Otherwise, we'll often end up with gl_TexCoord being 0 length, for
example. With ir_to_mesa, things ended up working out anyway, as long
as multiple implicitly-sized arrays weren't involved.
It's trying to get an int smeared across all channels, not trying to
get a 1:1 mapping of a subset of a vector's channels. This usually
ended up not mattering with ir_to_mesa, since it just smears floats
into every chan of a vec4.
Fixes:
glsl1-temp array with swizzled variable indexing
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>
When ir_binop_all_equal and ir_binop_any_nequal were introduced, the
meaning of these two opcodes changed to return vectors rather than a
single scalar, but the constant expression handling code was incorrectly
written and only worked for scalars. As a result, only the first
component of the returned vector would be properly initialized.
Those have the callee field set to the null pointer, so
calling the public constructor will segfault.
Signed-off-by: Tilman Sauerbeck <tilman@code-monkey.de>
Fixes this GCC warning.
lower_variable_index_to_cond_assign.cpp:
In member function
'bool variable_index_to_cond_assign_visitor::needs_lowering(ir_dereference_array*) const':
lower_variable_index_to_cond_assign.cpp:261:
warning: control reaches end of non-void function
Currenly GLSL happily generates indirect addressing of any kind of
arrays.
Unfortunately DirectX 9 GPUs are not guaranteed to support any of them in
general.
This pass fixes that by lowering such constructs to a binary search on the
values, followed at the end by vectorized generation of equality masks, and
4 conditional assignments for each mask generation.
Note that this requires the ir_binop_equal change so that we can emit SEQ
to generate the boolean masks.
Unfortunately, ir_structure_splitting is too dumb to turn the resulting
constant array references to individual variables, so this will need to
be added too before this pass can actually be effective for temps.
Several patches in the glsl2-lower-variable-indexing were squashed
into this commit. These patches fix bugs in Luca's original
implementation, and the individual patches can be seen in that branch.
This was done to aid bisecting in the future.
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Fix the following GCC warning.
loop_controls.cpp: In function 'int calculate_iterations(ir_rvalue*, ir_rvalue*, ir_rvalue*, ir_expression_operation)':
loop_controls.cpp:88: warning: format not a string literal and no format arguments
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>
If the loop ends with an if with one break or in a single break unroll
it. Loops that end with a continue will have that continue removed by
the redundant jump optimizer. Likewise loops that end with an
if-statement with a break at the end of both branches will have the
break pulled out after the if-statement.
Loops of the form
for (...) {
do_something1();
if (cond) {
do_something2();
break;
} else {
do_something3();
}
}
will be unrolled as
do_something1();
if (cond) {
do_something2();
} else {
do_something3();
do_something1();
if (cond) {
do_something2();
} else {
do_something3();
/* Repeat inserting iterations here.*/
}
}
ir_lower_jumps can guarantee that all loops are put in this form
and thus all loops are now potentially unrollable if an upper bound
on the number of iterations can be found.
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
The loop_controls pass didn't look at the counter values it put in ir_loop
on previous iterations, so while the first iteration worked, subsequent
ones couldn't determine max_iterations.
Changes in v2:
- Base class renamed to ir_control_flow_visitor
- Tried to comply with coding style
This is a new pass that supersedes ir_if_return and "lowers" jumps
to if/else structures.
Currently it causes no regressions on softpipe and nv40, but I'm not sure
whether the piglit glsl tests are thorough enough, so consider this
experimental.
It can be asked to:
1. Pull jumps out of ifs where possible
2. Remove all "continue"s, replacing them with an "execute flag"
3. Replace all "break" with a single conditional one at the end of the loop
4. Replace all "return"s with a single return at the end of the function,
for the main function and/or other functions
This gives several great benefits:
1. All functions can be inlined after this pass
2. nv40 and other pre-DX10 chips without "continue" can be supported
3. nv30 and other pre-DX10 chips with no control flow at all are better supported
Note that for full effect we should also teach the unroller to unroll
loops with a fixed maximum number of iterations but with the canonical
conditional "break" that this pass will insert if asked to.
Continues are lowered by adding a per-loop "execute flag", initialized to
TRUE, that when cleared inhibits all execution until the end of the loop.
Breaks are lowered to continues, plus setting a "break flag" that is checked
at the end of the loop, and trigger the unique "break".
Returns are lowered to breaks/continues, plus adding a "return flag" that
causes loops to break again out of their enclosing loops until all the
loops are exited: then the "execute flag" logic will ignore everything
until the end of the function.
Note that "continue" and "return" can also be implemented by adding
a dummy loop and using break.
However, this is bad for hardware with limited nesting depth, and
prevents further optimization, and thus is not currently performed.
This is just a subclass of ir_visitor with empty implementations of all
the visit methods for non-control flow nodes.
Used to avoid duplicating that in ir_visitor subclasses.
ir_hierarchical_visitor is another way to solve this, but is less natural
for some applications.
This increases the chance that GLSL programs will actually work.
Note that continues and returns are not yet lowered, so linking
will just fail if not supported.
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Otherwise builtin_profiles contains dangling pointers the next time
_mesa_read_profile is called. I suspect this may fix bugzilla #29847,
but I was never able to reproduce it.
