it easier in a future change to handle the case where we
need to realign the stack but can't do so (for example when the register
allocator creates an aligned spill after the frame pointer has been
eliminated).
Differential Revision: https://reviews.llvm.org/D98716
Change-Id: Ib9a4d21728bf9d08a545b4365418d3ffe1af4d87
Note, only src0 and src1 will be commuted if the isCommutable flag
is set. This patch does not change that, it just makes it possible
to commute src0 and src1 of more instructions.
Reviewed By: foad, rampitec
Differential Revision: https://reviews.llvm.org/D99376
Change-Id: I61e20490962d95ea429beb355c55f55c024dafdc
If the result of an atomic operation is not used then it can be more
efficient to build a reduction across all lanes instead of a scan. Do
this for GFX10, where the permlanex16 instruction makes it viable. For
wave64 this saves a couple of dpp operations. For wave32 it saves one
readlane (which are generally bad for performance) and one dpp
operation.
Differential Revision: https://reviews.llvm.org/D98953
This patch changes the interface to take a RegisterKind, to indicate
whether the register bitwidth of a scalar register, fixed-width vector
register, or scalable vector register must be returned.
Reviewed By: paulwalker-arm
Differential Revision: https://reviews.llvm.org/D98874
Folding EXEC copy into it's single use may lead to constant bus constraint violation as it adds one more SGPR operand.
This change makes it validate the user instruction with the new SGPR operand and only fold it if it is legal.
Reviewed By: rampitec, arsenm
Differential Revision: https://reviews.llvm.org/D98888
NFC. Extract IsShrinkable into a helper function, and
make Subtarget a member variable.
Reviewed By: rampitec
Differential Revision: https://reviews.llvm.org/D99099
Change-Id: If4bc97a88a9ae4eb1df47e717345d46a6ed515bf
Coyp SchedRW from pseudos to real instructions so that llvm-mca has
access to it. This is NFC for normal compiler codegen, which schedules
pseudos not real instructions.
Add an llvm-mca test for some high latency double-precision instructions
as a smoke test.
Differential Revision: https://reviews.llvm.org/D99187
This restores previous behaviour and is a step toward removing
unbundling entirely.
Reviewed By: foad, rampitec
Differential Revision: https://reviews.llvm.org/D99061
The pseudo was using SSrc_b64, so it allowed folding immediates into
the destination operand for a tail call to null. However, this is not
a valid operand for the s_setpc_b64 this will be lowered to. Avoids
printing the operand as an invalid immediate.
Avoids a regression when tail calls are enabled in GlobalISel (somehow
tail calls to null get deleted in the DAG).
Pass no longer handles skips. Pass now removes unnecessary
unconditional branches and lowers early termination branches.
Hence rename to SILateBranchLowering.
Move code to handle returns to epilog from SIPreEmitPeephole
into SILateBranchLowering. This means SIPreEmitPeephole only
contains optional optimisations, and all required transforms
are in SILateBranchLowering.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D98915
SIRemoveShortExecBranches is an optimisation so fits well in the
context of SIPreEmitPeephole.
Test changes relate to early termination from kills which have now
been lowered prior to considering branches for removal.
As these use s_cbranch the execz skips are now retained instead.
Currently either behaviour is valid as kill with EXEC=0 is a nop;
however, if early termination is used differently in future then
the new behaviour is the correct one.
Reviewed By: foad
Differential Revision: https://reviews.llvm.org/D98917
Add code so duplication index register changes can be removed from
inside bundles.
Reviewed By: rampitec, foad
Differential Revision: https://reviews.llvm.org/D98940
[amdgpu] Update med3 combine to skip i64
Fixes an assumption that a type which is not i32 will be i16. This asserts
when trying to sign/zero extend an i64 to i32.
Test case was cut down from an openmp application. Variations on it are hit by
other combines before reaching the problematic one, e.g. replacing the
immediate values with other function arguments changes the codegen path and
misses this combine.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D98872
Avoid revisiting nodes with the same set of defined lanes by
using a unified visited set which integrates lanes into the key.
This retains the intent of the original code by still revisiting
a subgraph if a different set of lanes is defined and hence
marking might progress differently.
Note: default size of the visited set has been confirmed to
cover >99% of invocations in large array of test shaders.
Reviewed By: piotr
Differential Revision: https://reviews.llvm.org/D98772
Joe Nash