When translating a call from AST to HIR, we need to decide whether it
can be evaluated to a constant before emitting any code (namely, the
temporary declaration, assignment, and call.)
Soon, ir_call will become a statement taking a dereference of where to
store the return value, rather than an rvalue to be used on the RHS of
an assignment. It will be more convenient to try evaluation before
creating a call. ir_function_signature seems like a reasonable place.
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Currently, ir_call can be used as either a statement (for void
functions) or a value (for non-void functions). This is rather awkward,
as it's the only class that can be used in both forms.
A number of places use ir_call::get_error_instruction() to construct a
generic value of error_type. If ir_call is to become a statement, it
can no longer serve this purpose.
Unfortunately, none of our classes are particularly well suited for
this, and creating a new one would be rather aggrandizing. So, this
patch introduces ir_rvalue::error_value(), a static method that creates
an instance of the base class, ir_rvalue. This has the nice property
that you can't accidentally try and access uninitialized fields (as it
doesn't have any). The downside is that the base class is no longer
abstract.
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
When matching function signatures across multiple linked shaders, we
often want to see if the current shader has _any_ match, but also know
whether or not it was exact. (If not, we may want to keep looking.)
This could be done via the existing mechanisms:
sig = f->exact_matching_signature(params);
if (sig != NULL) {
exact = true;
} else {
sig = f->matching_signature(params);
exact = false;
}
However, this requires walking the list of function signatures twice,
which also means walking each signature's formal parameter lists twice.
This could be rather expensive.
Since matching_signature already internally knows whether a match was
exact or not, we can just return it to get that information for free.
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
This requires tracking a couple extra fields in ir_variable:
* A flag to indicate that a variable had an initializer.
* For non-const variables, a field to track the constant value of the
variable's initializer.
For variables non-constant initalizers, ir_variable::has_initializer
will be true, but ir_variable::constant_initializer will be NULL. The
linker can use the values of these fields to check adherence to the
GLSL 4.20 rules for shared global variables:
"If a shared global has multiple initializers, the initializers
must all be constant expressions, and they must all have the same
value. Otherwise, a link error will result. (A shared global
having only one initializer does not require that initializer to
be a constant expression.)"
Previous to 4.20 the GLSL spec simply said that initializers must have
the same value. In this case of non-constant initializers, this was
impossible to determine. As a result, no vendor actually implemented
that behavior. The 4.20 behavior matches the behavior of NVIDIA's
shipping implementations.
NOTE: This is candidate for the 7.11 branch. This patch also needs
the preceding patch "glsl: Refactor generate_ARB_draw_buffers_variables
to use add_builtin_constant"
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=34687
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Paul Berry <stereotype441@gmail.com>
This function determines how a variable should be interpolated based
both on interpolation qualifiers and the current shade model.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Previously, we treated the 'smooth' qualifier as equivalent to no
qualifier at all. However, this is incorrect for the built-in color
variables (gl_FrontColor, gl_BackColor, gl_FrontSecondaryColor, and
gl_BackSecondaryColor). For those variables, if there is no qualifier
at all, interpolation should be flat if the shade model is GL_FLAT,
and smooth if the shade model is GL_SMOOTH.
To make this possible, I added a new value to the
glsl_interp_qualifier enum, INTERP_QUALIFIER_NONE.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
This patch makes GLSL interpolation qualifiers visible to drivers via
the array InterpQualifier[] in gl_fragment_program, so that they can
easily be used by driver back-ends to select the correct interpolation
mode.
Previous to this patch, the GLSL compiler was using the enum
ir_variable_interpolation to represent interpolation types. Rather
than make a duplicate enum in core mesa to represent the same thing, I
moved the enum into mtypes.h and renamed it to be more consistent with
the other enums defined there.
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
The array_lvalue field was attempting to enforce the restriction that
whole arrays can't be used on the left-hand side of an assignment in
GLSL 1.10 or GLSL ES, and can't be used as out or inout parameters in
GLSL 1.10.
However, it was buggy (it didn't work properly for built-in arrays),
and it was clumsy (it unnecessarily kept track on a
variable-by-variable basis, and it didn't cover the GLSL ES case).
This patch removes the array_lvalue field completely in favor of
explicit checks in ast_parameter_declarator::hir() (this check is
added) and in do_assignment (this check was already present).
This causes a benign behavioral change: when the user attempts to pass
an array as an out or inout parameter of a function in GLSL 1.10, the
error is now flagged at the time the function definition is
encountered, rather than at the time of invocation. Previously we
allowed such functions to be defined, and only flagged the error if
they were invoked.
Fixes Piglit tests
spec/glsl-1.10/compiler/qualifiers/fn-{out,inout}-array-prohibited*
and
spec/glsl-1.20/compiler/assignment-operators/assign-builtin-array-allowed.vert.
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
It's the same as GL_AMD_conservative_depth. The specs have slight
differences in wording, but don't differ in content or behavior.
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
These functions don't modify the target instruction, so it makes sense
to make them const. This allows these functions to be called from ir
validation code (which uses const to ensure that it doesn't
accidentally modify the IR being validated).
Reviewed-by: Chad Versace <chad@chad-versace.us>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
The GLSL 1.20 and later specs say:
"Recursion is not allowed, not even statically. Static recursion is
present if the static function call graph of the program contains
cycles."
Recursion is detected and rejected both a compile-time and at
link-time. The complie-time check happens to detect some cases that
may be removed by various optimization passes. The spec doesn't seem
to allow this, but other vendors (e.g., NVIDIA) appear to only check
at link-time after all optimizations.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=33885
Reviewed-by: Paul Berry <stereotype441@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
The GLSL spec says:
"If a built-in function is redeclared in a shader (i.e., a
prototype is visible) before a call to it, then the linker will
only attempt to resolve that call within the set of shaders that
are linked with it."
This patch enforces this behavior. When a function call is processed
a flag is set in the ir_call to indicate whether the previously seen
prototype is the built-in or not. At link time a call will only bind
to an instance of a function that matches the "want built-in" setting
in the ir_call.
This has the odd side effect that first call to abs() in the shader
below will call the built-in and the second will not:
float foo(float x) { return abs(x); }
float abs(float x) { return -x; }
float bar(float x) { return abs(x); }
This seems insane, but it matches what the spec says.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=31744
These are necessary to handle int/uint constructor conversions. For
example, the following code currently results in a type mismatch:
int x = 7;
uint y = uint(x);
In particular, uint(x) still has type int.
This commit simply adds the new operations; it does not generate them,
nor does it add backend support for them.
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
We almost never want to specify a condition, and when we do we're
already thinking about it (because we're writing a lowering pass
generating the condition), so a default argument should make the code
more pleasant to read.
NOTE: This is a candidate for the 7.11 branch (we want to be able to
cherry-pick future code).
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
This should be the last bit of infrastructure changes before
generating GLSL IR for assembly shaders.
This commit leaves some odd code formatting in ir_to_mesa and brw_fs.
This was done to minimize whitespace changes / reindentation in some
loops. The following commit will restore formatting sanity.
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Chad Versace <chad.versace@intel.com>
This is necessary for GLSL 1.30+ shadow sampling functions, which return
a single float rather than splatting the value to a vec4 based on
GL_DEPTH_TEXTURE_MODE.
This annotation is for an "in" function parameter for which it is only legal
to pass constant expressions. The only known example of this, currently,
is the textureOffset functions.
This should never be used for globals.
Having these as actual integer values makes it difficult to implement
the texture*Offset built-in functions, since the offset is actually a
function parameter (which doesn't have a constant value).
The original rationale was that some hardware needs these offset baked
into the instruction opcode. However, at least i965 should be able to
support non-constant offsets. Others should be able to rely on inlining
and constant propagation.
In particular, variables cannot be redeclared invariant after being
used.
Fixes piglit test invariant-05.vert and bugzilla #29164.
NOTE: This is a candidate for the 7.9 and 7.10 branches.
I think was used long ago, when we actually read the builtins into the
shader's instruction stream directly, rather than creating a separate
shader and linking the two. It doesn't seem to serve any purpose now.
This doesn't cover all expressions or all operand types, but it will
complain if you overreach and it allows for much greater slack on the
programmer's part.
Hardware pretty commonly has saturate modifiers on instructions, and
this can be used in codegen to produce those, without everyone else
needing to understand clamping other than min and max.
The vector operator collects 2, 3, or 4 scalar components into a
vector. Doing this has several advantages. First, it will make
ud-chain tracking for components of vectors much easier. Second, a
later optimization pass could collect scalars into vectors to allow
generation of SWZ instructions (or similar as operands to other
instructions on R200 and i915). It also enables an easy way to
generate IR for SWZ instructions in the ARB_vertex_program assembler.
The operate just like ir_unop_sin and ir_unop_cos except that they
expect their inputs to be limited to the range [-pi, pi]. Several
GPUs require this limited range for their sine and cosine
instructions, so having these as operations (along with a to-be-written
lowering pass) helps this architectures.
These new operations also matche the semantics of the
GL_ARB_fragment_program SCS instruction. Having these as operations
helps in generating GLSL IR directly from assembly fragment programs.
This adds sentinel values to the ir_expression_operation enum type:
ir_last_unop, ir_last_binop, and ir_last_opcode. They are set to the
previous one so they don't trigger "unhandled case in switch statement"
warnings, but should never be handled directly.
This allows us to remove the huge array of 1s and 2s in
ir_expression::get_num_operands().
It turns out that most people new to this IR are surprised when an
assignment to (say) 3 components on the LHS takes 4 components on the
RHS. It also makes for quite strange IR output:
(assign (constant bool (1)) (x) (var_ref color) (swiz x (var_ref v) ))
(assign (constant bool (1)) (y) (var_ref color) (swiz yy (var_ref v) ))
(assign (constant bool (1)) (z) (var_ref color) (swiz zzz (var_ref v) ))
But even worse, even we get it wrong, as shown by this line of our
current step(float, vec4):
(assign (constant bool (1)) (w)
(var_ref t)
(expression float b2f (expression bool >=
(swiz w (var_ref x))(var_ref edge))))
where we try to assign a float to the writemasked-out x channel and
don't supply anything for the actual w channel we're writing. Drivers
right now just get lucky since ir_to_mesa spams the float value across
all the source channels of a vec4.
Instead, the RHS will now have a number of components equal to the
number of components actually being written. Hopefully this confuses
everyone less, and it also makes codegen for a scalar target simpler.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Currently GLSL IR forbids any vector comparisons, and defines "ir_binop_equal"
and "ir_binop_nequal" to compare all elements and give a single bool.
This is highly unintuitive and prevents generation of optimal Mesa IR.
Hence, first rename "ir_binop_equal" to "ir_binop_all_equal" and
"ir_binop_nequal" to "ir_binop_any_nequal".
Second, readd "ir_binop_equal" and "ir_binop_nequal" with the same semantics
as less, lequal, etc.
Third, allow all comparisons to acts on vectors.
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
