Instruction Set
---------------
-From GL_NV_vertex_program
+Core ISA
^^^^^^^^^^^^^^^^^^^^^^^^^
+These opcodes are guaranteed to be available regardless of the driver being
+used.
.. opcode:: ARL - Address Register Load
dst.w = src0.x \times src1.x + src0.y \times src1.y + src2.x
-.. opcode:: FRAC - Fraction
+.. opcode:: FRC - Fraction
.. math::
Considered for removal.
-From GL_NV_vertex_program2
-^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-
.. opcode:: ARA - Address Register Add
TBD
TBD
-.. opcode:: BGNFOR - Begin a For-Loop
-
- dst.x = floor(src.x)
- dst.y = floor(src.y)
- dst.z = floor(src.z)
-
- if (dst.y <= 0)
- pc = [matching ENDFOR] + 1
- endif
-
- Note: The destination must be a loop register.
- The source must be a constant register.
-
-.. note::
-
- Considered for cleanup.
-
-.. note::
-
- Considered for removal.
-
-
-.. opcode:: REP - Repeat
-
- TBD
-
-
.. opcode:: ELSE - Else
TBD
TBD
-.. opcode:: ENDFOR - End a For-Loop
-
- dst.x = dst.x + dst.z
- dst.y = dst.y - 1.0
-
- if (dst.y > 0)
- pc = [matching BGNFOR instruction] + 1
- endif
-
- Note: The destination must be a loop register.
-
-.. note::
-
- Considered for cleanup.
-
-.. note::
-
- Considered for removal.
-
-.. opcode:: ENDREP - End Repeat
-
- TBD
-
-
.. opcode:: PUSHA - Push Address Register On Stack
push(src.x)
Considered for removal.
-From GL_NV_gpu_program4
+Compute ISA
^^^^^^^^^^^^^^^^^^^^^^^^
+These opcodes are primarily provided for special-use computational shaders.
Support for these opcodes indicated by a special pipe capability bit (TBD).
+XXX so let's discuss it, yeah?
+
.. opcode:: CEIL - Ceiling
.. math::
TBD
+.. note::
+
+ Support for CONT is determined by a special capability bit,
+ ``TGSI_CONT_SUPPORTED``. See :ref:`Screen` for more information.
+
-From GL_NV_geometry_program4
+Geometry ISA
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+These opcodes are only supported in geometry shaders; they have no meaning
+in any other type of shader.
.. opcode:: EMIT - Emit
TBD
-From GLSL
+GLSL ISA
^^^^^^^^^^
+These opcodes are part of :term:`GLSL`'s opcode set. Support for these
+opcodes is determined by a special capability bit, ``GLSL``.
.. opcode:: BGNLOOP - Begin a Loop
ps_2_x
^^^^^^^^^^^^
+XXX wait what
.. opcode:: CALLNZ - Subroutine Call If Not Zero
.. _doubleopcodes:
-Double Opcodes
+Double ISA
^^^^^^^^^^^^^^^
-.. opcode:: DADD - Add Double
+The double-precision opcodes reinterpret four-component vectors into
+two-component vectors with doubled precision in each component.
+
+Support for these opcodes is XXX undecided. :T
+
+.. opcode:: DADD - Add
.. math::
dst.zw = src0.zw + src1.zw
-.. opcode:: DDIV - Divide Double
+.. opcode:: DDIV - Divide
.. math::
dst.zw = src0.zw / src1.zw
-.. opcode:: DSEQ - Set Double on Equal
+.. opcode:: DSEQ - Set on Equal
.. math::
dst.zw = src0.zw == src1.zw ? 1.0F : 0.0F
-.. opcode:: DSLT - Set Double on Less than
+.. opcode:: DSLT - Set on Less than
.. math::
dst.zw = src0.zw < src1.zw ? 1.0F : 0.0F
-.. opcode:: DFRAC - Double Fraction
+.. opcode:: DFRAC - Fraction
.. math::
dst.zw = src.zw - \lfloor src.zw\rfloor
-.. opcode:: DFRACEXP - Convert Double Number to Fractional and Integral Components
+.. opcode:: DFRACEXP - Convert Number to Fractional and Integral Components
+
+Like the ``frexp()`` routine in many math libraries, this opcode stores the
+exponent of its source to ``dst0``, and the significand to ``dst1``, such that
+:math:`dst1 \times 2^{dst0} = src` .
.. math::
- dst0.xy = frexp(src.xy, dst1.xy)
+ dst0.xy = exp(src.xy)
- dst0.zw = frexp(src.zw, dst1.zw)
+ dst1.xy = frac(src.xy)
-.. opcode:: DLDEXP - Multiple Double Number by Integral Power of 2
+ dst0.zw = exp(src.zw)
+
+ dst1.zw = frac(src.zw)
+
+.. opcode:: DLDEXP - Multiply Number by Integral Power of 2
+
+This opcode is the inverse of :opcode:`DFRACEXP`.
.. math::
- dst.xy = ldexp(src0.xy, src1.xy)
+ dst.xy = src0.xy \times 2^{src1.xy}
- dst.zw = ldexp(src0.zw, src1.zw)
+ dst.zw = src0.zw \times 2^{src1.zw}
-.. opcode:: DMIN - Minimum Double
+.. opcode:: DMIN - Minimum
.. math::
dst.zw = min(src0.zw, src1.zw)
-.. opcode:: DMAX - Maximum Double
+.. opcode:: DMAX - Maximum
.. math::
dst.zw = max(src0.zw, src1.zw)
-.. opcode:: DMUL - Multiply Double
+.. opcode:: DMUL - Multiply
.. math::
dst.zw = src0.zw \times src1.zw
-.. opcode:: DMAD - Multiply And Add Doubles
+.. opcode:: DMAD - Multiply And Add
.. math::
dst.zw = src0.zw \times src1.zw + src2.zw
-.. opcode:: DRCP - Reciprocal Double
+.. opcode:: DRCP - Reciprocal
.. math::
dst.zw = \frac{1}{src.zw}
-.. opcode:: DSQRT - Square root double
+.. opcode:: DSQRT - Square Root
.. math::
---------------
+Declaration
+^^^^^^^^^^^
+
+
+Declares a register that is will be referenced as an operand in Instruction
+tokens.
+
+File field contains register file that is being declared and is one
+of TGSI_FILE.
+
+UsageMask field specifies which of the register components can be accessed
+and is one of TGSI_WRITEMASK.
+
+Interpolate field is only valid for fragment shader INPUT register files.
+It specifes the way input is being interpolated by the rasteriser and is one
+of TGSI_INTERPOLATE.
+
+If Dimension flag is set to 1, a Declaration Dimension token follows.
+
+If Semantic flag is set to 1, a Declaration Semantic token follows.
+
+CylindricalWrap bitfield is only valid for fragment shader INPUT register
+files. It specifies which register components should be subject to cylindrical
+wrapping when interpolating by the rasteriser. If TGSI_CYLINDRICAL_WRAP_X
+is set to 1, the X component should be interpolated according to cylindrical
+wrapping rules.
+
+
Declaration Semantic
^^^^^^^^^^^^^^^^^^^^^^^^
"""""""""""""""""""
PSIZE, or point size, is used to specify point sizes per-vertex. It should
-be in ``(p, n, x, f)`` format, where ``p`` is the point size, ``n`` is the minimum
-size, ``x`` is the maximum size, and ``f`` is the fade threshold.
-
-XXX this is arb_vp. is this what we actually do? should double-check...
+be in ``(s, 0, 0, 1)`` format, where ``s`` is the (possibly clamped) point size.
+Only the first component matters when writing from the vertex shader.
When using this semantic, be sure to set the appropriate state in the
:ref:`rasterizer` first.
Texture Sampling and Texture Formats
------------------------------------
-This table shows how texture image components are returned as (x,y,z,w)
-tuples by TGSI texture instructions, such as TEX, TXD, and TXP.
-For reference, OpenGL and Direct3D conventions are shown as well.
+This table shows how texture image components are returned as (x,y,z,w) tuples
+by TGSI texture instructions, such as :opcode:`TEX`, :opcode:`TXD`, and
+:opcode:`TXP`. For reference, OpenGL and Direct3D conventions are shown as
+well.
+--------------------+--------------+--------------------+--------------+
| Texture Components | Gallium | OpenGL | Direct3D 9 |
+====================+==============+====================+==============+
-| R | XXX TBD | (r, 0, 0, 1) | (r, 1, 1, 1) |
+| R | (r, 0, 0, 1) | (r, 0, 0, 1) | (r, 1, 1, 1) |
+--------------------+--------------+--------------------+--------------+
-| RG | XXX TBD | (r, g, 0, 1) | (r, g, 1, 1) |
+| RG | (r, g, 0, 1) | (r, g, 0, 1) | (r, g, 1, 1) |
+--------------------+--------------+--------------------+--------------+
| RGB | (r, g, b, 1) | (r, g, b, 1) | (r, g, b, 1) |
+--------------------+--------------+--------------------+--------------+
.. [#envmap-bumpmap] http://www.opengl.org/registry/specs/ATI/envmap_bumpmap.txt
.. [#depth-tex-mode] the default is (z, z, z, 1) but may also be (0, 0, 0, z)
- or (z, z, z, z) depending on the value of GL_DEPTH_TEXTURE_MODE.
+ or (z, z, z, z) depending on the value of GL_DEPTH_TEXTURE_MODE.
projects / mesa.git / blobdiff