AMDGPU: Make various vector undefs legal

Surprisingly these were getting legalized to something
zero initialized.

This fixes an infinite loop when combining some vector types.
Also fixes zero initi

AMDGPU: Make various vector undefs legal

Surprisingly these were getting legalized to something
zero initialized.

This fixes an infinite loop when combining some vector types.
Also fixes zero initializing some undef values.

SimplifyDemandedVectorElts / SimplifyDemandedBits are not checking
for the legality of the output undefs they are replacing unused
operations with. This resulted in turning vectors into undefs
that were later re-legalized back into zero vectors.

(cherry picked from commit 7a84624079a2656c684bed6100708544500c5a32)

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[AMDGPU] Add GFX11 test coverage

Add GFX11 test coverage to a bunch of tests where it was easy to do so,
mostly because the checks are autogenerated and/or GFX11 can share the
same checks as GFX10.

[AMDGPU] Add GFX11 test coverage

Add GFX11 test coverage to a bunch of tests where it was easy to do so,
mostly because the checks are autogenerated and/or GFX11 can share the
same checks as GFX10.

Differential Revision: https://reviews.llvm.org/D129295

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[AMDGPU] Move call clobbered return address registers s[30:31] to callee saved range

Currently the return address ABI registers s[30:31], which fall in the call
clobbered register range, are added a

[AMDGPU] Move call clobbered return address registers s[30:31] to callee saved range

Currently the return address ABI registers s[30:31], which fall in the call
clobbered register range, are added as a live-in on the function entry to
preserve its value when we have calls so that it gets saved and restored
around the calls.

But the DWARF unwind information (CFI) needs to track where the return address
resides in a frame and the above approach makes it difficult to track the
return address when the CFI information is emitted during the frame lowering,
due to the involvment of understanding the control flow.

This patch moves the return address ABI registers s[30:31] into callee saved
registers range and stops adding live-in for return address registers, so that
the CFI machinery will know where the return address resides when CSR
save/restore happen during the frame lowering.

And doing the above poses an issue that now the return instruction uses undefined
register `sgpr30_sgpr31`. This is resolved by hiding the return address register
use by the return instruction through the `SI_RETURN` pseudo instruction, which
doesn't take any input operands, until the `SI_RETURN` pseudo gets lowered to the
`S_SETPC_B64_return` during the `expandPostRAPseudo()`.

As an added benefit, this patch simplifies overall return instruction handling.

Note: The AMDGPU CFI changes are there only in the downstream code and another
version of this patch will be posted for review for the downstream code.

Reviewed By: arsenm, ronlieb

Differential Revision: https://reviews.llvm.org/D114652

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[AMDGPU][NFC] Add autogenerated tests for vgpr-tuple-allocation.ll

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D117692

Revert "[AMDGPU] Move call clobbered return address registers s[30:31] to callee saved range"

This reverts commit 9075009d1fd5f2bf9aa6c2f362d2993691a316b3.

Failed amdgpu runtime buildbot # 3514

[AMDGPU] Move call clobbered return address registers s[30:31] to callee saved range

Currently the return address ABI registers s[30:31], which fall in the call
clobbered register range, are added a

[AMDGPU] Move call clobbered return address registers s[30:31] to callee saved range

Currently the return address ABI registers s[30:31], which fall in the call
clobbered register range, are added as a live-in on the function entry to
preserve its value when we have calls so that it gets saved and restored
around the calls.

But the DWARF unwind information (CFI) needs to track where the return address
resides in a frame and the above approach makes it difficult to track the
return address when the CFI information is emitted during the frame lowering,
due to the involvment of understanding the control flow.

This patch moves the return address ABI registers s[30:31] into callee saved
registers range and stops adding live-in for return address registers, so that
the CFI machinery will know where the return address resides when CSR
save/restore happen during the frame lowering.

And doing the above poses an issue that now the return instruction uses undefined
register `sgpr30_sgpr31`. This is resolved by hiding the return address register
use by the return instruction through the `SI_RETURN` pseudo instruction, which
doesn't take any input operands, until the `SI_RETURN` pseudo gets lowered to the
`S_SETPC_B64_return` during the `expandPostRAPseudo()`.

As an added benefit, this patch simplifies overall return instruction handling.

Note: The AMDGPU CFI changes are there only in the downstream code and another
version of this patch will be posted for review for the downstream code.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D114652

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AMDGPU: Enable fixed function ABI by default

Code using indirect calls is broken without this, and there isn't
really much value in supporting the old attempt to vary the argument
placement based on

AMDGPU: Enable fixed function ABI by default

Code using indirect calls is broken without this, and there isn't
really much value in supporting the old attempt to vary the argument
placement based on uses. This resulted in more argument shuffling code
anyway.

Also have the option stop implying all inputs need to be passed. This
will no rely on the amdgpu-no-* attributes to avoid passing
unnecessary values.

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[AMDGPU] Only allow implicit WQM in pixel shaders

Implicit derivatives are only valid in pixel shaders,
hence only implicitly enable WQM for pixel shaders.
This avoids unintended WQM in other shader

[AMDGPU] Only allow implicit WQM in pixel shaders

Implicit derivatives are only valid in pixel shaders,
hence only implicitly enable WQM for pixel shaders.
This avoids unintended WQM in other shader types (e.g. compute)
when image sampling instructions are used.

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D114414

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RegAlloc: Allow targets to split register allocation

AMDGPU normally spills SGPRs to VGPRs. Previously, since all register
classes are handled at the same time, this was problematic. We don't
know a

RegAlloc: Allow targets to split register allocation

AMDGPU normally spills SGPRs to VGPRs. Previously, since all register
classes are handled at the same time, this was problematic. We don't
know ahead of time how many registers will be needed to be reserved to
handle the spilling. If no VGPRs were left for spilling, we would have
to try to spill to memory. If the spilled SGPRs were required for exec
mask manipulation, it is highly problematic because the lanes active
at the point of spill are not necessarily the same as at the restore
point.

Avoid this problem by fully allocating SGPRs in a separate regalloc
run from VGPRs. This way we know the exact number of VGPRs needed, and
can reserve them for a second run. This fixes the most serious
issues, but it is still possible using inline asm to make all VGPRs
unavailable. Start erroring in the case where we ever would require
memory for an SGPR spill.

This is implemented by giving each regalloc pass a callback which
reports if a register class should be handled or not. A few passes
need some small changes to deal with leftover virtual registers.

In the AMDGPU implementation, a new pass is introduced to take the
place of PrologEpilogInserter for SGPR spills emitted during the first
run.

One disadvantage of this is currently StackSlotColoring is no longer
used for SGPR spills. It would need to be run again, which will
require more work.

Error if the standard -regalloc option is used. Introduce new separate
-sgpr-regalloc and -vgpr-regalloc flags, so the two runs can be
controlled individually. PBQB is not currently supported, so this also
prevents using the unhandled allocator.

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[AMDGPU] Add v5f32/VReg_160 support for MIMG instructions

Avoid having to round up to v8f32/VReg_256 when only 5 VGPRs are
required for a MIMG address operand.

Maintain _V8 instruction variants of

[AMDGPU] Add v5f32/VReg_160 support for MIMG instructions

Avoid having to round up to v8f32/VReg_256 when only 5 VGPRs are
required for a MIMG address operand.

Maintain _V8 instruction variants of pseudo instructions allowing
assembly prior to GFX10 to work as-is. Currently the validator
can tell for GFX10 what the correct size is, so will disallow
oversize address registers.

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D103672

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[AMDGPU] Set implicit arg attributes for indirect calls

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 su

[AMDGPU] Set implicit arg attributes for indirect calls

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

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Make fixed-abi default for AMD HSA OS

fixed-abi uses pre-defined and predictable
SGPR/VGPRs for passing arguments. This patch makes
this scheme default when HSA OS is specified in triple.

Reviewed

Make fixed-abi default for AMD HSA OS

fixed-abi uses pre-defined and predictable
SGPR/VGPRs for passing arguments. This patch makes
this scheme default when HSA OS is specified in triple.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D96340

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[AMDGPU] Stop adding an implicit def of vcc_hi for wave32

This doesn't seem to be needed for anything.

Differential Revision: https://reviews.llvm.org/D92400

[AMDGPU] Use pseudo instructions for readlane/writelane

This reverts r227987 "R600/SI: Determine target-specific encoding of READLANE and WRITELANE early v2".

All the codegen changes are caused by

[AMDGPU] Use pseudo instructions for readlane/writelane

This reverts r227987 "R600/SI: Determine target-specific encoding of READLANE and WRITELANE early v2".

All the codegen changes are caused by the post-RA scheduler no longer
treating readlane/writelane as scheduling barriers due to having
unmodelled side effects. (The pseudos are hasSideEffects = 0, but the
real instructions are hasSideEffects = ? which TableGen conservatively
treats as 1.)

Differential Revision: https://reviews.llvm.org/D90401

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Revert "[AMDGPU] Insert waitcnt after returning from call"

This reverts commit ca907bfb57d8ad3ec3bcc2cff2abab7b1b933af6.

According to michel.daenzer,
> This completely broke the Mesa radeonsi drive

Revert "[AMDGPU] Insert waitcnt after returning from call"

This reverts commit ca907bfb57d8ad3ec3bcc2cff2abab7b1b933af6.

According to michel.daenzer,
> This completely broke the Mesa radeonsi driver on Navi 14. Xorg +
> xterm come up with major corruption & psychedelic colours.

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[AMDGPU] Insert waitcnt after returning from call

When memory operations are outstanding on function calls, either the
caller or the callee can insert a waitcnt to ensure that all reads are
finished

[AMDGPU] Insert waitcnt after returning from call

When memory operations are outstanding on function calls, either the
caller or the callee can insert a waitcnt to ensure that all reads are
finished.
Calls need some time to be executed, so if the callee inserts the
waitcnt, filling the instruction buffer and waiting for memory will be
interleaved, hiding some latency. This comes at the cost of having a
waitcnt inside functions that may not be needed as no memory operations
are outstanding.

For function calls, this is already implemented. The same principal
applies to returns: If the caller inserts a waitcnt after the call, the
callee does not have to wait and the return and memory operation can be
run in parallel.

This commit implements waiting in the caller after returning from a
function call.

Differential Revision: https://reviews.llvm.org/D87674

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[AMDGPU] Fix offset for REL32_HI relocs

The addend in a REL32 reloc needs to be adjusted to account for the
offset from the PC value returned by the s_getpc instruction to the
point where the reloc

[AMDGPU] Fix offset for REL32_HI relocs

The addend in a REL32 reloc needs to be adjusted to account for the
offset from the PC value returned by the s_getpc instruction to the
point where the reloc is applied. This was being done correctly for
(GOTPC)REL32_LO but not for (GOTPC)REL32_HI. This will only make a
difference if the target symbol happens to get loaded almost exactly
a multiple of 4G away from the relocated instructions.

Differential Revision: https://reviews.llvm.org/D86938

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AMDGPU: Implement waterfall loop for MIMG instructions with 256-bit SRsrc

Summary:
When the resource descriptor is of vgpr, we need a waterfall loop
to read into a sgpr. In this patchm we generali

AMDGPU: Implement waterfall loop for MIMG instructions with 256-bit SRsrc

Summary:
When the resource descriptor is of vgpr, we need a waterfall loop
to read into a sgpr. In this patchm we generalized the implementation
to work for any regster class sizes, and extend the work to MIMG
instructions.

Fixes: SWDEV-223405

Reviewers:
arsenm, nhaehnle

Differential Revision:
https://reviews.llvm.org/D82603

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[AMDGPU] Update VMEM scalar write hazard mitigation sequence

Using s_waitcnt_depctr 0xffe3 is potentially faster than v_nop.

Reviewed By: rampitec, foad

Differential Revision: https://reviews.llvm

[AMDGPU] Update VMEM scalar write hazard mitigation sequence

Using s_waitcnt_depctr 0xffe3 is potentially faster than v_nop.

Reviewed By: rampitec, foad

Differential Revision: https://reviews.llvm.org/D83872

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[AMDGPU] More accurate gfx10 latencies

Differential Revision: https://reviews.llvm.org/D81012

[AMDGPU] New SIInsertHardClauses pass

Enable clausing of memory loads on gfx10 by adding a new pass to insert
the s_clause instructions that mark the start of each hard clause.

Differential Revisio

[AMDGPU] New SIInsertHardClauses pass

Enable clausing of memory loads on gfx10 by adding a new pass to insert
the s_clause instructions that mark the start of each hard clause.

Differential Revision: https://reviews.llvm.org/D79792

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[AMDGPU] Fixed the test by adding the triple.

[AMDGPU] Introduce more scratch registers in the ABI.

The AMDGPU target has a convention that defined all VGPRs
(execept the initial 32 argument registers) as callee-saved.
This convention is not ef

[AMDGPU] Introduce more scratch registers in the ABI.

The AMDGPU target has a convention that defined all VGPRs
(execept the initial 32 argument registers) as callee-saved.
This convention is not efficient always, esp. when the callee
requiring more registers, ended up emitting a large number of
spills, even though its caller requires only a few.

This patch revises the ABI by introducing more scratch registers
that a callee can freely use.
The 256 vgpr registers now become:
32 argument registers
112 scratch registers and
112 callee saved registers.
The scratch registers and the CSRs are intermixed at regular
intervals (a split boundary of 8) to obtain a better occupancy.

Reviewers: arsenm, t-tye, rampitec, b-sumner, mjbedy, tpr

Reviewed By: arsenm, t-tye

Differential Revision: https://reviews.llvm.org/D76356

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