<feed xmlns='http://www.w3.org/2005/Atom'>
<title>slang.git/tests/cross-compile/matrix-mult.slang, branch master</title>
<subtitle>Making it easier to work with shaders</subtitle>
<id>https://git.yummers.dev/slang.git/atom?h=master</id>
<link rel='self' href='https://git.yummers.dev/slang.git/atom?h=master'/>
<link rel='alternate' type='text/html' href='https://git.yummers.dev/slang.git/'/>
<updated>2018-02-03T15:30:54+00:00</updated>
<entry>
<title>Remove non-IR codegen paths (#398)</title>
<updated>2018-02-03T15:30:54+00:00</updated>
<author>
<name>Tim Foley</name>
<email>tfoleyNV@users.noreply.github.com</email>
</author>
<published>2018-02-03T15:30:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.yummers.dev/slang.git/commit/?id=662f43fff6721c6cd013a8f1b2639c2e29fe6be3'/>
<id>urn:sha1:662f43fff6721c6cd013a8f1b2639c2e29fe6be3</id>
<content type='text'>
The basic change is simple: remove support for all code generation paths other than the IR.
There is a lot of vestigial code left, but the main logic in `ast-legalize.*` is gone.

Doing this breaks a *lot* of tests, for various reasons:

- We can no longer guarantee exactly matching DXBC or SPIR-V output after things pass through out IR

- Many builtins don't have matching versions defined for GLSL output via IR (even when they had versions defined via the earlier approach that worked with the AST)

- A lot of code creates intermediate values of opaque types in the IR, which turn into opaque-type temporaries that aren't allowed (this breaks many GLSL tests, but also some HLSL)

I implemented some small fixes for issues that I could get working in the time I had, but most of the above are larger than made sense to fix in this commit.

For now I'm disabling the tests that cause problems, but we will need to make a concerted effort to get things working on this new substrate if we are going to make good on our goals.</content>
</entry>
<entry>
<title>Fix output for matrix multiple in GLSL code (#228)</title>
<updated>2017-10-23T17:37:07+00:00</updated>
<author>
<name>Tim Foley</name>
<email>tfoleyNV@users.noreply.github.com</email>
</author>
<published>2017-10-23T17:37:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.yummers.dev/slang.git/commit/?id=ab64cf2ec05980d72cb2bad45e629d10ebbefdc1'/>
<id>urn:sha1:ab64cf2ec05980d72cb2bad45e629d10ebbefdc1</id>
<content type='text'>
When Slang sees a matrix multiplication `M * v` in GLSL code it should (obviously) output GLSL code that also does `M * v`, but there was a bug introduced where the type-checker manages to resolve the operation and recognize it as a matrix-vector multiply, and then the code-generation logic says "oh, I'm generating output for GLSL, and that is reversed from HLSL/Slang, so I'd better reverse these operands!" and outputs `v * M`... which isn't what we want.

I've fixed the problem in an expedient way, by having the front-end resolve the operation to what it believes is an intrinsic multiply operation, rather than a matrix-vector operation. If we ever support cross compilation *from* GLSL (unlikely), we've need to fix this up so that we have both real matrix-vector multiplies and "reversed" multiplies where the operands folow the GLSL convention).

I've added two tests here to confirm the fix. The one under `tests/bugs` catches the actual issue described above, and confirms the fix. The other one under `tests/cross-compile` is just to make sure that we *do* properly reverse the operands to a matrix-vector product when converting from Slang to GLSL.</content>
</entry>
</feed>
