glsl: Initialize ast_aggregate_initializer::constructor_type.

Fixes "Uninitialized pointer field" defect reported by Coverity.

Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
r600g/sb: Initialize ra_constraint::cost.

Fixes "Uninitialized scalar field" reported by Coverity.

Signed-off-by: Vinson Lee <vlee@freedesktop.org>
configure.ac: better detection of LLVM version

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>
gallivm: better support for fast rsqrt

We had to disable fast rsqrt before because it wasn't precise enough etc.
However in situations when we know we're not going to need more precision
we can still use a fast rsqrt (which can be several times faster than
the quite expensive sqrt). Hence introduce a new helper which does exactly
that - it is probably not useful calling it in some situations if there's
no fast rsqrt available so make it queryable if it's available too.

v2: use fast_rsqrt consistently instead of rsqrt_fast, fix indentation,
let rsqrt use fast_rsqrt.

Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
gallivm: handle srgb-to-linear and linear-to-srgb conversions

srgb-to-linear is using 3rd degree polynomial for now which should be _just_
good enough. Reverse is using some rational polynomials and is quite accurate,
though not hooked into llvmpipe's blend code yet and hence unused (untested).
Using a table might also be an option (for srgb-to-linear especially).
This does not enable any new features yet because EXT_texture_srgb was already
supported via util_format fallbacks, but performance was lacking probably due
to the external function call (the table used by the util_format_srgb code may
not be all that much slower on its own).
Some performance figures (taken from modified gloss, replaced both base and
sphere texture to use GL_SRGB instead of GL_RGB, measured on 1Ghz Sandy Bridge,
the numbers aren't terribly accurate):

normal gloss, aos, 8-wide: 47 fps
normal gloss, aos, 4-wide: 48 fps

normal gloss, forced to soa, 8-wide: 48 fps
normal gloss, forced to soa, 4-wide: 47 fps

patched gloss, old code, soa, 8-wide: 21 fps
patched gloss, old code, soa, 4-wide: 24 fps

patched gloss, new code, soa, 8-wide: 41 fps
patched gloss, new code, soa, 4-wide: 38 fps

So there's a performance hit but it seems acceptable, certainly better
than using the fallback.
Note the new code only works for 4x8bit srgb formats, others (L8/L8A8) will
continue to use the old util_format fallback, because I can't be bothered
to write code for formats noone uses anyway (as decoding is done as part of
lp_build_unpack_rgba_soa which can only handle block type width of 32).
Compressed srgb formats should get their own path though eventually (it is
going to be expensive in any case, first decompress, then convert).
No piglit regressions.

v2: use lp_build_polynomial instead of ad-hoc polynomial construction, also
since keeping both linear to srgb functions for now make sure both are
compiled (since they share quite some code just integrate into the same
function).

v3: formatting fixes and bugfix in the complicated (disabled) linear-to-srgb
path.

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
ilo: skip 3DSTATE_INDEX_BUFFER when possible

When only the offset to the index buffer is changed, we can skip the
3DSTATE_INDEX_BUFFER if we always use 0 for the offset, and add
(offset / index_size) to Start Vertex Location in 3DPRIMITIVE.
gallivm: (trivial) use constant instead of exp2f() function

Some lame compilers can't do exp2f() and as far as I can tell they can't do
exp2() (with doubles) neither so instead of providing some workaround for
that (wouldn't actually be too bad just replace with pow) and since it is
used with a constant only just use the precalculated constant.
i965/vs: Gen4/5: enable front colors if back colors are written

Fixes undefined results if a back color is written, but the
corresponding front color is not, and only backfacing primitives are
drawn. Results are still undefined if a frontfacing primitive is drawn,
but that's OK.

The other reasonable way to fix this would have been to just pick
the one color slot that was populated, but that dilutes the value of
the tests.

On Gen6+, the fixed function clipper and triangle setup already take
care of this.

Fixes 11 piglits:
spec/glsl-1.10/execution/interpolation/interpolation-none-gl_Back*Color-*

NOTE: This is a candidate for stable branches.

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
i965: Gen4/5: use IEEE floating point mode for GLSL shaders.

Fixes isinf(), isnan() from GLSL 1.30

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
glsl: Fix lower_named_interface_blocks to account for dereferences of consts.

In certain rare cases (such as those involving dereference of a
literal constant array of structs),
flatten_named_interface_blocks_declarations's rvalue visitor may be
invoked on an ir_dereference_record whose variable_referenced() method
returns NULL.

Check for this case to avoid a segfault.

Prevents crashes in piglit tests
{vs,fs}-deref-literal-array-of-structs.
glsl: Don't allow vertex shader input arrays until GLSL 1.50.

Vertex shader inputs are not allowed to be arrays until GLSL 1.50.  We
were accidentally enabling them for GLSL 1.40 (although we haven't
written any tests for them, so it's not clear whether they actually
work).

NOTE: although this is a simple bug fix, it probably isn't sensible to
cherry-pick it to stable release branches, since its only effect is to
cause incorrectly-written shaders to fail to compile.