diff options
| author | jsmall-nvidia <jsmall@nvidia.com> | 2020-02-04 15:19:48 -0500 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2020-02-04 15:19:48 -0500 |
| commit | 17c6c6044965629a3ae7e8ef004cc0b2ca657c55 (patch) | |
| tree | 5b78004808354b32d09ba13c0ec4e32a44f345ab /docs/64bit-type-support.md | |
| parent | b415760d7f166eaad7fa27daa09edc9a8964c37e (diff) | |
CUDA/C++ backend improvements (#1198)
* WIP with vector float test.
* vector-float test working.
* Fixed remaing tests broken with init changes.
* Improve 64bit-type-support.md
* Disable tests broken on CI system for Dx.
* WIP: Make type available for comparison.
* Moved type conversion into TypeTextUtil.
* Add text/type conversions from DownstreamCompiler to TypeTextUtil.
* Allow compaison taking into account type.
* Removed quantize in vector-float.slang test.
Diffstat (limited to 'docs/64bit-type-support.md')
| -rw-r--r-- | docs/64bit-type-support.md | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/docs/64bit-type-support.md b/docs/64bit-type-support.md index 7c345d4af..f934c97fe 100644 --- a/docs/64bit-type-support.md +++ b/docs/64bit-type-support.md @@ -1,6 +1,22 @@ Slang 64-bit Type Support ========================= +## Summary + +* Not all targets support 64 bit types, or all 64 bit types + * 64 bit integers generally require later APIs/shader models +* When specifying 64 bit literals *always* use the type suffixes (ie `l`, `ull`, `ll`) +* GPU target/s generally do not support all double intrinsics + * Typically missing are trascendentals (sin, cos etc), logarithm and exponental functions + * CUDA is the exception supporting nearly all double intrinsics +* D3D + * D3D targets *appear* to support double intrinsics (like sin, cos, log etc), but behind the scenes they are actually being converted to float + * When using D3D12, it is best to use DXIL if you use double because there are some serious issues around double and DXBC +* VK will produce an error in validation if a double intrinsic is used it does support (which is most of them) + +Overview +======== + The Slang language supports 64 bit built in types. Such as * double @@ -58,8 +74,8 @@ CPU | | Yes | Yes | 1 CUDA | Nvrtx/PTX | Yes | Yes | 1 D3D12 | DXC/DXIL | Yes | Small Subset | 4 Vulkan | GlSlang/Spir-V | Yes | Partial | 2 -D3D11 | FXC/DXBC | Yes | No | 4 -D3D12 | FXC/DXBC | Yes | No | 3, 4 +D3D11 | FXC/DXBC | Yes | Small Subset | 4 +D3D12 | FXC/DXBC | Yes | Small Subset | 3, 4 1) CUDA and CPU support most intrinsics, with the notable exception currently of matrix invert 2) In terms of lack of general intrinsic support, the restriction is described in https://www.khronos.org/registry/spir-v/specs/1.0/GLSL.std.450.html |