glsl: Allow precision qualifiers for sampler types

GLSL 1.30 doesn't allow precision qualifiers on sampler types,
but in GLSL ES, sampler types are also allowed. This seems like
an oversight (since the intention of including these in GLSL 1.30
is to allow compatibility with ES shaders).

Currently, Mesa allows "default" precision qualifiers to be set for
sampler types in GLSL (commit d5948f2). This patch makes it follow
GLSL ES rules and also allow declaring sampler variables with a
precision qualifier in GLSL 1.30 (and later). e.g.
uniform lowp sampler2D sampler;

This fixes a shader compilation error in Khronos OpenGL conformance
test "depth_texture_mipmap".

V2: Update comments.
Signed-off-by: Ian Romanick <idr@lists.freedesktop.org>

Signed-off-by: Anuj Phogat <anuj.phogat@gmail.com>
Reviewed-by: Ian Romanick <idr@lists.freedesktop.org>
Cc: <mesa-stable@lists.freedesktop.org>
(cherry picked from commit 9c0b7be964f0cbb707ed11c2526a30eda5254d2e)
mesa: Rip out more extension checking from texformat.c.

You should only be flagging the formats as supported if you support them
anyway.

NOTE: This is a candidate for the 9.2 branch. (required for next commit)
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
(cherry picked from commit b188467fdf71d8f4c5fab4aafae1253f64d9aab4)
mesa: Don't choose S3TC for generic compression if we can't compress.

If the app is asking us to do GL_COMPRESSED_RGBA, then the app obviously
doesn't have pre-compressed data to hand us.  So don't choose a storage
format that we won't actually be able to compress and store.

Fixes black screen in warzone2100 when libtxc_dxtn is not present.  Also
66 piglit tests.

NOTE: This is a candidate for the 9.2 branch.
Reported-by: Paul Wise <pabs@debian.org>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
(cherry picked from commit bdf3f50e9a85e4c063b46ceaf23bceb07b06b82e)
i965/vs: Detect GRF sources in split_virtual_grfs send-from-GRF code.

It is incorrect to assume that src[0] of a SEND-from-GRF opcode is the GRF.
VS_OPCODE_PULL_CONSTANT_LOAD_GEN7 uses an IMM as src[0], and stores the
GRF as src[1].

To be safe, loop over all the source registers and mark any GRFs.  We
probably won't ever have more than one, but it's simpler to just check
all three rather than attempting to bail early.

Fixes assertion failures in Unigine Sanctuary since we started making
register allocation rely on split_virtual_grfs working.  (The register
classes were actually sufficient, we were just interpreting an IMM as
a virtual GRF number.)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=68637
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Cc: mesa-stable@lists.freedesktop.org
(cherry picked from commit 4e3d1712a223f9f0b4ff4a34b9b5447a92877347)
i965/fs: Detect GRF sources in split_virtual_grfs send-from-GRF code.

It is incorrect to assume that src[0] of a SEND-from-GRF opcode is the
GRF.  For example, FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD uses src[1] for
the GRF.

To be safe, loop over all the source registers and mark any GRFs.  We
probably won't ever have more than one, but it's simpler to just check
all three rather than attempting to bail early.

Not observed to fix anything yet, but likely to.  Parallels the bug fix
in the previous commit, which actually does fix known failures.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Cc: mesa-stable@lists.freedesktop.org
(cherry picked from commit a35b32025011eeac01f2e5a476dbf3ac132a61b3)
mesa: Note that 89a665e should not be picked

See also:

http://lists.freedesktop.org/archives/mesa-stable/2013-September/000251.html
http://lists.freedesktop.org/archives/mesa-stable/2013-September/000252.html

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>