glsl: Try vectorizing when seeing a repeated assignment to a channel.

When considering assignment expressions like:

    v.x += u.x;
    v.x += u.x;

the vectorizer would incorrectly keep going, attempting to find more
instructions to vectorize.  It would overwrite the saved assignment
to point at the second one, and increment channels a second time,
resulting in try_vectorize thinking the expression was a vec2 instead of
a float.

Instead, if we see a repeated assignment to a channel, just try to
vectorize everything we've found so far.  This clears the saved state
so it will start over.

Fixes Piglit's repeated-channel-assignments.vert.

Cc: "10.1" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
draw: remove unused 'start' variable in draw_stats_clipper_primitives()

It was computed, but never actually used.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
docs: Fix ubo indexing description

Ian points out that this being unrestricted was an oversight in the
spec, and is corrected in GLSL4.40.

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
i965/gen7: Skip repeated NULL depth/stencil state emits.

Improves cairo performance on glamor by 2.87752% +/- 0.966977 (n=57).

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
i965: Skip a bunch of IB BO refcount twiddling.

Improves cairo performance on glamor by 1.64828% +/- 1.04742% (n=65).

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
i965: Stop setting up a 1:1 "attrib" member in our vertex inputs.

It's just the array index, so we can just go look at the array and see
which element we are.

No significant performance difference (n=140)

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
i965: Fill in a bunch of gen7/hsw data cache-related disasm.

This gets us disasm of atomic ops.

v2: Fix fallthrough on pre-gen7.  (bug caught by Ilia Mirkin).

Reviewed-by: Matt Turner <mattst88@gmail.com>
i965/fs: Reset reg_from when we can't coalesce.

Not setting this would prevented coalescing after a failed attempt if
the sources for both MOVs were the same.

total instructions in shared programs: 1654531 -> 1650224 (-0.26%)
instructions in affected programs:     423167 -> 418860 (-1.02%)
GAINED:                                2
LOST:                                  0

Reviewed-by: Eric Anholt <eric@anholt.net>
i965: Correct EmitNoIndirect shader compiler option flags.

These were out of sync with the flags used to control
lower_variable_index_to_cond_assign in brw_shader.cpp.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
i965: Use EmitNoIndirect flags in lower_variable_index_to_cond_assign.

This will prevent the two from getting out of sync again.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
glsl: Drop do_common_optimization's max_unroll_iterations parameter.

Now that we pass in gl_shader_compiler_options, it makes sense to just
use options->MaxUnrollIterations, rather than passing a separate
parameter.

Half of the invocations already passed options->MaxUnrollIterations,
while the other half passed in a hardcoded value of 32.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
glsl: Pass gl_shader_compiler_optimizations to unroll_loops().

Loop unrolling will need to know a few more options in the future.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
glsl: Rename loop_unroll_count::fail to "nested_loop."

The "fail" flag is set if loop_unroll_count encounters a nested loop;
calling the flag "nested_loop" is a bit clearer.

The original reasoning was that count is inaccurate (too small) if there
are nested loops, as we don't do any sort of analysis on the inner loop.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
glsl: Ignore loop-too-large heuristic if there's bad variable indexing.

Many shaders use a pattern such as:

for (int i = 0; i < NUM_LIGHTS; i++) {
   ...access a uniform array, or shader input/output array...
}

where NUM_LIGHTS is a small constant (such as 2, 4, or 8).

The expectation is that the compiler will unroll those loops, turning
the array access into constant indexing, which is more efficient, and
which may enable array splitting and other optimizations.

In many cases, our heuristic fails - either there's another tiny nested
loop inside, or the estimated number of instructions is just barely
beyond the threshold.  So, we fail to unroll the loop, leaving the
variable indexing in place.

Drivers which don't support the particular flavor of variable indexing
will call lower_variable_index_to_cond_assign(), which generates piles
and piles of immensely inefficient code.  We'd like to avoid generating
that.

This patch detects unsupported forms of variable-indexing in loops, where
the array index is a loop induction variable.  In that case, it bypasses
the loop-too-large heuristic and forces unrolling.

Improves performance in various microbenchmarks: Gl32PSBump8 by 47%,
Gl32ShMapVsm by 80%, and Gl32ShMapPcf by 27%.  No changes in shader-db.

v2: Check ir->array for being an array or matrix, rather than the
    ir_dereference_array itself.
v3: Fix and expand statistics in commit message.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
i965: Add comment to explain the weird-looking shadow compares.

This always looks crazy when I stumble across it, until I remember
what the hardware is doing. Describing it ought to short-circuit
that process next time :)

V2: Fix indents to 6 spaces, not 7.

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
i965: glClearBuffer() should only clear a single buffer.

glClearBuffer() is currently clearing all active draw color buffers (all
buffers that have not been set to GL_NONE when calling glDrawBuffers) instead
of only clearing the one it receives as parameter. Altough brw_clear()
receives a bit mask indicating the color buffers that should be cleared,
this mask is ignored when calling brw_blorp_clear_color().

This was breaking the 'fbo-drawbuffers-none glClearBuffer' piglit test.

The patch provides the bit mask to brw_blorp_clear_color() so it can limit
clearing to the color buffers present in the mask.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=76832
Reviewed-by: Eric Anholt <eric@anholt.net>
mesa: Fix typo in error message

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
egl-static: fix build after recent radeon winsys changes

Signed-off-by: Marek Olšák <marek.olsak@amd.com>
glsl: Fix typo in interface block comment

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
mesa: Extract is_active_attrib() in shaderapi

The rules are about to get a bit more complex to account for
gl_InstanceID and gl_VertexID, which are system values.

Extracting this first avoids introducing duplication.

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>