Commit graph

357 commits

Author SHA1 Message Date
Ian Romanick
17e6f19044 glsl: Generate an interface type for uniform blocks
If the block has an instance name, add the instance name to the symbol
table instead of the individual fields.

Fixes the piglit test interface-name-access-without-interface-name.vert
for real.

v2: Update the comment before the assertion that interface block
definitions won't generate instructions.  Suggested by Paul Berry.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
2013-01-25 09:07:33 -05:00
Ian Romanick
491364e1f3 glsl: Add GLSL_TYPE_INTERFACE
Interfaces are structurally identical to structures from the compiler's
point of view.  They have some additional restrictions, and generally
GPUs use different instructions to access them.  Using a different base
type should make this a bit easier.

This commit also adds the glsl_type::interface_packing fields.  For
GLSL_TYPE_INTERFACE types, this will track the specified packing mode.
It is analogous to gl_uniform_buffer::_Packing.

v2: Add serveral missing GLSL_TYPE_INTERFACE cases in switch-statements.

v3: Add information about glsl_type::interface_packing.  Move row_major
checking in glsl_type::record_key_compare from this patch to the
previous patch.  Both suggested by Paul Berry.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2013-01-25 09:07:33 -05:00
Ian Romanick
51f740cd5a glsl: Refactor out processing of structure fields
This will soon also be used for processing interface block fields.

v2: Add a comment explaining the interface of
ast_process_structure_or_interface_block.  Suggested by Paul Berry.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Carl Worth <cworth@cworth.org>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
Reviewed-by: Chad Versace <chad.versace@linux.intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2013-01-25 09:07:33 -05:00
Ian Romanick
9a971ab695 mesa: Track the packing mode of a UBO in gl_uniform_buffer
This allows the next patch to verify that two uniform blocks match
without first calculating the locations of the fields.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Chad Versace <chad.versace@linux.intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2013-01-25 09:07:33 -05:00
Ian Romanick
ecfb404e8d glsl: Replace most default cases in switches on GLSL type
This makes it easier to find switch-statements that need to be updated
after a new GLSL_TYPE_* is added because the compiler will generate a
warning.

Switch-statements that only had a small number of cases (e.g.,
everything in ir_constant_expression.cpp) were not modified.  I may
regret that decision when we eventually add support for doubles.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Carl Worth <cworth@cworth.org>
Reviewed-by: Chad Versace <chad.versace@linux.intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2013-01-25 09:07:32 -05:00
Paul Berry
c6a50ddfcb glsl: Allow varying structs in GLSL ES 3.00 and GLSL 1.50.
Previously I thought that varying structs had been added to GLSL ES
3.00 by mistake, because chapter 11 of the GLSL ES 3.00 spec
("Counting of Inputs and Outputs") failed to mention how structs
should be handled.  Khronos has clarified
(https://cvs.khronos.org/bugzilla/show_bug.cgi?id=9828) that varying
structs are indeed required, and that chapter 11 will be modified to
indicate that the minimal reference packing algorithm flattens varying
structs to their individual components.

Mesa doesn't flatten varying structs to their individual components,
but this is ok, since it packs varyings of all kinds with no wasted
space at all (except where this is impossible due to differing
interpolation modes), so it will outperform the minimal reference
packing algorithm in all but the most pathological cases.

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
2013-01-24 16:30:49 -08:00
Paul Berry
42a29d89fd glsl: Eliminate ambiguity between function ins/outs and shader ins/outs
This patch replaces the three ir_variable_mode enums:

- ir_var_in
- ir_var_out
- ir_var_inout

with the following five:

- ir_var_shader_in
- ir_var_shader_out
- ir_var_function_in
- ir_var_function_out
- ir_var_function_inout

This eliminates a frustrating ambiguity: it used to be impossible to
tell whether an ir_var_{in,out} variable was a shader in/out or a
function in/out without seeing where the variable was declared in the
IR.  This complicated some optimization and lowering passes, and would
have become a problem for implementing varying structs.

In the lisp-style serialization of GLSL IR to strings performed by
ir_print_visitor.cpp and ir_reader.cpp, I've retained the names "in",
"out", and "inout" for function parameters, to avoid introducing code
churn to the src/glsl/builtins/ir/ directory.

Note: a couple of comments in the code seemed to indicate that we were
planning for a possible future in which geometry shaders could have
shader-scope inout variables.  Our GLSL grammar rejects shader-scope
inout variables, and I've been unable to find any evidence in the GLSL
standards documents (or extensions) that this will ever be allowed, so
I've eliminated these comments.

Reviewed-by: Carl Worth <cworth@cworth.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
2013-01-24 16:30:30 -08:00
Ian Romanick
56053b0a2d mesa: Remove unused field gl_uniform_buffer_variable::Buffer
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2013-01-18 17:35:33 -08:00
Kenneth Graunke
4f29169913 glsl: Track UBO block names in the symbol table.
The GLSL 1.40 spec says:

    "Uniform block names and variable names declared within uniform
    blocks are scoped at the program level."

Track the block name in the symbol table and emit errors when conflicts
exist.

Fixes es3conform's uniform_buffer_object_block_name_conflict test, and
fixes the piglit block-name-clashes-with-{variable,function,struct}.vert
tests.

NOTE: This is a candidate for the 9.0 branch.

v2: Fix bad constructor initialization.  Noticed by Topi Pohjolainen.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2013-01-18 17:35:32 -08:00
Ian Romanick
bb47a4d081 glsl: Reject row_major and column_major on non-matrix types
About both row_major and column_major layout qualifiers, the GLSL spec
says:

    "It only affects the layout of matrices."

However, the OpenGL ES 3.0 conformance tests have taken this to mean it
is an error use it elsewhere.  This seems logical given that
'layout(row_major) vec4 foo' is probably not what the programmer meant.

The only catch is dealing with structures that contain matrices.  Layout
qualifiers cannot be applied directly to fields of structures, so the
only way to affect the layout of the fields is to apply a qualifier to
the structure declaration itself.  There is ongoing debate about this
within Khronos, and it seems to be settling in favor of allowing the
qualifiers on structures.  I light of this, I have chosen to allow the
qualifiers on structures but emit a warning since the usage may not be
portable.

Fixes gles3conform test
uniform_buffer_object_layouts_not_for_matrix_type and causes no
regressions.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2013-01-18 17:35:32 -08:00
Paul Berry
18720555dd glsl: Prohibit structs and bools from being used as "varyings".
The GLSL 1.30 spec only allows vertex shader outputs and fragment
shader inputs ("varyings" in pre-GLSL-1.30 parlance) to be of type
int, uint, float, or vectors, matrices, or arrays thereof.  Bools,
bvec's, and structs are prohibited.  (Integral varyings were
prohibited prior to GLSL 1.30).

Previously, Mesa only performed this check on variables declared with
the "varying" keyword, and it always performed the check according to
the pre-GLSL-1.30 rules.  As a result, bools and structs were allowed
to slip through, provided they were declared using the new in/out
syntax.

This patch modifies the error check so that it occurs after "varying"
is converted to "in/out", and corrects it to properly account for GLSL
version.

Fixes piglit tests:
  in-bool-prohibited.frag
  in-bvec2-prohibited.frag
  in-bvec3-prohibited.frag
  in-bvec4-prohibited.frag
  in-struct-prohibited.frag
  out-bool-prohibited.vert
  out-bvec2-prohibited.vert
  out-bvec3-prohibited.vert
  out-bvec4-prohibited.vert
  out-struct-prohibited.vert

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2013-01-08 09:09:21 -08:00
Paul Berry
c33be485c5 glsl: Plumb through is_parameter to apply_type_qualifier_to_variable()
This patch adds logic to allow the ast_to_hir function
apply_type_qualifier_to_variable() to tell whether it is acting on a
variable declaration or a function parameter.  This will allow it to
correctly interpret the meaning of "out" and "in" keywords (which have
different meanings in those two contexts).

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2013-01-08 09:09:18 -08:00
Paul Berry
d4a24745b8 glsl: Enable GLSL ES 3.00 features inherited from desktop GLSL.
This patch turns on the following features for GLSL ES 3.00:

- Array constructors, whole array assignment, and array comparisons.
- Second and third operands of ?: may be arrays.
- Use of "in" and "out" qualifiers on globals.
- Bitwise and modulus operators.
- Integral vertex shader inputs.
- Range-checking of literal integers.
- array.length method.
- Function calls may be constant expressions.
- Integral varyings must be qualified with "flat".
- Interpolation and centroid qualifiers may not be applied to vertex
  shader inputs.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Carl Worth <cworth@cworth.org>
2012-12-06 12:13:21 -08:00
Paul Berry
0d9bba6e43 glsl: Make use of new _mesa_glsl_parse_state::check_version() function.
Previous to this patch, we were not very consistent about the errors
we generate when a shader tried to use a feature that is prohibited in
the current GLSL version.  Some error messages failed to mention the
GLSL version currently in use (or did so inaccurately), and some error
messages failed to mention the first GLSL version in which the given
feature is allowed.

This patch reworks all of the error checks to use the check_version()
function, which produces error messages in a standard form
(approximately "$FEATURE forbidden in $CURRENT_GLSL_VERSION
($REQUIRED_GLSL_VERSION required).").

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Carl Worth <cworth@cworth.org>
2012-12-06 12:13:21 -08:00
Paul Berry
e3ded7fe62 glsl: Make use of new _mesa_glsl_parse_state::is_version() function.
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Carl Worth <cworth@cworth.org>
2012-12-06 12:13:21 -08:00
Paul Berry
dc9f9d8e66 glsl: Compute version_string on the fly.
Fixes a bug where version_string would be left uninitialized if no
GLSL "#version" directive was used.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Carl Worth <cworth@cworth.org>
2012-12-06 12:13:21 -08:00
Paul Berry
53e572f15c glsl: Simplify symbol table version checking.
Previously, we stored the GLSL language version in the
glsl_symbol_table struct.  But this was unnecessary--all
glsl_symbol_table needs to know is whether functions and variables
have separate namespaces (they do in GLSL 1.10 only).

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Carl Worth <cworth@cworth.org>
2012-12-06 12:13:21 -08:00
Brian Paul
78d3cfb5b4 glsl: remove incorrect 'struct' keyword
ir_variable is a class, not a struct.  Fixes an MSVC warning.

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
2012-11-06 07:42:37 -07:00
Kenneth Graunke
354f2cb5c7 glsl: Generate compile errors for explicit blend indices < 0 or > 1.
According to the GLSL 4.30 specification, this is a compile time error.
Earlier specifications don't specify a behavior, but since 0 and 1 are
the only valid indices for dual source blending, it makes sense to
generate the error.

Fixes (the fixed version of) piglit's layout-12.frag.

NOTE: This is a candidate for the 9.0 branch.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
2012-09-10 20:56:11 -07:00
Eric Anholt
86e0045578 glsl: Only flag RowMajor on matrix-type variables.
We were only propagating it to the API when the variable was a matrix type,
but we were still tripping over it in lower_ubo_reference when it was set on a
vector.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2012-08-07 13:54:50 -07:00
Eric Anholt
b3c093c79c glsl: Translate the AST for uniform blocks into some IR structures.
We're going to need this structure to cross-validate the uniform
blocks between shader stages, since unused ir_variables might get
dropped.  It's also the place we store the RowMajor qualifier, which
is not part of the GLSL type (since that would cause a bunch of type
equality checks to fail).

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-07-20 10:43:19 -07:00
Eric Anholt
f7561e8ecd glsl: Turn UBO variable declarations into ir_variables and check qualifiers.
Fixes piglit layout-*-non-uniform and layout-*-within-block.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-07-20 10:43:12 -07:00
Kenneth Graunke
d43f4181e1 glsl: Remove open coded version of ir_variable::interpolation_string().
Presumably the function didn't exist when we wrote this code.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-07-19 11:00:00 -07:00
Eric Anholt
2d03f48a65 glsl: Add parsing for GLSL uniform blocks.
This doesn't do anything with the uniform block declarations yet, so
usage of those uniforms finds them to be undeclared.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-07-09 11:13:33 -07:00
Ian Romanick
adfe531841 glsl: Remove spurious printf messages
These look like debug messages from the switch-statement development.

NOTE: This is a candidate for the 8.0 release branch.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
2012-06-01 12:27:04 -07:00
Eric Anholt
aa5ec13775 glsl: Drop the extra NULL specifiction on ir_assignment constructors.
It's an implied argument, and I don't think being explicit about it
helps.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-05-17 10:05:24 -07:00
Eric Anholt
9c4e9ce051 glsl: Fix assertion failure on handling switch on uint expressions.
Fixes piglit glsl-1.30/execution/switch/fs-uint.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-05-17 10:05:24 -07:00
Eric Anholt
bbbc7c7d56 glsl: Reject non-scalar switch expressions.
The comment quotes spec saying that only scalar integers are allowed,
but we only checked for integer.

Fixes piglit switch-expression-const-ivec2.vert

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-05-17 10:05:24 -07:00
Eric Anholt
5d6ea16dfe glsl: Let the constructor figure out the types of switch-related expressions.
I noticed this while unindenting the code.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-05-17 10:05:24 -07:00
Eric Anholt
5462f3679a glsl: Fix indentation of switch code.
I managed to completely trash it in 22d81f15.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-05-17 10:05:23 -07:00
Eric Anholt
b2ee5a08ba glsl: Don't consider unused FS out variables as being statically assigned.
I only considered var->assigned for FragColor and FragData, but
ignored when it was false for out vars.  Fixes piglit
write-gl_FragColor-and-not-user-output.frag

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=49068
2012-05-04 14:00:32 -07:00
Eric Anholt
4b2a4cb7c2 glsl: Properly throw compile-time errors for conflicting FS output writes.
We were checking for these at link time previously, which is not as
early as mandated, and would actually fail to detect conflicting
writes if dead code removal removed some writes.

Fixes failures in piglit
glsl-*/compiler/fragment-outputs/write-gl_Frag*

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2012-04-19 16:33:45 -07:00
Eric Anholt
f2475ca424 glsl: Track in each ir_variable whether it was ever assigned.
This will be used for some compile-and-link-time error checking, where
currently we've been doing error checking only at link time.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2012-04-19 16:33:36 -07:00
Dave Airlie
1256a5dcc8 glsl: add support for ARB_blend_func_extended (v3)
This adds index support to the GLSL compiler.

I'm not 100% sure of my approach here, esp without how output ordering
happens wrt location, index pairs, in the "mark" function.

Since current hw doesn't ever have a location > 0 with an index > 0,
we don't have to work out if the output ordering the hw requires is
location, index, location, index or location, location, index, index.
But we have no hw to know, so punt on it for now.

v2: index requires layout - catch and error
    setup explicit index properly.

v3: drop idx_offset stuff, assume index follow location

Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-04-13 17:19:01 +01:00
Eric Anholt
eb7a71dea7 glsl: Drop the round-trip through ast_type_specifier for many builtin types.
We have lexer recognition of a bunch of our types based on the
handling.  This code was mapping those recognized tokens to an enum
and then to a string of their name.  Just drop the enums and provide
the string directly in the parser.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2012-04-09 14:30:46 -07:00
Kenneth Graunke
807e967c61 glsl: Use ir_rvalue to represent generic error_type values.
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>
2012-04-02 14:15:34 -07:00
Kenneth Graunke
dca19a7711 glsl: Explicitly NULL-check variables before making a dereference.
The constructor currently returns a ir_dereference_variable of error
type when provided NULL, but that's about to change in the next commit.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
2012-03-26 10:21:55 -07:00
Eric Anholt
ead3589aa2 glsl: Avoid extra if statements for logic and/or with no side effects.
This avoids extra if statements in the common case of just comparing
two expressions that don't involve assignments or function calls,
along with simplifying the handling of constant expressions.  Reduces
i965 instructions generated in unigine tropics and sanctuary,
yofrankie, warsow, gstreamer shaders, and the weston compositor.

shader-db results:
Total instructions: 213052 -> 212752
38/1246 programs affected (3.0%)
14309 -> 14009 instructions in affected programs (2.1% reduction)
2012-03-13 13:50:08 -07:00
Eric Anholt
57e44371a5 glsl: Add error case for switch() with two default cases.
Fixes piglit switch-case-duplicated.vert.

NOTE: This is a candidate for the 8.0 branch.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-02-03 11:07:04 +01:00
Eric Anholt
140632190c glsl: Throw an error when faced with a duplicated switch() case label.
The error message I chose matches gcc's error.  Fixes piglit
switch-case-duplicated.vert.

NOTE: This is a candidate for the 8.0 branch.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-02-03 11:07:02 +01:00
Eric Anholt
2c3e10e719 glsl: Throw the required error when a case label is a non-constant.
It's not quite spelled out in the spec text, but the grammar indicates
that only constant values are allowed as switch() case labels (and
only constant values make sense, anyway).

Fixes piglit glsl-1.30/compiler/switch-statement/switch-case-uniform-int.vert.

NOTE: This is a candidate for the 8.0 branch.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-02-03 11:06:54 +01:00
Eric Anholt
22d81f154f glsl: Save and restore the whole switch state for nesting.
This stuffs them all in a struct for sanity.  Fixes piglit
glsl-1.30/execution/switch/fs-uniform-nested.

NOTE: This is a candidate for the 8.0 branch.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-02-03 11:06:50 +01:00
Eric Anholt
916e206ef0 glsl: Add error checking for applying interpolation qualifiers to other vars.
Fixes piglit
glsl-1.30/compiler/interpolation-qualifiers/local-smooth-01.frag.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2012-01-10 16:44:16 -08:00
Ian Romanick
1f125374e7 glsl: Don't mark assignment temporaries as read-only
The various l-value errors this was designed to catch are now caught
by other means.  Marking the temporaries as read-only now just
prevents sensible error messages from being generated.  It's

0:0(0): error: function parameter 'out p' references the read-only variable '_post_incdec_tmp'

versus

0:13(5): error: function parameter 'out p' references a post-decrement operation

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
2012-01-06 14:32:50 -08:00
Ian Romanick
e9015e99d0 glsl: Emit errors for assignments to non-l-value expressions
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=42755
2012-01-06 14:32:50 -08:00
Ian Romanick
fa0a9ac5cd glsl: Track descriptions of some expressions that can't be l-values
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Paul Berry <stereotype441@gmail.com>
2012-01-06 14:32:50 -08:00
Ian Romanick
3946448951 glsl: Don't use base type for bit-not when there's an error
Other parts of the compiler assume that expressions will have
well-formed types or the error type.  Just using the type of the thing
being operated on can cause expressions like ~3.14 or ~false to not
have a well-formed type.  This could then result in an assertion
failure in the context epxression handler.

If there is an error processing the expression, set the type of the IR
expression to error.

Fixes piglit's bit-not-0[789].frag tests.

NOTE: This is a candidate for the 7.11 branch.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=42755
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Cc: Vinson Lee <vlee@vmware.com>
2012-01-04 12:43:10 -08:00
Marek Olšák
6b43d6fdda glsl: finish up ARB_conservative_depth (v2)
v2: updated an error message

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2011-11-22 20:56:50 +01:00
Dan McCabe
5c02e2e2de glsl: Generate IR for switch statements
Up until now modifying the GLSL compiler has been pretty straightforward.
This is where things get interesting. But still pretty straightforward.

Switch statements can be thought of a series of if/then/else statements.
Case labels are compared with the value of a test expression and the case
statements are executed if the comparison is true.

There are a couple of aspects of switch statements that complicate this simple
view of the world. The primary one is that cases can fall through sequentially
to subsequent case, unless a break statement is encountered, in which case,
the switch statement exits completely.

But break handling is further complicated by the fact that a break statement
can impact the exit of a loop. Thus, we need to coordinate break processing
between switch statements and loop statements.

The code generated by a switch statement maintains three temporary state
variables:
    int test_value;
    bool is_fallthru;
    bool is_break;

test_value is initialized to the value of the test expression at the head of
the switch statement. This is the value that case labels are compared against.

is_fallthru is used to sequentially fall through to subsequent cases and is
initialized to false. When a case label matches the test expression, this
state variable is set to true. It will also be forced to false if a break
statement has been encountered. This forcing to false on break MUST be
after every case test. In practice, we defer that forcing to immediately after
the last case comparison prior to executing a case statement, but that is
an optimization.

is_break is used to indicate that a break statement has been executed and is
initialized to false. When a break statement is encountered, it is set to true.
This state variable is then used to conditionally force is_fallthru to to false
to prevent subsequent case statements from executing.

Code generation for break statements depends on whether the break statement is
inside a switch statement or inside a loop statement. If it inside a loop
statement is inside a break statement, the same code as before gets generated.
But if a switch statement is inside a loop statement, code is emitted to set
the is_break state to true.

Just as ASTs for loop statements are managed in a stack-like
manner to handle nesting, we also add a bool to capture the innermost switch
or loop condition. Note that we still need to maintain a loop AST stack to
properly handle for-loop code generation on a continue statement. Technically,
we don't (yet) need a switch AST stack, but I am using one for orthogonality
with loop statements, in anticipation of future use. Note that a simple
boolean stack would have sufficed.

We will illustrate a switch statement with its analogous conditional code that
a switch statement corresponds to by examining an example.

Consider the following switch statement:
	switch (42) {
	case 0:
	case 1:
		gl_FragColor = vec4(1.0, 2.0, 3.0, 4.0);
	case 2:
	case 3:
		gl_FragColor = vec4(4.0, 3.0, 2.0, 1.0);
		break;
	case 4:
	default:
		gl_FragColor = vec4(0.0, 0.0, 0.0, 0.0);
	}

Note that case 0 and case 1 fall through to cases 2 and 3 if they occur.

Note that case 4 and the default case must be reached explicitly, since cases
2 and 3 break at the end of their case.

Finally, note that case 4 and the default case don't break but simply fall
through to the end of the switch.

For this code, the equivalent code can be expressed as:
	int test_val = 42; // capture value of test expression
	bool is_fallthru = false; // prevent initial fall through
	bool is_break = false; // capture the execution of a break stmt

	is_fallthru |= (test_val == 0); // enable fallthru on case 0
	is_fallthru |= (test_val == 1); // enable fallthru on case 1
	is_fallthru &= !is_break; // inhibit fallthru on previous break
	if (is_fallthru) {
		gl_FragColor = vec4(1.0, 2.0, 3.0, 4.0);
	}

	is_fallthru |= (test_val == 2); // enable fallthru on case 2
	is_fallthru |= (test_val == 3); // enable fallthru on case 3
	is_fallthru &= !is_break; // inhibit fallthru on previous break
	if (is_fallthru) {
		gl_FragColor = vec4(4.0, 3.0, 2.0, 1.0);
		is_break = true; // inhibit all subsequent fallthru for break
	}

	is_fallthru |= (test_val == 4); // enable fallthru on case 4
	is_fallthru = true; // enable fallthru for default case
	is_fallthru &= !is_break; // inhibit fallthru on previous break
	if (is_fallthru) {
		gl_FragColor = vec4(0.0, 0.0, 0.0, 0.0);
	}

The code generate for |= and &= uses the conditional assignment capabilities
of the IR.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2011-11-07 16:31:22 -08:00
Dan McCabe
85beb39e14 glsl: Reference data structure ctors in grammar
We now tie the grammar to the ctors of the ASTs they reference.

This requires that we actually have definitions of the ctors.

In addition, we also need to define "print" and "hir" methods for the AST
classes. The Print methods are pretty simple to flesh out. However, at this
stage of the development, we simply stub out the "hir" methods and flesh
them out later.

Also, since actual class instances get returned by the productions in the
grammar, we also need to designate the type of the productions that
reference those instances.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2011-11-07 16:31:22 -08:00