This PR adds support for default function parameters in the following cases:
1. Simple constants, such as void fn(int x, float myparam = 3)
2. Expressions that can be const folded, such a ... myparam = sin(some_const)
3. Initializer lists that can be const folded, such as ... float2 myparam = {1,2}
New tests are added: hlsl.params.default.frag and hlsl.params.default.err.frag
(for testing error situations, such as ambiguity or non-const-foldable).
In order to avoid sampler method ambiguity, the hlsl better() lambda now
considers sampler matches. Previously, all sampler types looked identical
since only the basic type of EbtSampler was considered.
HLSL allows type keywords to also be identifiers, so a sequence such as "float half = 3" is
valid, or more bizzarely, something like "float.float = int.uint + bool;"
There are places this is not supported. E.g, it's permitted for struct members, but not struct
names or functions. Also, vector or matrix types such as "float3" are not permitted as
identifiers.
This PR adds that support, as well as support for the "half" type. In production shaders,
this was seen with variables named "half". The PR attempts to support this without breaking
useful grammar errors such as "; expected" at the end of unterminated statements, so it errs
on that side at the possible expense of failing to accept valid constructs containing a type
keyword identifier. If others are discovered, they can be added.
Also, half is now accepted as a valid type, alongside the min*float types.
This commit adds support for copying nested hierarchical types of split
types. E.g, a struct of a struct containing both user and builtin interstage
IO variables.
When copying split types, if any subtree does NOT contain builtin interstage
IO, we can copy the whole subtree with one assignment, which saves a bunch
of AST verbosity for memberwise copies of that subtree.
This adds structure splitting, which among other things will enable GS support where input structs
are passed, and thus become input arrays of structs in the GS inputs. That is a common GS case.
The salient points of this PR are:
* Structure splitting has been changed from "always between stages" to "only into the VS and out of
the PS". It had previously happened between stages because it's not legal to pass a struct
containing a builtin IO variable.
* Structs passed between stages are now split into a struct containing ONLY user types, and a
collection of loose builtin IO variables, if any. The user-part is passed as a normal struct
between stages, which is valid SPIR-V now that the builtin IO is removed.
* Internal to the shader, a sanitized struct (with IO qualifiers removed) is used, so that e.g,
functions can work unmodified.
* If a builtin IO such as Position occurs in an arrayed struct, for example as an input to a GS,
the array reference is moved to the split-off loose variable, which is given the array dimension
itself.
When passing things around inside the shader, such as over a function call, the the original type
is used in a sanitized form that removes the builtIn qualifications and makes them temporaries.
This means internal function calls do not have to change. However, the type when returned from
the shader will be member-wise copied from the internal sanitized one to the external type.
The sanitized type is used in variable declarations.
When copying split types and unsplit, if a sub-struct contains only user variables, it is copied
as a single entity to avoid more AST verbosity.
Above strategy arrived at with talks with @johnkslang.
This is a big complex change. I'm inclined to leave it as a WIP until it can get some exposure to
real world cases.
Implement token pasting as per the C++ specification, within the current
style of the PP code.
Non-identifiers (turning 12 ## 10 into the numeral 1210) is not yet covered;
they should be a simple incremental change built on this one.
Addresses issue #255.
Unlike other qualifiers, HLSL allows "sample" to be either a qualifier keyword or an
identifier (e.g, a variable or function name).
A fix to allow this was made a while ago, but that fix was insufficient when 'sample'
was used in an expression. The problem was around the initial ambiguity between:
sample float a; // "sample" is part of a fully specified type
and
sample.xyz; // sample is a keyword in a dot expression
Both start the same. The "sample" was being accepted as a qualifier before enough
further parsing was done to determine we were not a declaration after all. This
consumed the token, causing it to fail for its real purpose.
Now, when accepting a fully specified type, the token is pushed back onto the stack if
the thing is not a fully specified type. This leaves it available for subsequent
purposes.
Changed the "hlsl.identifier.sample.frag" test to exercise this situation, distilled
down from a production shaders.
If some DCE is performed such as removing dead functions, then even
if we are NOT stripping debug info, we still must remove the debug
opcodes that refer to the now-dead IDs.
Also, this adds a small change to perform no ID remapping if none
is requested, making spirv-remap properly be a no-op if no options
are given.
This wasn't needed until the recent generalization of "main" to "entry point",
so makes some HLSL-specific code be generic now, for GLSL functional correctness.
This PR implements recursive type flattening. For example, an array of structs of other structs
can be flattened to individual member variables at the shader interface.
This is sufficient for many purposes, e.g, uniforms containing opaque types, but is not sufficient
for geometry shader arrayed inputs. That will be handled separately with structure splitting,
which is not implemented by this PR. In the meantime, that case is detected and triggers an error.
The recursive flattening extends the following three aspects of single-level flattening:
- Flattening of structures to individual members with names such as "foo[0].samp[1]";
- Turning constant references to the nested composite type into a reference to a particular
flattened member.
- Shadow copies between arrays of flattened members and the nested composite type.
Previous single-level flattening only flattened at the shader interface, and that is unchanged by this PR.
Internally, shadow copies are, such as if the type is passed to a function.
Also, the reasons for flattening are unchanged. Uniforms containing opaque types, and interface struct
types are flattened. (The latter will change with structure splitting).
One existing test changes: hlsl.structin.vert, which did in fact contain a nested composite type to be
flattened.
Two new tests are added: hlsl.structarray.flatten.frag, and hlsl.structarray.flatten.geom (currently
issues an error until type splitting is online).
The process of arriving at the individual member from chained postfix expressions is more complex than
it was with one level. See large-ish comment above HlslParseContext::flatten() for details.
PR #577 addresses most but not all of the intrinsic promotion problems.
This PR resolves all known cases in the remainder.
Interlocked ops need special promotion rules because at the time
of function selection, the first argument has not been converted
to a buffer object. It's just an int or uint, but you don't want
to convert THAT argument, because that implies converting the
buffer object itself. Rather, you can convert other arguments,
but want to stay in the same "family" of functions. E.g, if
the first interlocked arg is a uint, use only the uint family,
never the int family, you can convert the other args as you please.
This PR allows making such opcode and arg specific choices by
passing the op and arg to the convertible lambda. The code in
the new test "hlsl.promote.atomic.frag" would not compile without
this change, but it must compile.
Also, it provides better handling of downconversions (to "worse"
types), which are permitted in HLSL. The existing method of
selecting upconversions is unchanged, but if that doesn't find
any valid ones, then it will allow downconversions. In effect
this always uses an upconversion if there is one.
Recently added entry point renaming file referred to
test source file hlsl.entry.rename.frag via relative directory.
Change it to be consistent with other tests: assume test
sources are in the current directory.
Use "--source-entrypoint name" on the command line, or the
TShader::setSourceEntryPoint(char*) API.
When the name given to the above interfaces is detected in the
shader source, it will be renamed to the entry point name supplied
to the -e option or the TShader::setEntryPoint() method.
This PR handles implicit promotions for intrinsics when there is no exact match,
such as for example clamp(int, bool, float). In this case the int and bool will
be promoted to a float, and the clamp(float, float, float) form used.
These promotions can be mixed with shape conversions, e.g, clamp(int, bool2, float2).
Output conversions are handled either via the existing addOutputArgumentConversion
function, which this PR generalizes to handle either aggregates or unaries, or by
intrinsic decomposition. If there are methods or intrinsics to be decomposed,
then decomposition is responsible for any output conversions, which turns out to
happen automatically in all current cases. This can be revisited once inout
conversions are in place.
Some cases of actual ambiguity were fixed in several tests, e.g, spv.register.autoassign.*
Some intrinsics with only uint versions were expanded to signed ints natively, where the
underlying AST and SPIR-V supports that. E.g, countbits. This avoids extraneous
conversion nodes.
A new function promoteAggregate is added, and used by findFunction. This is essentially
a generalization of the "promote 1st or 2nd arg" algorithm in promoteBinary.
The actual selection proceeds in three steps, as described in the comments in
hlslParseContext::findFunction:
1. Attempt an exact match. If found, use it.
2. If not, obtain the operator from step 1, and promote arguments.
3. Re-select the intrinsic overload from the results of step 2.
HLSL has keywords for various interpolation modifiers such as "linear",
"centroid", "sample", etc. Of these, "sample" appears to be special,
as it is also accepted as an identifier string, where the others are not.
This PR adds this ability, so the construct "int sample = 42;" no longer
produces a compilation error.
New test = hlsl.identifier.sample.frag
