sysgpu: implement select() intrinsic for HLSL, MSL, and SPIR-V #1436

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Crispigt wants to merge 2 commits from Crispigt/sysgpu/hlsl-select into main

Crispigt commented

2025-11-24 10:54:42 +00:00

(Migrated from github.com)

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This PR implements the select() intrinsic for HLSL, MSL, and SPIR-V. It also fixes a missing boolean implementation in MSL.

Fixes a panic when compiling shaders using WGSL select().

HLSL: Mapped to the ternary operator (cond ? true : false).
MSL: Mapped to metal::select(false, true, cond).
- Fix: Implemented emitBool for MSL (was previously commented out and not implemented), required for select conditions using literals.
SPIR-V: Emits OpSelect (OpCode 69).

Left GLSL unimplemented for now as the test suite appears commented out in test.zig, so I figured I wouldn't implement it.

Tested Verified output generation locally for HLSL, MSL, and SPIR-V using a simple test case.
Validated runtime behavior for HLSL and SPIR-V, by rendering a checkered triangle (using select in the fragment shader) on Windows 11 with an AMD Radeon RX 7900 XTX.

- [x] By selecting this checkbox, I agree to license my contributions to this project under the license(s) described in the LICENSE file, and I have the right to do so or have received permission to do so by an employer or client I am producing work for whom has this right. This PR implements the `select()` intrinsic for HLSL, MSL, and SPIR-V. It also fixes a missing boolean implementation in MSL. Fixes a panic when compiling shaders using WGSL `select()`. * HLSL: Mapped to the ternary operator `(cond ? true : false)`. * MSL: Mapped to `metal::select(false, true, cond)`. * Fix: Implemented `emitBool` for MSL (was previously commented out and not implemented), required for `select` conditions using literals. * SPIR-V: Emits `OpSelect` (OpCode 69). Left GLSL unimplemented for now as the test suite appears commented out in `test.zig`, so I figured I wouldn't implement it. Tested Verified output generation locally for HLSL, MSL, and SPIR-V using a simple test case. Validated runtime behavior for HLSL and SPIR-V, by rendering a checkered triangle (using `select` in the fragment shader) on Windows 11 with an AMD Radeon RX 7900 XTX.

This pull request is broken due to missing fork information.

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Checkout

From your project repository, check out a new branch and test the changes.

git fetch -u origin Crispigt/sysgpu/hlsl-select:Crispigt/sysgpu/hlsl-select

git switch Crispigt/sysgpu/hlsl-select

Merge

Merge the changes and update on Forgejo.

Warning: The "Autodetect manual merge" setting is not enabled for this repository, you will have to mark this pull request as manually merged afterwards.

git switch main

git merge --no-ff Crispigt/sysgpu/hlsl-select

git switch Crispigt/sysgpu/hlsl-select

git rebase main

git switch main

git merge --ff-only Crispigt/sysgpu/hlsl-select

git switch Crispigt/sysgpu/hlsl-select

git rebase main

git switch main

git merge --no-ff Crispigt/sysgpu/hlsl-select

git switch main

git merge --squash Crispigt/sysgpu/hlsl-select