<feed xmlns='http://www.w3.org/2005/Atom'>
<title>slang.git/source/slang/compiler.h, 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>2019-05-31T21:20:37+00:00</updated>
<entry>
<title>Use slang- prefix on slang compiler and core source (#973)</title>
<updated>2019-05-31T21:20:37+00:00</updated>
<author>
<name>jsmall-nvidia</name>
<email>jsmall@nvidia.com</email>
</author>
<published>2019-05-31T21:20:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.yummers.dev/slang.git/commit/?id=6cbc3929a54d37bd23cb5efa8e3320ba02f78b2f'/>
<id>urn:sha1:6cbc3929a54d37bd23cb5efa8e3320ba02f78b2f</id>
<content type='text'>
* Prefixing source files in source/slang with slang-

* Prefix source in source/slang with slang- prefix.

* Rename core source files with slang- prefix.

* Update project files.

* Fix problems from automatic merge.
</content>
</entry>
<entry>
<title>WIP: Support for other source target language (#971)</title>
<updated>2019-05-31T17:17:34+00:00</updated>
<author>
<name>jsmall-nvidia</name>
<email>jsmall@nvidia.com</email>
</author>
<published>2019-05-31T17:17:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.yummers.dev/slang.git/commit/?id=b81ff3ef968d1cc4e954b31a1812b3c391d17b02'/>
<id>urn:sha1:b81ff3ef968d1cc4e954b31a1812b3c391d17b02</id>
<content type='text'>
* WIP: Setting up C/Cpp source compilation targets.

* WIP: Emitting C/CPP.

* WIP: Split out SourceSink, and use it for source output on emit.

* SourceSink -&gt; SourceStream

* * Made SourceStream use m_ prefixing of members.
* Make all methods use lower camel
* Removed methods from SourceStream interface that are not used externally (use _ prefixing)
* Improvements to documentation

* EmitContext is now effectively empty, so just use SharedEmitContext as EmitContext.

* SharedEmitContext -&gt; EmitContext

* Methods to LowerCamel in emit.cpp

* Split out EmitContext and ExtensionUsageTracker into separate files.

* Split out EmitVisitor into slang-c-like-source-emitter files.

* EmitVisitor -&gt; CLikeSourceEmitter

* Tidy up around CLikeSourceEmitter - simplify header.

* Small tidy up - removing repeated comments that are in header.

* Remove EmitContext paramter threading.

* Small tidy up.
Use prefixed macros for slang-c-like-source-emitter.h

* Small tidy up in slang-c-like-source-emitter.cpp

* First pass at splitting out UnmangleContext.

* MangledNameParser -&gt; MangledLexer.

* WIP making EmitOp (EOp) enum available outside of cpp

* Generating EmitOpInfo from macro.

* Split out emit precedence handling.
Don't use kOp_ style anymore, just use an array indexed by EmitOp.

* Disable C simple test for now.

* Keep g++/clang happy with token pasting.

* Fix win32 narrowing warning.
</content>
</entry>
<entry>
<title>Changes required for application adoption of interface-type parameters (#963)</title>
<updated>2019-05-20T17:40:38+00:00</updated>
<author>
<name>Tim Foley</name>
<email>tfoleyNV@users.noreply.github.com</email>
</author>
<published>2019-05-20T17:40:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.yummers.dev/slang.git/commit/?id=71e35b6822b9e2846e129a888774d45a5e0827da'/>
<id>urn:sha1:71e35b6822b9e2846e129a888774d45a5e0827da</id>
<content type='text'>
* A few changes required for application adoption of interface-type parameters

There are a few small changes here that are all related in that they arose from trying to integrate support for specialization via global interface-type shader parameters into a real application.

Allow querying the "pending" layout via reflection API
------------------------------------------------------

The naming here isn't ideal, and could probably use a round of "bikeshedding" to arrive at something better, but the basic idea is that when you have a type like:

```
struct MyStuff
{
    int a;
    IFoo foo;
    int b;
}
```

the fields `a` and `b` get allocated space directly in the "primary" layout for `MyStuff` (at offsets 0 and 4, with `sizeof(MyStuff) == 8`), but the `foo` field can't be allocated space until we know what concrete type will get plugged in there.

If we have a concrete type in mind:

```
struct Bar : IFoo { int bar; }
```

then we can know how much space the `foo` field will take up, but we still can't allocate it space directly in `MyStuff`, because we already decided that `sizeof(MyStuff) == 8`.

Now imagine we place some `MyStuff` values into constant buffers:

```
cbuffer X {
    MyStuff x;
}

cbuffer Y {
    MyStuff y;
    float4 z;
}
```

In each case we know that we want to place the `MyStuff::foo` field at the end of the containing constant buffer so that it doesn't disrupt the layout of the existing fields. But that means that the offset of `MyStuff::foo` relative to the start of the `MyStuff` isn't fixed, because of unrelated fields like `z` that need to get in between.

In our layout code, we handle this by having a notion of a "pending" layout. Once we know how `MyStuff::foo` will be specialized, we can compute both a "primary" and a "pending" layout for `MyStuff`, which basically treats it as if it were two distinct types:

```
struct MyStuff_Primary
{
    int a;
    int b;
}

struct MyStuff_Pending
{
    Bar foo;
}
```

Layout for an aggregate type like the `X` or `Y` constant buffer then proceeds by computing an aggregate primary layout and an aggregate pending layout, and then finally a constant buffer or parameter block "flushes" all or part of the pending data by appending it to the primary data to get the final layout.

What all this means is that a type like `MyStuff` will have two different layouts (a default one for the primary data and a "pending" one for any specialized interface-type fields), and a variable like `Y::y` will also have two variable layouts that specify offsets (one set of offsets for its primary part, and one set of offsets for its pending part).

In order to handle interface-type fields with these layout rules, an application needs a way to query the "pending" part of a type or variable layout, which luckily gives it back just another type/variable layout. The API change here is minimal, although actually exploiting the new API correctly in application code could prove challenging.

Allow creating of explicitly specialized types
----------------------------------------------

This feature isn't actually implemented all the way through the compiler (I just needed enough to make the API calls go through), but I've added support for specializing a type that has interface-type fields through the reflection API. This maps to an `ExistentialSpecializedType` in the AST, and I'm lowering it to the IR as a `BindExistentialsType`, although that isn't 100% correct for the future.

This feature will require a future PR to actually flesh out the implementation work, but I'll wait until that is the sticking point on the application side before I do that.

Introduce a tiny `Hasher` abstraction
-------------------------------------

While implementing all the boilerplate for a new `Type` subclass (we really need to reduce that work...), I got fed up with how we do hash-code computation and introduced a small utility `Hasher` type that is intended to wrap up the idiom of combining hashes. For now this isn't a major change, but in the future I'd like to expand on the design a bit to clean up some of the warts around how we handle hashing:

* The `Hasher` implementation can and should switch from maintaining a single `HashCode` as its state to something that contains a more complete state (larger than the hash code) and just hashes new bytes into that state as it goes. This should make it possible to implement a `Hasher` for more serious hash functions, whether MD5, CityHash, or whatever we decide is good default.

* Things that are hashable shouldn't have a `getHashCode()` method, but instead should have something like a `hashInto(Hasher&amp;)` method. This change would have the dual benefits that (1) a composite type can easily hash all the fields that contribute to its identity into the hasher with minimal fuss/boilerplate, and (2) the hashes for composite types will be of higher quality because they can exploit all the bits of the hasher's state to combine the fields, instead of restricting each sub-field to just the bits in a hash code.

We should be able to incrementally improve the quality of our design there over future changes, but for now it probably isn't a critical priority.

Fixes for legalization of existential types
-------------------------------------------

There were some missing cases in the handling of type legalization, such that a global interface-type shader parameter that got specialized to a type that contains *only* resource-type fields would cause a crash in the legalization step.

I added a test for this case, and then made `ir-legalize-types.cpp` account for this case (the code to handle it ias a bit of a kludge, and shows that the `declareVars()` routine there is getting to a level of complexity that is worrying.

* fixup: review feedback
</content>
</entry>
<entry>
<title>String/List closer to conventions, and use Index type (#959)</title>
<updated>2019-04-29T21:03:46+00:00</updated>
<author>
<name>jsmall-nvidia</name>
<email>jsmall@nvidia.com</email>
</author>
<published>2019-04-29T21:03:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.yummers.dev/slang.git/commit/?id=4880789e3003441732cca4471091563f36531635'/>
<id>urn:sha1:4880789e3003441732cca4471091563f36531635</id>
<content type='text'>
* List made members m_
Tweaked types to closer match conventions.

* Use asserts for checking conditions on List.
Other small improvements.

* List&lt;T&gt;.Count() -&gt; getSize()

* List&lt;T&gt;
Add -&gt; add
First -&gt; getFirst
Last -&gt; getLast
RemoveLast -&gt; removeLast
ReleaseBuffer -&gt; detachBuffer
GetArrayView -&gt; getArrayView

* List&lt;T&gt;::
AddRange -&gt; addRange
Capacity -&gt; getCapacity
Insert -&gt; insert
InsertRange -&gt; insertRange
AddRange -&gt; addRange
RemoveRange -&gt; removeRange
RemoveAt -&gt; removeAt
Remove -&gt; remove
Reverse -&gt; reverse
FastRemove -&gt; fastRemove
FastRemoveAt -&gt; fastRemoveAt
Clear -&gt; clear

* List&lt;T&gt;
FreeBuffer -&gt; _deallocateBuffer
Free -&gt; clearAndDeallocate
SwapWith -&gt; swapWith

* List&lt;T&gt;
SetSize -&gt; setSize
Reserve -&gt; reserve
GrowToSize growToSize

* UnsafeShrinkToSize -&gt; unsafeShrinkToSize
Compress -&gt; compress
FindLast -&gt; findLastIndex
FindLast -&gt; findLastIndex
Simplify Contains

* List&lt;T&gt;
Removed m_allocator (wasn't used)
Swap -&gt; swapElements
Sort -&gt; sort
Contains -&gt; contains
ForEach -&gt; forEach
QuickSort -&gt; quickSort
InsertionSort -&gt; insertionSort
BinarySearch -&gt; binarySearch

Max -&gt; calcMax
Min -&gt; calcMin

* Initializer::Initialize -&gt; initialize
List&lt;T&gt;::
Allocate -&gt; _allocate
Init -&gt; _init
IndexOf -&gt; indexOf

* * Put #include &lt;assert.h&gt; in common.h, and remove unneeded inclusions
* Small refactor of ArrayView - remove stride as not used

* getSize -&gt; getCount
setSize -&gt; setCount
unsafeShrinkToSize-&gt;unsafeShrinkToCount
growToSize -&gt; growToCount
m_size -&gt; m_count

* Some tidy up around Allocator.

* Use Index type on List.

* Refactor of IntSet.
First tentative look at using Index.

* Made Index an Int
Did preliminary fixes.
Made String use Index.

* Partial refactor of String.

* String::Buffer -&gt; getBuffer
ToWString -&gt; toWString

* Small improvements to String.
String::
Buffer() -&gt; getBuffer()
Equals() -&gt; equals

* Try to use Index where appropriate.

* Fix warnings on windows x86 builds.
</content>
</entry>
<entry>
<title>Add better control over image formats for GLSL/SPIR-V targets (#939)</title>
<updated>2019-04-08T18:09:03+00:00</updated>
<author>
<name>Tim Foley</name>
<email>tfoleyNV@users.noreply.github.com</email>
</author>
<published>2019-04-08T18:09:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.yummers.dev/slang.git/commit/?id=dc54f1dd1b694b087816857a791e9d37dc25de6d'/>
<id>urn:sha1:dc54f1dd1b694b087816857a791e9d37dc25de6d</id>
<content type='text'>
* Add better control over image formats for GLSL/SPIR-V targets

Currently Slang emits GLSL code assuming all R/W images need to have explicit formats, and thus we try to infer a format from the element type of the image.
E.g., given a `RWTexture2D&lt;half4&gt;` we might infer that a qualifier of `layout(rgba16f)` should be used.

This strategy has two notable shortcomings:

* Sometimes the user will want a format that doesn't match an existing HLSL type. E.g., if they want the equivalent of `layout(r11f_g11f_b10f)`, then what should they put in their `RWTexture2D&lt;...&gt;` to make the inference do what they need?

* Sometimes the user knows that they don't need to specify a format *at all*, because using the `GL_EXT_shader_image_load_formatted` extension, they can still perform non-atomic load/store on images with no format specified in the SPIR-V.

This change adds two features directed at these challenges.

First, we add an explicit `[format(...)]` attribute that can be used to specify an explicit image format, including ones that don't match any HLSL type.
An example of using this new attribute is:

```hlsl
[format("r11f_g11f_b10f")]
RWTexture2D&lt;float3&gt; myImage;
```

For simplicity in initial bring-up, the new formats all use the same naming as formats in GLSL (this should make it easy for a programmer who knows what they expect to get in the GLSL output). We can change the naming convention for formats at a later time, so long as we keep these existing names in as a compatibility feature.

Note that this is *not* given a `vk::` prefix since the attribute should signal the programmer's intent to provide an image with that format on *all* targets (although only some targets might act on that information).

Also note that the attribute takes a string (`[format("rgba8")`) instead of a bare identifier (`[format(rgba8)]`) because this is consistent with the existing convention for attributes in HLSL.

When `[format(...)]` is left off, the default compiler behavior will still be to infer a format, but this behavior can be overidden for a single image using an explicit format of `"unknown"`:

```hlsl
[format("unknown")]
RWTexture2D&lt;float4&gt; mysteryMachine;
```

The second new feature is that if a user knows they are coding for a GPU that supports the `"unknown"` format in all non-atomic cases, then they can opt into making that the default for images without an explicit `[format(...)]`, using the new `-default-image-format-unknown` command-line option for `slangc`.

The new test case included with this change confirms that we correctly see the explicit formats in the output GLSL and *no* formats for images without explicit `[format(...)]` when using the new command-line option. The test stresses images declared at global scope, in parameter blocks, and in entry-point parameter lists, to try and make sure that all the relevant IR passes in the compiler preserve the format information.

* fixup: missing file
</content>
</entry>
<entry>
<title>Add options to control optimization and debug information (#897)</title>
<updated>2019-03-12T19:24:03+00:00</updated>
<author>
<name>Tim Foley</name>
<email>tfoleyNV@users.noreply.github.com</email>
</author>
<published>2019-03-12T19:24:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.yummers.dev/slang.git/commit/?id=3cfccfd4991df01deaf132f11b4eaa6848a32c4e'/>
<id>urn:sha1:3cfccfd4991df01deaf132f11b4eaa6848a32c4e</id>
<content type='text'>
The short version for command-line users is:

* Use `-g` to get debug info in the output, where supported
* Use `-O0` to disable optimizations, in case that improves debugability
* Use `-O2` for optimized/release builds where you can spend the extra compile time

The command-line options are matched with new API functions `spSetDebugInfoLevel()` and `spSetOptimizationLevel()` that set the equivalent information.

Right now these settings only affect how we invoke fxc and dxc. In the longer run I expect we will want to use them to control other things:

* Once we are emitting our own SPIR-V, the `-g` option should control what source-level name information we include in it.

* Whether or not `-g` is used could be used to decide whether we preserve the "name hints" in the IR, which in  turn decide whether we output GLSL/HLSL source that uses names based on the original program.

* We will eventually need/want to include some amount of optimization passes on the Slang IR, and the `-O` options should control which of those passes are enabled on a particular invocation.

In this change I decided to expose the options at the level of the entire compile request for API users, and to store the actual information on the Linkage. We might want to revisit this decision and instead allow for the level of optimization to be chosen per-target as part of back-end state. Similarly, we might want to have more fine-grained control over the level of debug output per-target (although we'd still need a front-end setting to determine what debug info is generated into the Slang IR).</content>
</entry>
<entry>
<title>Improve support for interfaces as shader parameters (#886)</title>
<updated>2019-03-09T00:24:02+00:00</updated>
<author>
<name>Tim Foley</name>
<email>tfoleyNV@users.noreply.github.com</email>
</author>
<published>2019-03-09T00:24:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.yummers.dev/slang.git/commit/?id=4f94dd46a2d885e570814dd14a5e46f8e0814802'/>
<id>urn:sha1:4f94dd46a2d885e570814dd14a5e46f8e0814802</id>
<content type='text'>
* Improve support for interfaces as shader parameters

This change adds two main things over the existing support:

1. It is now possible to plug in concrete types that actually contain (uniform/ordinary) fields for the existential type parameters introduced by interface-type shader parameters. The `interface-shader-param2.slang` test shows that this works.

2. There is a limited amount of support for doing correct layout computation and generating output code that matches that layout, so that interface and ordinary-type fields can be interleaved to a limited extent. The `interface-shader-param3.slang` test confirms this behavior.

There are several moving pieces in the change.

* When it comes to terminology, we try to draw a more clear distinction between existial type parameters/arguments and existential/object value parametes/arguments. A simple way to look at it is that an `IFoo[3]` shader parameter introduces a single existential type parameter (so that a concrete type argument like `SomeThing` can be plugged in for the `IFoo`) but introduces three existential object/value parameters (to represent the concrete values for the array elements).

* At the IR level, we support a few new operations. A `BindExistentialsType` can take a type that is not itself an interface/existential type but which depends on interfaces/existentials (e.g., `ConstantBuffer&lt;IFoo&gt;`) and plug in the concrete types to be used for its existential type slots.

* Then a `wrapExistentials` instruction can take a type with all the existentials plugged in (possibly by `BindExistentialsType`) and wrap it into a value of the existential-using type (e.g., turn `ConstantBuffer&lt;SomeThing&gt;` into a `ConstantBuffer&lt;IFoo&gt;`).

* The IR passes for doing generic/existential specialization have been updated to be able to desugar uses of these new operations just enough so that a `ConstantBuffer&lt;IFoo&gt;` can be used.

* When we specialize an IR parameter of an interface type like `IFoo` based on a concrete type `SomeThing`, we turn the parameter into an `ExistentialBox&lt;SomeThing&gt;` to reflect the fact that we are conceptually referring to `SomeThing` indirectly (it shouldn't be factored into the layout of its surrounding type).

* Parameter binding was updated so that it passes along the bound existential type arguments in a `Program` or `EntryPoint` to type layout, so that we can take them into account. The type layout code needs to do a little work to pass the appropriate range of arguments along to sub-fields when computing layout for aggregate types.

* Type layout was updated to have a notion of "pending" items, which represent the concrete types of data that are logically being referenced by existential value slots. The basic idea is that these values aren't included in the layout of a type by default, but then they get "flushed" to come after all the non-existential-related data in a constant buffer, parameter block, etc.

* The logic for computing a parameter group (`ConstantBuffer` or `ParameterBlock`) layout was updated to always "flush" the pending items on the element type of the group, so that the resource usage of specialized existential slots would be taken into account.

* The type legalization pass has been adapted so that we can derive two different passes from it. One does resource-type legalization (which is all that the original pass did). The new pass uses the same basic machinery to legalize `ExistentialBox&lt;T&gt;` types by moving them out of their containing type(s), and then turning them into ordinary variables/parameters of type `T`.

Big things missing from this change include:

- Nothing is making sure that "pending" items at the global or entry-point level will get proper registers/bindings allocated to them. For the uniform case, all that matters in the current compiler is that we declare them in the right order in the output HLSL/GLSL, but for resources to be supported we will need to compute this layout information and start associating it with the existential/interface-type fields.

- Nothing is being done to support `BindExistentials&lt;S, ...&gt;` where `S` is a `struct` type that might have existential-type fields (or nested fields...). Eventually we need to desugar a type like this into a fresh `struct` type that has the same field keys as `S`, but with fields replaced by suitable `BindExistentials` as needed. (The hard part of this would seem to be computing which slots go to which fields). As a practial matter, this missing feature means that interface-type members of `cbuffer` declarations won't work.

The current tests carefully avoid both of these problems. They don't declare any buffer/texture fields in the concrete types, and they don't make use of `cbuffer` declarations or `ConstantBuffer`s over structure types with interface-type fields.

* fixup: add override to methods

* fixup: typos
</content>
</entry>
<entry>
<title>Properly initialize m_modulesBeingImported otherwize it will segfault (#888)</title>
<updated>2019-03-08T14:51:14+00:00</updated>
<author>
<name>Toby Chen</name>
<email>chenyanjun912@hotmail.com</email>
</author>
<published>2019-03-08T14:51:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.yummers.dev/slang.git/commit/?id=74a340506bde3c668b05ad5aa1192cfa89763243'/>
<id>urn:sha1:74a340506bde3c668b05ad5aa1192cfa89763243</id>
<content type='text'>
</content>
</entry>
<entry>
<title>#include not using search paths (#873)</title>
<updated>2019-03-02T13:22:38+00:00</updated>
<author>
<name>jsmall-nvidia</name>
<email>jsmall@nvidia.com</email>
</author>
<published>2019-03-02T13:22:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.yummers.dev/slang.git/commit/?id=69d2651056137eb7c6e542491ae5fd59af095022'/>
<id>urn:sha1:69d2651056137eb7c6e542491ae5fd59af095022</id>
<content type='text'>
* Fix warnings from visual studio due to coercion losing data.

* Removed searchDirectories from FrontEndCompileRequest and use the one in Linkage as that is the one that is changed via Slang API.

* * Add searchPaths back to FrontEndRequest
* Add comments to explain the issue
* Add a test to check include paths
</content>
</entry>
<entry>
<title>Move enumeration of shader parameters to Program/EntryPoint (#870)</title>
<updated>2019-03-01T17:43:47+00:00</updated>
<author>
<name>Tim Foley</name>
<email>tfoleyNV@users.noreply.github.com</email>
</author>
<published>2019-03-01T17:43:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.yummers.dev/slang.git/commit/?id=620af1c60a2e84bbbc0e74f11cb9bc6a6976d9e4'/>
<id>urn:sha1:620af1c60a2e84bbbc0e74f11cb9bc6a6976d9e4</id>
<content type='text'>
There's a certain amount of logic in `parameter-binding.cpp` that just has to do with the basic problem of enumerating the shader parameters of a `Program`. The main source of complexity is that for legacy/compatibility reasons we need to consider two shader parameters with the same name as being the "same" parameter for layout purposes, and then we need to do a bunch of validation to ensure that these parameters have compatible types.

The biggest part of this change is moving that logic to `Program`, so that it builds up a list of its shader parameters during the front-end work, so that any errors related to bad redeclarations will now come up even if we aren't generated target-specific layouts/code.

All of the code for `getReflectionName`, `StructuralTypeMatchStack`, etc. is pretty much copy-pasted from `parameter-binding.cpp` over to `check.cpp`, with the `ParameterBindingContext` replaced with a `DiagnosticSink`.

The `Program::_collectShaderParameters` function (renamed from `_collectExistentialParams`) then deals with the enumeration and deduplication logic that used to happen in `collectGlobalScopeParameters()`.

The new declarations in `compiler.h` reveal the underlying reason for this change: by letting `Program` and `EntryPoint` handle the canonical enumeration of parameters, we can associate each parameter with the range of existential type slots it uses, which will simplify certain work around interfaces (not in this change...).

Moving the code out of parameter binding and into `check.cpp` revealed some unused GLSL-related code that I removed while I was at it.

I also found that the `IsDeclaration` case of `VarLayoutFlag` wasn't actually being used, so I went ahead and removed it (we can easily re-add it if we ever find a need for it).

Overall this isn't a big cleanup (mostly just code moving, rather than being eliminated), but it will facilitate other changes, and it seems cleaner overall to do this work once in target-independent logic, rather than per-target.</content>
</entry>
</feed>
