[all-commits] [llvm/llvm-project] 05093e: [Spirv][HLSL] Add OpAll lowering and float vec sup...

[Farzon Lotfi via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 05093e243859a371f96ffa1c320a4b51579c3da7
      https://github.com/llvm/llvm-project/commit/05093e243859a371f96ffa1c320a4b51579c3da7
  Author: Farzon Lotfi <1802579+farzonl at users.noreply.github.com>
  Date:   2024-04-10 (Wed, 10 Apr 2024)

  Changed paths:
    M llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.cpp
    M llvm/lib/Target/SPIRV/SPIRVGlobalRegistry.h
    M llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp
    A llvm/test/CodeGen/SPIRV/hlsl-intrinsics/all.ll

  Log Message:
  -----------
  [Spirv][HLSL] Add OpAll lowering and float vec support (#87952)

The main point of this change was to add support for HLSL's all
intrinsic.
In the process of doing that I found a few issues around creating an
`OpConstantComposite` via `buildZerosVal`.

First the current code didn't support floats so the process of adding
`buildZerosValF` meant I needed a
float version of `getOrCreateIntConstVector`. After doing so I renamed
both versions to `getOrCreateConstVector`. That meant I needed to create
a float type version of `getOrCreateIntCompositeOrNull`. Luckily the
type information was low for this function so was able to split it out
into a helpwe and rename `getOrCreateIntCompositeOrNull` to
`getOrCreateCompositeOrNull` With the exception of type handling
differences of the code and Null vs 0 Constant Op codes these functions
should be identical.

To handle scalar floats I could not use `buildConstantFP` like this PR
did:
https://github.com/llvm/llvm-project/commit/0a2aaab5aba46#diff-733a189c5a8c3211f3a04fd6e719952a3fa231eadd8a7f11e6ecf1e584d57411R1603
because that would create too many superfluous registers (that causes
problems in the validator), I had to create a float version of
`getOrCreateConstInt` which I called `getOrCreateConstFP`.
similar problems with doing it like this:
https://github.com/llvm/llvm-project/blob/main/llvm/lib/Target/SPIRV/SPIRVBuiltins.cpp#L1540.

`buildZerosValF` also has a use of a function `getZeroFP`. This is
because half, float, and double scalar values of 0 would collide in
`SPIRVDuplicatesTracker<Constant> CT` if you use `APFloat(0.0f)`.

`getORCreateConstFP` needed its own version of `getOrCreateConstIntReg`
which I called `getOrCreateConstFloatReg` The one difference in this
function is `getOrCreateConstFloatReg` returns a bit width so we don't
have to call `getScalarOrVectorBitWidth` twice ie when it is used again
in `getOrCreateConstFP` for `OpConstantF` `addNumImm`.

`getOrCreateConstFloatReg` needed an `assignFloatTypeToVReg` helper
which called a `getOrCreateSPIRVFloatType` helper. There was no
equivalent IntegerType::get for floats so I handled this with a switch
statement on bit widths to get the right LLVM float type.

Finally, there is the use of `bool ZeroAsNull = STI.isOpenCLEnv();` This
is partly a cosmetic change. When Zeros are treated as nulls, we don't
create `OpConstantComposite` vectors which is something we do in the
DXCs SPIRV backend. The DXC SPIRV backend also does not use
`OpConstantNull`. Finally, I needed a means to test the behavior of the
OpConstantNull and `OpConstantComposite` changes and this was one way I
could do that via the same tests.



To unsubscribe from these emails, change your notification settings at https://github.com/llvm/llvm-project/settings/notifications