Some instructions, like :opcode:`I2F`, permit re-interpretation of vector
components as integers. Other instructions permit using registers as
-two-component vectors with double precision; see :ref:`Double Opcodes`.
+two-component vectors with double precision; see :ref:`doubleopcodes`.
When an instruction has a scalar result, the result is usually copied into
each of the components of *dst*. When this happens, the result is said to be
*replicated* to *dst*. :opcode:`RCP` is one such instruction.
+Modifiers
+^^^^^^^^^^^^^^^
+
+TGSI supports modifiers on inputs (as well as saturate modifier on instructions).
+
+For inputs which have a floating point type, both absolute value and negation
+modifiers are supported (with absolute value being applied first).
+TGSI_OPCODE_MOV is considered to have float input type for applying modifiers.
+
+For inputs which have signed or unsigned type only the negate modifier is
+supported.
+
Instruction Set
---------------
.. math::
- dst.x = \lfloor src.x\rfloor
+ dst.x = (int) \lfloor src.x\rfloor
- dst.y = \lfloor src.y\rfloor
+ dst.y = (int) \lfloor src.y\rfloor
- dst.z = \lfloor src.z\rfloor
+ dst.z = (int) \lfloor src.z\rfloor
- dst.w = \lfloor src.w\rfloor
+ dst.w = (int) \lfloor src.w\rfloor
.. opcode:: MOV - Move
.. math::
- dst.x = 1
-
- dst.y = max(src.x, 0)
-
- dst.z = (src.x > 0) ? max(src.y, 0)^{clamp(src.w, -128, 128))} : 0
-
- dst.w = 1
+ dst.x &= 1 \\
+ dst.y &= max(src.x, 0) \\
+ dst.z &= (src.x > 0) ? max(src.y, 0)^{clamp(src.w, -128, 128))} : 0 \\
+ dst.w &= 1
.. opcode:: RCP - Reciprocal
.. opcode:: RSQ - Reciprocal Square Root
-This instruction replicates its result.
+This instruction replicates its result. The results are undefined for src <= 0.
.. math::
- dst = \frac{1}{\sqrt{|src.x|}}
+ dst = \frac{1}{\sqrt{src.x}}
-.. opcode:: EXP - Approximate Exponential Base 2
+.. opcode:: SQRT - Square Root
+
+This instruction replicates its result. The results are undefined for src < 0.
.. math::
- dst.x = 2^{\lfloor src.x\rfloor}
+ dst = {\sqrt{src.x}}
- dst.y = src.x - \lfloor src.x\rfloor
- dst.z = 2^{src.x}
+.. opcode:: EXP - Approximate Exponential Base 2
- dst.w = 1
+.. math::
+
+ dst.x &= 2^{\lfloor src.x\rfloor} \\
+ dst.y &= src.x - \lfloor src.x\rfloor \\
+ dst.z &= 2^{src.x} \\
+ dst.w &= 1
.. opcode:: LOG - Approximate Logarithm Base 2
.. math::
- dst.x = \lfloor\log_2{|src.x|}\rfloor
-
- dst.y = \frac{|src.x|}{2^{\lfloor\log_2{|src.x|}\rfloor}}
-
- dst.z = \log_2{|src.x|}
-
- dst.w = 1
+ dst.x &= \lfloor\log_2{|src.x|}\rfloor \\
+ dst.y &= \frac{|src.x|}{2^{\lfloor\log_2{|src.x|}\rfloor}} \\
+ dst.z &= \log_2{|src.x|} \\
+ dst.w &= 1
.. opcode:: MUL - Multiply
.. math::
- dst.x = 1
-
- dst.y = src0.y \times src1.y
-
- dst.z = src0.z
-
- dst.w = src1.w
+ dst.x &= 1\\
+ dst.y &= src0.y \times src1.y\\
+ dst.z &= src0.z\\
+ dst.w &= src1.w
.. opcode:: MIN - Minimum
.. math::
- dst.x = (src0.x < src1.x) ? 1 : 0
+ dst.x = (src0.x < src1.x) ? 1.0F : 0.0F
- dst.y = (src0.y < src1.y) ? 1 : 0
+ dst.y = (src0.y < src1.y) ? 1.0F : 0.0F
- dst.z = (src0.z < src1.z) ? 1 : 0
+ dst.z = (src0.z < src1.z) ? 1.0F : 0.0F
- dst.w = (src0.w < src1.w) ? 1 : 0
+ dst.w = (src0.w < src1.w) ? 1.0F : 0.0F
.. opcode:: SGE - Set On Greater Equal Than
.. math::
- dst.x = (src0.x >= src1.x) ? 1 : 0
+ dst.x = (src0.x >= src1.x) ? 1.0F : 0.0F
- dst.y = (src0.y >= src1.y) ? 1 : 0
+ dst.y = (src0.y >= src1.y) ? 1.0F : 0.0F
- dst.z = (src0.z >= src1.z) ? 1 : 0
+ dst.z = (src0.z >= src1.z) ? 1.0F : 0.0F
- dst.w = (src0.w >= src1.w) ? 1 : 0
+ dst.w = (src0.w >= src1.w) ? 1.0F : 0.0F
.. opcode:: MAD - Multiply And Add
dst.w = src0.w \times src1.w + (1 - src0.w) \times src2.w
-.. opcode:: CND - Condition
+.. opcode:: FMA - Fused Multiply-Add
+
+Perform a * b + c with no intermediate rounding step.
.. math::
- dst.x = (src2.x > 0.5) ? src0.x : src1.x
+ dst.x = src0.x \times src1.x + src2.x
- dst.y = (src2.y > 0.5) ? src0.y : src1.y
+ dst.y = src0.y \times src1.y + src2.y
- dst.z = (src2.z > 0.5) ? src0.z : src1.z
+ dst.z = src0.z \times src1.z + src2.z
- dst.w = (src2.w > 0.5) ? src0.w : src1.w
+ dst.w = src0.w \times src1.w + src2.w
.. opcode:: DP2A - 2-component Dot Product And Add
.. opcode:: FLR - Floor
-This is identical to :opcode:`ARL`.
-
.. math::
dst.x = \lfloor src.x\rfloor
dst.w = |src.w|
-.. opcode:: RCC - Reciprocal Clamped
-
-This instruction replicates its result.
-
-XXX cleanup on aisle three
-
-.. math::
-
- dst = (1 / src.x) > 0 ? clamp(1 / src.x, 5.42101e-020, 1.884467e+019) : clamp(1 / src.x, -1.884467e+019, -5.42101e-020)
-
-
.. opcode:: DPH - Homogeneous Dot Product
This instruction replicates its result.
dst = \cos{src.x}
-.. opcode:: DDX - Derivative Relative To X
+.. opcode:: DDX, DDX_FINE - Derivative Relative To X
+
+The fine variant is only used when ``PIPE_CAP_TGSI_FS_FINE_DERIVATIVE`` is
+advertised. When it is, the fine version guarantees one derivative per row
+while DDX is allowed to be the same for the entire 2x2 quad.
.. math::
dst.w = partialx(src.w)
-.. opcode:: DDY - Derivative Relative To Y
+.. opcode:: DDY, DDY_FINE - Derivative Relative To Y
+
+The fine variant is only used when ``PIPE_CAP_TGSI_FS_FINE_DERIVATIVE`` is
+advertised. When it is, the fine version guarantees one derivative per column
+while DDY is allowed to be the same for the entire 2x2 quad.
.. math::
dst.w = partialy(src.w)
-.. opcode:: KILP - Predicated Discard
-
- discard
-
-
.. opcode:: PK2H - Pack Two 16-bit Floats
TBD
TBD
-.. opcode:: RFL - Reflection Vector
+.. opcode:: SEQ - Set On Equal
.. math::
- dst.x = 2 \times (src0.x \times src1.x + src0.y \times src1.y + src0.z \times src1.z) / (src0.x \times src0.x + src0.y \times src0.y + src0.z \times src0.z) \times src0.x - src1.x
+ dst.x = (src0.x == src1.x) ? 1.0F : 0.0F
- dst.y = 2 \times (src0.x \times src1.x + src0.y \times src1.y + src0.z \times src1.z) / (src0.x \times src0.x + src0.y \times src0.y + src0.z \times src0.z) \times src0.y - src1.y
+ dst.y = (src0.y == src1.y) ? 1.0F : 0.0F
- dst.z = 2 \times (src0.x \times src1.x + src0.y \times src1.y + src0.z \times src1.z) / (src0.x \times src0.x + src0.y \times src0.y + src0.z \times src0.z) \times src0.z - src1.z
+ dst.z = (src0.z == src1.z) ? 1.0F : 0.0F
- dst.w = 1
-
-.. note::
-
- Considered for removal.
+ dst.w = (src0.w == src1.w) ? 1.0F : 0.0F
-.. opcode:: SEQ - Set On Equal
+.. opcode:: SGT - Set On Greater Than
.. math::
- dst.x = (src0.x == src1.x) ? 1 : 0
+ dst.x = (src0.x > src1.x) ? 1.0F : 0.0F
- dst.y = (src0.y == src1.y) ? 1 : 0
+ dst.y = (src0.y > src1.y) ? 1.0F : 0.0F
- dst.z = (src0.z == src1.z) ? 1 : 0
+ dst.z = (src0.z > src1.z) ? 1.0F : 0.0F
- dst.w = (src0.w == src1.w) ? 1 : 0
+ dst.w = (src0.w > src1.w) ? 1.0F : 0.0F
-.. opcode:: SFL - Set On False
+.. opcode:: SIN - Sine
This instruction replicates its result.
.. math::
- dst = 0
-
-.. note::
-
- Considered for removal.
+ dst = \sin{src.x}
-.. opcode:: SGT - Set On Greater Than
+.. opcode:: SLE - Set On Less Equal Than
.. math::
- dst.x = (src0.x > src1.x) ? 1 : 0
-
- dst.y = (src0.y > src1.y) ? 1 : 0
+ dst.x = (src0.x <= src1.x) ? 1.0F : 0.0F
- dst.z = (src0.z > src1.z) ? 1 : 0
+ dst.y = (src0.y <= src1.y) ? 1.0F : 0.0F
- dst.w = (src0.w > src1.w) ? 1 : 0
+ dst.z = (src0.z <= src1.z) ? 1.0F : 0.0F
+ dst.w = (src0.w <= src1.w) ? 1.0F : 0.0F
-.. opcode:: SIN - Sine
-This instruction replicates its result.
+.. opcode:: SNE - Set On Not Equal
.. math::
- dst = \sin{src.x}
+ dst.x = (src0.x != src1.x) ? 1.0F : 0.0F
+ dst.y = (src0.y != src1.y) ? 1.0F : 0.0F
-.. opcode:: SLE - Set On Less Equal Than
+ dst.z = (src0.z != src1.z) ? 1.0F : 0.0F
-.. math::
+ dst.w = (src0.w != src1.w) ? 1.0F : 0.0F
- dst.x = (src0.x <= src1.x) ? 1 : 0
- dst.y = (src0.y <= src1.y) ? 1 : 0
+.. opcode:: TEX - Texture Lookup
- dst.z = (src0.z <= src1.z) ? 1 : 0
+ for array textures src0.y contains the slice for 1D,
+ and src0.z contain the slice for 2D.
- dst.w = (src0.w <= src1.w) ? 1 : 0
+ for shadow textures with no arrays (and not cube map),
+ src0.z contains the reference value.
+ for shadow textures with arrays, src0.z contains
+ the reference value for 1D arrays, and src0.w contains
+ the reference value for 2D arrays and cube maps.
-.. opcode:: SNE - Set On Not Equal
+ for cube map array shadow textures, the reference value
+ cannot be passed in src0.w, and TEX2 must be used instead.
.. math::
- dst.x = (src0.x != src1.x) ? 1 : 0
+ coord = src0
- dst.y = (src0.y != src1.y) ? 1 : 0
+ shadow_ref = src0.z or src0.w (optional)
- dst.z = (src0.z != src1.z) ? 1 : 0
+ unit = src1
- dst.w = (src0.w != src1.w) ? 1 : 0
+ dst = texture\_sample(unit, coord, shadow_ref)
-.. opcode:: STR - Set On True
+.. opcode:: TEX2 - Texture Lookup (for shadow cube map arrays only)
-This instruction replicates its result.
+ this is the same as TEX, but uses another reg to encode the
+ reference value.
.. math::
- dst = 1
+ coord = src0
+ shadow_ref = src1.x
-.. opcode:: TEX - Texture Lookup
+ unit = src2
- TBD
+ dst = texture\_sample(unit, coord, shadow_ref)
-.. opcode:: TXD - Texture Lookup with Derivatives
- TBD
+.. opcode:: TXD - Texture Lookup with Derivatives
-.. opcode:: TXP - Projective Texture Lookup
+.. math::
- TBD
+ coord = src0
+ ddx = src1
-.. opcode:: UP2H - Unpack Two 16-Bit Floats
+ ddy = src2
- TBD
+ unit = src3
-.. note::
+ dst = texture\_sample\_deriv(unit, coord, ddx, ddy)
- Considered for removal.
-.. opcode:: UP2US - Unpack Two Unsigned 16-Bit Scalars
+.. opcode:: TXP - Projective Texture Lookup
- TBD
+.. math::
-.. note::
+ coord.x = src0.x / src0.w
- Considered for removal.
+ coord.y = src0.y / src0.w
-.. opcode:: UP4B - Unpack Four Signed 8-Bit Values
+ coord.z = src0.z / src0.w
- TBD
+ coord.w = src0.w
-.. note::
+ unit = src1
- Considered for removal.
+ dst = texture\_sample(unit, coord)
-.. opcode:: UP4UB - Unpack Four Unsigned 8-Bit Scalars
+
+.. opcode:: UP2H - Unpack Two 16-Bit Floats
TBD
Considered for removal.
-.. opcode:: X2D - 2D Coordinate Transformation
+.. opcode:: UP2US - Unpack Two Unsigned 16-Bit Scalars
-.. math::
+ TBD
- dst.x = src0.x + src1.x \times src2.x + src1.y \times src2.y
+.. note::
- dst.y = src0.y + src1.x \times src2.z + src1.y \times src2.w
+ Considered for removal.
- dst.z = src0.x + src1.x \times src2.x + src1.y \times src2.y
+.. opcode:: UP4B - Unpack Four Signed 8-Bit Values
- dst.w = src0.y + src1.x \times src2.z + src1.y \times src2.w
+ TBD
.. note::
Considered for removal.
-
-.. opcode:: ARA - Address Register Add
+.. opcode:: UP4UB - Unpack Four Unsigned 8-Bit Scalars
TBD
Considered for removal.
+
.. opcode:: ARR - Address Register Load With Round
.. math::
- dst.x = round(src.x)
-
- dst.y = round(src.y)
-
- dst.z = round(src.z)
-
- dst.w = round(src.w)
-
-
-.. opcode:: BRA - Branch
-
- pc = target
-
-.. note::
-
- Considered for removal.
-
-.. opcode:: CAL - Subroutine Call
-
- push(pc)
- pc = target
+ dst.x = (int) round(src.x)
+ dst.y = (int) round(src.y)
-.. opcode:: RET - Subroutine Call Return
+ dst.z = (int) round(src.z)
- pc = pop()
+ dst.w = (int) round(src.w)
.. opcode:: SSG - Set Sign
dst.w = (src0.w < 0) ? src1.w : src2.w
-.. opcode:: KIL - Conditional Discard
+.. opcode:: KILL_IF - Conditional Discard
+
+ Conditional discard. Allowed in fragment shaders only.
.. math::
endif
+.. opcode:: KILL - Discard
+
+ Unconditional discard. Allowed in fragment shaders only.
+
+
.. opcode:: SCS - Sine Cosine
.. math::
.. opcode:: TXB - Texture Lookup With Bias
- TBD
+ for cube map array textures and shadow cube maps, the bias value
+ cannot be passed in src0.w, and TXB2 must be used instead.
+
+ if the target is a shadow texture, the reference value is always
+ in src.z (this prevents shadow 3d and shadow 2d arrays from
+ using this instruction, but this is not needed).
+
+.. math::
+
+ coord.x = src0.x
+
+ coord.y = src0.y
+
+ coord.z = src0.z
+
+ coord.w = none
+
+ bias = src0.w
+
+ unit = src1
+ dst = texture\_sample(unit, coord, bias)
-.. opcode:: NRM - 3-component Vector Normalise
+
+.. opcode:: TXB2 - Texture Lookup With Bias (some cube maps only)
+
+ this is the same as TXB, but uses another reg to encode the
+ lod bias value for cube map arrays and shadow cube maps.
+ Presumably shadow 2d arrays and shadow 3d targets could use
+ this encoding too, but this is not legal.
+
+ shadow cube map arrays are neither possible nor required.
.. math::
- dst.x = src.x / (src.x \times src.x + src.y \times src.y + src.z \times src.z)
+ coord = src0
- dst.y = src.y / (src.x \times src.x + src.y \times src.y + src.z \times src.z)
+ bias = src1.x
- dst.z = src.z / (src.x \times src.x + src.y \times src.y + src.z \times src.z)
+ unit = src2
- dst.w = 1
+ dst = texture\_sample(unit, coord, bias)
.. opcode:: DIV - Divide
dst = src0.x \times src1.x + src0.y \times src1.y
-.. opcode:: TXL - Texture Lookup With LOD
+.. opcode:: TXL - Texture Lookup With explicit LOD
- TBD
+ for cube map array textures, the explicit lod value
+ cannot be passed in src0.w, and TXL2 must be used instead.
+ if the target is a shadow texture, the reference value is always
+ in src.z (this prevents shadow 3d / 2d array / cube targets from
+ using this instruction, but this is not needed).
-.. opcode:: BRK - Break
+.. math::
- TBD
+ coord.x = src0.x
+ coord.y = src0.y
-.. opcode:: IF - If
+ coord.z = src0.z
- TBD
+ coord.w = none
+ lod = src0.w
-.. opcode:: ELSE - Else
+ unit = src1
- TBD
+ dst = texture\_sample(unit, coord, lod)
-.. opcode:: ENDIF - End If
+.. opcode:: TXL2 - Texture Lookup With explicit LOD (for cube map arrays only)
- TBD
+ this is the same as TXL, but uses another reg to encode the
+ explicit lod value.
+ Presumably shadow 3d / 2d array / cube targets could use
+ this encoding too, but this is not legal.
+
+ shadow cube map arrays are neither possible nor required.
+
+.. math::
+
+ coord = src0
+
+ lod = src1.x
+
+ unit = src2
+
+ dst = texture\_sample(unit, coord, lod)
.. opcode:: PUSHA - Push Address Register On Stack
Considered for removal.
+.. opcode:: CALLNZ - Subroutine Call If Not Zero
+
+ TBD
+
+.. note::
+
+ Considered for cleanup.
+
+.. note::
+
+ Considered for removal.
+
+
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?
+XXX doesn't look like most of the opcodes really belong here.
.. opcode:: CEIL - Ceiling
dst.w = \lceil src.w\rceil
-.. opcode:: I2F - Integer To Float
+.. opcode:: TRUNC - Truncate
.. math::
- dst.x = (float) src.x
+ dst.x = trunc(src.x)
- dst.y = (float) src.y
+ dst.y = trunc(src.y)
- dst.z = (float) src.z
+ dst.z = trunc(src.z)
- dst.w = (float) src.w
+ dst.w = trunc(src.w)
-.. opcode:: NOT - Bitwise Not
+.. opcode:: MOD - Modulus
.. math::
- dst.x = ~src.x
+ dst.x = src0.x \bmod src1.x
- dst.y = ~src.y
+ dst.y = src0.y \bmod src1.y
- dst.z = ~src.z
+ dst.z = src0.z \bmod src1.z
- dst.w = ~src.w
+ dst.w = src0.w \bmod src1.w
-.. opcode:: TRUNC - Truncate
+.. opcode:: UARL - Integer Address Register Load
-.. math::
+ Moves the contents of the source register, assumed to be an integer, into the
+ destination register, which is assumed to be an address (ADDR) register.
- dst.x = trunc(src.x)
- dst.y = trunc(src.y)
+.. opcode:: SAD - Sum Of Absolute Differences
- dst.z = trunc(src.z)
+.. math::
- dst.w = trunc(src.w)
+ dst.x = |src0.x - src1.x| + src2.x
+ dst.y = |src0.y - src1.y| + src2.y
-.. opcode:: SHL - Shift Left
+ dst.z = |src0.z - src1.z| + src2.z
-.. math::
+ dst.w = |src0.w - src1.w| + src2.w
+
+
+.. opcode:: TXF - Texel Fetch
- dst.x = src0.x << src1.x
+ As per NV_gpu_shader4, extract a single texel from a specified texture
+ image. The source sampler may not be a CUBE or SHADOW. src 0 is a
+ four-component signed integer vector used to identify the single texel
+ accessed. 3 components + level. Just like texture instructions, an optional
+ offset vector is provided, which is subject to various driver restrictions
+ (regarding range, source of offsets).
+ TXF(uint_vec coord, int_vec offset).
- dst.y = src0.y << src1.x
- dst.z = src0.z << src1.x
+.. opcode:: TXQ - Texture Size Query
- dst.w = src0.w << src1.x
+ As per NV_gpu_program4, retrieve the dimensions of the texture depending on
+ the target. For 1D (width), 2D/RECT/CUBE (width, height), 3D (width, height,
+ depth), 1D array (width, layers), 2D array (width, height, layers).
+ Also return the number of accessible levels (last_level - first_level + 1)
+ in W.
+ For components which don't return a resource dimension, their value
+ is undefined.
-.. opcode:: SHR - Shift Right
.. math::
- dst.x = src0.x >> src1.x
+ lod = src0.x
- dst.y = src0.y >> src1.x
+ dst.x = texture\_width(unit, lod)
- dst.z = src0.z >> src1.x
+ dst.y = texture\_height(unit, lod)
- dst.w = src0.w >> src1.x
+ dst.z = texture\_depth(unit, lod)
+ dst.w = texture\_levels(unit)
-.. opcode:: AND - Bitwise And
+.. opcode:: TG4 - Texture Gather
-.. math::
+ As per ARB_texture_gather, gathers the four texels to be used in a bi-linear
+ filtering operation and packs them into a single register. Only works with
+ 2D, 2D array, cubemaps, and cubemaps arrays. For 2D textures, only the
+ addressing modes of the sampler and the top level of any mip pyramid are
+ used. Set W to zero. It behaves like the TEX instruction, but a filtered
+ sample is not generated. The four samples that contribute to filtering are
+ placed into xyzw in clockwise order, starting with the (u,v) texture
+ coordinate delta at the following locations (-, +), (+, +), (+, -), (-, -),
+ where the magnitude of the deltas are half a texel.
- dst.x = src0.x & src1.x
+ PIPE_CAP_TEXTURE_SM5 enhances this instruction to support shadow per-sample
+ depth compares, single component selection, and a non-constant offset. It
+ doesn't allow support for the GL independent offset to get i0,j0. This would
+ require another CAP is hw can do it natively. For now we lower that before
+ TGSI.
- dst.y = src0.y & src1.y
+.. math::
- dst.z = src0.z & src1.z
+ coord = src0
- dst.w = src0.w & src1.w
+ component = src1
+ dst = texture\_gather4 (unit, coord, component)
-.. opcode:: OR - Bitwise Or
+(with SM5 - cube array shadow)
.. math::
- dst.x = src0.x | src1.x
-
- dst.y = src0.y | src1.y
+ coord = src0
- dst.z = src0.z | src1.z
+ compare = src1
- dst.w = src0.w | src1.w
+ dst = texture\_gather (uint, coord, compare)
+.. opcode:: LODQ - level of detail query
-.. opcode:: MOD - Modulus
+ Compute the LOD information that the texture pipe would use to access the
+ texture. The Y component contains the computed LOD lambda_prime. The X
+ component contains the LOD that will be accessed, based on min/max lod's
+ and mipmap filters.
.. math::
- dst.x = src0.x \bmod src1.x
+ coord = src0
- dst.y = src0.y \bmod src1.y
+ dst.xy = lodq(uint, coord);
- dst.z = src0.z \bmod src1.z
+Integer ISA
+^^^^^^^^^^^^^^^^^^^^^^^^
+These opcodes are used for integer operations.
+Support for these opcodes indicated by PIPE_SHADER_CAP_INTEGERS (all of them?)
- dst.w = src0.w \bmod src1.w
+.. opcode:: I2F - Signed Integer To Float
-.. opcode:: XOR - Bitwise Xor
+ Rounding is unspecified (round to nearest even suggested).
.. math::
- dst.x = src0.x \oplus src1.x
+ dst.x = (float) src.x
- dst.y = src0.y \oplus src1.y
+ dst.y = (float) src.y
- dst.z = src0.z \oplus src1.z
+ dst.z = (float) src.z
- dst.w = src0.w \oplus src1.w
+ dst.w = (float) src.w
-.. opcode:: SAD - Sum Of Absolute Differences
+.. opcode:: U2F - Unsigned Integer To Float
+
+ Rounding is unspecified (round to nearest even suggested).
.. math::
- dst.x = |src0.x - src1.x| + src2.x
+ dst.x = (float) src.x
- dst.y = |src0.y - src1.y| + src2.y
+ dst.y = (float) src.y
- dst.z = |src0.z - src1.z| + src2.z
+ dst.z = (float) src.z
- dst.w = |src0.w - src1.w| + src2.w
+ dst.w = (float) src.w
-.. opcode:: TXF - Texel Fetch
+.. opcode:: F2I - Float to Signed Integer
- TBD
+ Rounding is towards zero (truncate).
+ Values outside signed range (including NaNs) produce undefined results.
+.. math::
-.. opcode:: TXQ - Texture Size Query
+ dst.x = (int) src.x
- TBD
+ dst.y = (int) src.y
+ dst.z = (int) src.z
-.. opcode:: CONT - Continue
+ dst.w = (int) src.w
- TBD
-.. note::
+.. opcode:: F2U - Float to Unsigned Integer
- Support for CONT is determined by a special capability bit,
- ``TGSI_CONT_SUPPORTED``. See :ref:`Screen` for more information.
+ Rounding is towards zero (truncate).
+ Values outside unsigned range (including NaNs) produce undefined results.
+.. math::
-Geometry ISA
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ dst.x = (unsigned) src.x
+
+ dst.y = (unsigned) src.y
+
+ dst.z = (unsigned) src.z
+
+ dst.w = (unsigned) src.w
+
+
+.. opcode:: UADD - Integer Add
+
+ This instruction works the same for signed and unsigned integers.
+ The low 32bit of the result is returned.
+
+.. math::
+
+ dst.x = src0.x + src1.x
+
+ dst.y = src0.y + src1.y
+
+ dst.z = src0.z + src1.z
+
+ dst.w = src0.w + src1.w
+
+
+.. opcode:: UMAD - Integer Multiply And Add
+
+ This instruction works the same for signed and unsigned integers.
+ The multiplication returns the low 32bit (as does the result itself).
+
+.. math::
+
+ dst.x = src0.x \times src1.x + src2.x
+
+ dst.y = src0.y \times src1.y + src2.y
+
+ dst.z = src0.z \times src1.z + src2.z
+
+ dst.w = src0.w \times src1.w + src2.w
+
+
+.. opcode:: UMUL - Integer Multiply
+
+ This instruction works the same for signed and unsigned integers.
+ The low 32bit of the result is returned.
+
+.. math::
+
+ dst.x = src0.x \times src1.x
+
+ dst.y = src0.y \times src1.y
+
+ dst.z = src0.z \times src1.z
+
+ dst.w = src0.w \times src1.w
+
+
+.. opcode:: IMUL_HI - Signed Integer Multiply High Bits
+
+ The high 32bits of the multiplication of 2 signed integers are returned.
+
+.. math::
+
+ dst.x = (src0.x \times src1.x) >> 32
+
+ dst.y = (src0.y \times src1.y) >> 32
+
+ dst.z = (src0.z \times src1.z) >> 32
+
+ dst.w = (src0.w \times src1.w) >> 32
+
+
+.. opcode:: UMUL_HI - Unsigned Integer Multiply High Bits
+
+ The high 32bits of the multiplication of 2 unsigned integers are returned.
+
+.. math::
+
+ dst.x = (src0.x \times src1.x) >> 32
+
+ dst.y = (src0.y \times src1.y) >> 32
+
+ dst.z = (src0.z \times src1.z) >> 32
+
+ dst.w = (src0.w \times src1.w) >> 32
+
+
+.. opcode:: IDIV - Signed Integer Division
+
+ TBD: behavior for division by zero.
+
+.. math::
+
+ dst.x = src0.x \ src1.x
+
+ dst.y = src0.y \ src1.y
+
+ dst.z = src0.z \ src1.z
+
+ dst.w = src0.w \ src1.w
+
+
+.. opcode:: UDIV - Unsigned Integer Division
+
+ For division by zero, 0xffffffff is returned.
+
+.. math::
+
+ dst.x = src0.x \ src1.x
+
+ dst.y = src0.y \ src1.y
+
+ dst.z = src0.z \ src1.z
+
+ dst.w = src0.w \ src1.w
+
+
+.. opcode:: UMOD - Unsigned Integer Remainder
+
+ If second arg is zero, 0xffffffff is returned.
+
+.. math::
+
+ dst.x = src0.x \ src1.x
+
+ dst.y = src0.y \ src1.y
+
+ dst.z = src0.z \ src1.z
+
+ dst.w = src0.w \ src1.w
+
+
+.. opcode:: NOT - Bitwise Not
+
+.. math::
+
+ dst.x = \sim src.x
+
+ dst.y = \sim src.y
+
+ dst.z = \sim src.z
+
+ dst.w = \sim src.w
+
+
+.. opcode:: AND - Bitwise And
+
+.. math::
+
+ dst.x = src0.x \& src1.x
+
+ dst.y = src0.y \& src1.y
+
+ dst.z = src0.z \& src1.z
+
+ dst.w = src0.w \& src1.w
+
+
+.. opcode:: OR - Bitwise Or
+
+.. math::
+
+ dst.x = src0.x | src1.x
+
+ dst.y = src0.y | src1.y
+
+ dst.z = src0.z | src1.z
+
+ dst.w = src0.w | src1.w
+
+
+.. opcode:: XOR - Bitwise Xor
+
+.. math::
+
+ dst.x = src0.x \oplus src1.x
+
+ dst.y = src0.y \oplus src1.y
+
+ dst.z = src0.z \oplus src1.z
+
+ dst.w = src0.w \oplus src1.w
+
+
+.. opcode:: IMAX - Maximum of Signed Integers
+
+.. math::
+
+ dst.x = max(src0.x, src1.x)
+
+ dst.y = max(src0.y, src1.y)
+
+ dst.z = max(src0.z, src1.z)
+
+ dst.w = max(src0.w, src1.w)
+
+
+.. opcode:: UMAX - Maximum of Unsigned Integers
+
+.. math::
+
+ dst.x = max(src0.x, src1.x)
+
+ dst.y = max(src0.y, src1.y)
+
+ dst.z = max(src0.z, src1.z)
+
+ dst.w = max(src0.w, src1.w)
+
+
+.. opcode:: IMIN - Minimum of Signed Integers
+
+.. math::
+
+ dst.x = min(src0.x, src1.x)
+
+ dst.y = min(src0.y, src1.y)
+
+ dst.z = min(src0.z, src1.z)
+
+ dst.w = min(src0.w, src1.w)
+
+
+.. opcode:: UMIN - Minimum of Unsigned Integers
+
+.. math::
+
+ dst.x = min(src0.x, src1.x)
+
+ dst.y = min(src0.y, src1.y)
+
+ dst.z = min(src0.z, src1.z)
+
+ dst.w = min(src0.w, src1.w)
+
+
+.. opcode:: SHL - Shift Left
+
+ The shift count is masked with 0x1f before the shift is applied.
+
+.. math::
+
+ dst.x = src0.x << (0x1f \& src1.x)
+
+ dst.y = src0.y << (0x1f \& src1.y)
+
+ dst.z = src0.z << (0x1f \& src1.z)
+
+ dst.w = src0.w << (0x1f \& src1.w)
+
+
+.. opcode:: ISHR - Arithmetic Shift Right (of Signed Integer)
+
+ The shift count is masked with 0x1f before the shift is applied.
+
+.. math::
+
+ dst.x = src0.x >> (0x1f \& src1.x)
+
+ dst.y = src0.y >> (0x1f \& src1.y)
+
+ dst.z = src0.z >> (0x1f \& src1.z)
+
+ dst.w = src0.w >> (0x1f \& src1.w)
+
+
+.. opcode:: USHR - Logical Shift Right
+
+ The shift count is masked with 0x1f before the shift is applied.
+
+.. math::
+
+ dst.x = src0.x >> (unsigned) (0x1f \& src1.x)
+
+ dst.y = src0.y >> (unsigned) (0x1f \& src1.y)
+
+ dst.z = src0.z >> (unsigned) (0x1f \& src1.z)
+
+ dst.w = src0.w >> (unsigned) (0x1f \& src1.w)
+
+
+.. opcode:: UCMP - Integer Conditional Move
+
+.. math::
+
+ dst.x = src0.x ? src1.x : src2.x
+
+ dst.y = src0.y ? src1.y : src2.y
+
+ dst.z = src0.z ? src1.z : src2.z
+
+ dst.w = src0.w ? src1.w : src2.w
+
+
+
+.. opcode:: ISSG - Integer Set Sign
+
+.. math::
+
+ dst.x = (src0.x < 0) ? -1 : (src0.x > 0) ? 1 : 0
+
+ dst.y = (src0.y < 0) ? -1 : (src0.y > 0) ? 1 : 0
+
+ dst.z = (src0.z < 0) ? -1 : (src0.z > 0) ? 1 : 0
+
+ dst.w = (src0.w < 0) ? -1 : (src0.w > 0) ? 1 : 0
+
+
+
+.. opcode:: FSLT - Float Set On Less Than (ordered)
+
+ Same comparison as SLT but returns integer instead of 1.0/0.0 float
+
+.. math::
+
+ dst.x = (src0.x < src1.x) ? \sim 0 : 0
+
+ dst.y = (src0.y < src1.y) ? \sim 0 : 0
+
+ dst.z = (src0.z < src1.z) ? \sim 0 : 0
+
+ dst.w = (src0.w < src1.w) ? \sim 0 : 0
+
+
+.. opcode:: ISLT - Signed Integer Set On Less Than
+
+.. math::
+
+ dst.x = (src0.x < src1.x) ? \sim 0 : 0
+
+ dst.y = (src0.y < src1.y) ? \sim 0 : 0
+
+ dst.z = (src0.z < src1.z) ? \sim 0 : 0
+
+ dst.w = (src0.w < src1.w) ? \sim 0 : 0
+
+
+.. opcode:: USLT - Unsigned Integer Set On Less Than
+
+.. math::
+
+ dst.x = (src0.x < src1.x) ? \sim 0 : 0
+
+ dst.y = (src0.y < src1.y) ? \sim 0 : 0
+
+ dst.z = (src0.z < src1.z) ? \sim 0 : 0
+
+ dst.w = (src0.w < src1.w) ? \sim 0 : 0
+
+
+.. opcode:: FSGE - Float Set On Greater Equal Than (ordered)
+
+ Same comparison as SGE but returns integer instead of 1.0/0.0 float
+
+.. math::
+
+ dst.x = (src0.x >= src1.x) ? \sim 0 : 0
+
+ dst.y = (src0.y >= src1.y) ? \sim 0 : 0
+
+ dst.z = (src0.z >= src1.z) ? \sim 0 : 0
+
+ dst.w = (src0.w >= src1.w) ? \sim 0 : 0
+
+
+.. opcode:: ISGE - Signed Integer Set On Greater Equal Than
+
+.. math::
+
+ dst.x = (src0.x >= src1.x) ? \sim 0 : 0
+
+ dst.y = (src0.y >= src1.y) ? \sim 0 : 0
+
+ dst.z = (src0.z >= src1.z) ? \sim 0 : 0
+
+ dst.w = (src0.w >= src1.w) ? \sim 0 : 0
+
+
+.. opcode:: USGE - Unsigned Integer Set On Greater Equal Than
+
+.. math::
+
+ dst.x = (src0.x >= src1.x) ? \sim 0 : 0
+
+ dst.y = (src0.y >= src1.y) ? \sim 0 : 0
+
+ dst.z = (src0.z >= src1.z) ? \sim 0 : 0
+
+ dst.w = (src0.w >= src1.w) ? \sim 0 : 0
+
+
+.. opcode:: FSEQ - Float Set On Equal (ordered)
+
+ Same comparison as SEQ but returns integer instead of 1.0/0.0 float
+
+.. math::
+
+ dst.x = (src0.x == src1.x) ? \sim 0 : 0
+
+ dst.y = (src0.y == src1.y) ? \sim 0 : 0
+
+ dst.z = (src0.z == src1.z) ? \sim 0 : 0
+
+ dst.w = (src0.w == src1.w) ? \sim 0 : 0
+
+
+.. opcode:: USEQ - Integer Set On Equal
+
+.. math::
+
+ dst.x = (src0.x == src1.x) ? \sim 0 : 0
+
+ dst.y = (src0.y == src1.y) ? \sim 0 : 0
+
+ dst.z = (src0.z == src1.z) ? \sim 0 : 0
+
+ dst.w = (src0.w == src1.w) ? \sim 0 : 0
+
+
+.. opcode:: FSNE - Float Set On Not Equal (unordered)
+
+ Same comparison as SNE but returns integer instead of 1.0/0.0 float
+
+.. math::
+
+ dst.x = (src0.x != src1.x) ? \sim 0 : 0
+
+ dst.y = (src0.y != src1.y) ? \sim 0 : 0
+
+ dst.z = (src0.z != src1.z) ? \sim 0 : 0
+
+ dst.w = (src0.w != src1.w) ? \sim 0 : 0
+
+
+.. opcode:: USNE - Integer Set On Not Equal
+
+.. math::
+
+ dst.x = (src0.x != src1.x) ? \sim 0 : 0
+
+ dst.y = (src0.y != src1.y) ? \sim 0 : 0
+
+ dst.z = (src0.z != src1.z) ? \sim 0 : 0
+
+ dst.w = (src0.w != src1.w) ? \sim 0 : 0
+
+
+.. opcode:: INEG - Integer Negate
+
+ Two's complement.
+
+.. math::
+
+ dst.x = -src.x
+
+ dst.y = -src.y
+
+ dst.z = -src.z
+
+ dst.w = -src.w
+
+
+.. opcode:: IABS - Integer Absolute Value
+
+.. math::
+
+ dst.x = |src.x|
+
+ dst.y = |src.y|
+
+ dst.z = |src.z|
+
+ dst.w = |src.w|
+
+Bitwise ISA
+^^^^^^^^^^^
+These opcodes are used for bit-level manipulation of integers.
+
+.. opcode:: IBFE - Signed Bitfield Extract
+
+ See SM5 instruction of the same name. Extracts a set of bits from the input,
+ and sign-extends them if the high bit of the extracted window is set.
+
+ Pseudocode::
+
+ def ibfe(value, offset, bits):
+ offset = offset & 0x1f
+ bits = bits & 0x1f
+ if bits == 0: return 0
+ # Note: >> sign-extends
+ if width + offset < 32:
+ return (value << (32 - offset - bits)) >> (32 - bits)
+ else:
+ return value >> offset
+
+.. opcode:: UBFE - Unsigned Bitfield Extract
+
+ See SM5 instruction of the same name. Extracts a set of bits from the input,
+ without any sign-extension.
+
+ Pseudocode::
+
+ def ubfe(value, offset, bits):
+ offset = offset & 0x1f
+ bits = bits & 0x1f
+ if bits == 0: return 0
+ # Note: >> does not sign-extend
+ if width + offset < 32:
+ return (value << (32 - offset - bits)) >> (32 - bits)
+ else:
+ return value >> offset
+
+.. opcode:: BFI - Bitfield Insert
+
+ See SM5 instruction of the same name. Replaces a bit region of 'base' with
+ the low bits of 'insert'.
+
+ Pseudocode::
+
+ def bfi(base, insert, offset, bits):
+ offset = offset & 0x1f
+ bits = bits & 0x1f
+ mask = ((1 << bits) - 1) << offset
+ return ((insert << offset) & mask) | (base & ~mask)
+
+.. opcode:: BREV - Bitfield Reverse
+
+ See SM5 instruction BFREV. Reverses the bits of the argument.
+
+.. opcode:: POPC - Population Count
+
+ See SM5 instruction COUNTBITS. Counts the number of set bits in the argument.
+
+.. opcode:: LSB - Index of lowest set bit
+
+ See SM5 instruction FIRSTBIT_LO. Computes the 0-based index of the first set
+ bit of the argument. Returns -1 if none are set.
+
+.. opcode:: IMSB - Index of highest non-sign bit
+
+ See SM5 instruction FIRSTBIT_SHI. Computes the 0-based index of the highest
+ non-sign bit of the argument (i.e. highest 0 bit for negative numbers,
+ highest 1 bit for positive numbers). Returns -1 if all bits are the same
+ (i.e. for inputs 0 and -1).
+
+.. opcode:: UMSB - Index of highest set bit
+
+ See SM5 instruction FIRSTBIT_HI. Computes the 0-based index of the highest
+ set bit of the argument. Returns -1 if none are set.
+
+Geometry ISA
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
These opcodes are only supported in geometry shaders; they have no meaning
in any other type of shader.
-.. opcode:: EMIT - Emit
+.. opcode:: EMIT - Emit
+
+ Generate a new vertex for the current primitive into the specified vertex
+ stream using the values in the output registers.
+
+
+.. opcode:: ENDPRIM - End Primitive
+
+ Complete the current primitive in the specified vertex stream (consisting of
+ the emitted vertices), and start a new one.
+
+
+GLSL ISA
+^^^^^^^^^^
+
+These opcodes are part of :term:`GLSL`'s opcode set. Support for these
+opcodes is determined by a special capability bit, ``GLSL``.
+Some require glsl version 1.30 (UIF/BREAKC/SWITCH/CASE/DEFAULT/ENDSWITCH).
+
+.. opcode:: CAL - Subroutine Call
+
+ push(pc)
+ pc = target
+
+
+.. opcode:: RET - Subroutine Call Return
+
+ pc = pop()
+
+
+.. opcode:: CONT - Continue
+
+ Unconditionally moves the point of execution to the instruction after the
+ last bgnloop. The instruction must appear within a bgnloop/endloop.
+
+.. note::
+
+ Support for CONT is determined by a special capability bit,
+ ``TGSI_CONT_SUPPORTED``. See :ref:`Screen` for more information.
+
+
+.. opcode:: BGNLOOP - Begin a Loop
+
+ Start a loop. Must have a matching endloop.
+
+
+.. opcode:: BGNSUB - Begin Subroutine
+
+ Starts definition of a subroutine. Must have a matching endsub.
+
+
+.. opcode:: ENDLOOP - End a Loop
+
+ End a loop started with bgnloop.
+
+
+.. opcode:: ENDSUB - End Subroutine
+
+ Ends definition of a subroutine.
+
+
+.. opcode:: NOP - No Operation
+
+ Do nothing.
+
+
+.. opcode:: BRK - Break
+
+ Unconditionally moves the point of execution to the instruction after the
+ next endloop or endswitch. The instruction must appear within a loop/endloop
+ or switch/endswitch.
+
+
+.. opcode:: BREAKC - Break Conditional
+
+ Conditionally moves the point of execution to the instruction after the
+ next endloop or endswitch. The instruction must appear within a loop/endloop
+ or switch/endswitch.
+ Condition evaluates to true if src0.x != 0 where src0.x is interpreted
+ as an integer register.
+
+.. note::
+
+ Considered for removal as it's quite inconsistent wrt other opcodes
+ (could emulate with UIF/BRK/ENDIF).
+
+
+.. opcode:: IF - Float If
+
+ Start an IF ... ELSE .. ENDIF block. Condition evaluates to true if
+
+ src0.x != 0.0
+
+ where src0.x is interpreted as a floating point register.
+
+
+.. opcode:: UIF - Bitwise If
+
+ Start an UIF ... ELSE .. ENDIF block. Condition evaluates to true if
+
+ src0.x != 0
+
+ where src0.x is interpreted as an integer register.
+
+
+.. opcode:: ELSE - Else
+
+ Starts an else block, after an IF or UIF statement.
+
+
+.. opcode:: ENDIF - End If
+
+ Ends an IF or UIF block.
+
+
+.. opcode:: SWITCH - Switch
+
+ Starts a C-style switch expression. The switch consists of one or multiple
+ CASE statements, and at most one DEFAULT statement. Execution of a statement
+ ends when a BRK is hit, but just like in C falling through to other cases
+ without a break is allowed. Similarly, DEFAULT label is allowed anywhere not
+ just as last statement, and fallthrough is allowed into/from it.
+ CASE src arguments are evaluated at bit level against the SWITCH src argument.
+
+ Example::
+
+ SWITCH src[0].x
+ CASE src[0].x
+ (some instructions here)
+ (optional BRK here)
+ DEFAULT
+ (some instructions here)
+ (optional BRK here)
+ CASE src[0].x
+ (some instructions here)
+ (optional BRK here)
+ ENDSWITCH
+
+
+.. opcode:: CASE - Switch case
+
+ This represents a switch case label. The src arg must be an integer immediate.
+
+
+.. opcode:: DEFAULT - Switch default
+
+ This represents the default case in the switch, which is taken if no other
+ case matches.
+
+
+.. opcode:: ENDSWITCH - End of switch
+
+ Ends a switch expression.
+
+
+Interpolation ISA
+^^^^^^^^^^^^^^^^^
+
+The interpolation instructions allow an input to be interpolated in a
+different way than its declaration. This corresponds to the GLSL 4.00
+interpolateAt* functions. The first argument of each of these must come from
+``TGSI_FILE_INPUT``.
+
+.. opcode:: INTERP_CENTROID - Interpolate at the centroid
+
+ Interpolates the varying specified by src0 at the centroid
+
+.. opcode:: INTERP_SAMPLE - Interpolate at the specified sample
+
+ Interpolates the varying specified by src0 at the sample id specified by
+ src1.x (interpreted as an integer)
+
+.. opcode:: INTERP_OFFSET - Interpolate at the specified offset
+
+ Interpolates the varying specified by src0 at the offset src1.xy from the
+ pixel center (interpreted as floats)
+
+
+.. _doubleopcodes:
+
+Double ISA
+^^^^^^^^^^^^^^^
+
+The double-precision opcodes reinterpret four-component vectors into
+two-component vectors with doubled precision in each component.
+
+.. opcode:: DABS - Absolute
+
+ dst.xy = |src0.xy|
+ dst.zw = |src0.zw|
+
+.. opcode:: DADD - Add
+
+.. math::
+
+ dst.xy = src0.xy + src1.xy
+
+ dst.zw = src0.zw + src1.zw
+
+.. opcode:: DSEQ - Set on Equal
+
+.. math::
+
+ dst.x = src0.xy == src1.xy ? \sim 0 : 0
+
+ dst.z = src0.zw == src1.zw ? \sim 0 : 0
+
+.. opcode:: DSNE - Set on Equal
+
+.. math::
+
+ dst.x = src0.xy != src1.xy ? \sim 0 : 0
+
+ dst.z = src0.zw != src1.zw ? \sim 0 : 0
+
+.. opcode:: DSLT - Set on Less than
+
+.. math::
+
+ dst.x = src0.xy < src1.xy ? \sim 0 : 0
+
+ dst.z = src0.zw < src1.zw ? \sim 0 : 0
+
+.. opcode:: DSGE - Set on Greater equal
+
+.. math::
+
+ dst.x = src0.xy >= src1.xy ? \sim 0 : 0
+
+ dst.z = src0.zw >= src1.zw ? \sim 0 : 0
+
+.. opcode:: DFRAC - Fraction
+
+.. math::
+
+ dst.xy = src.xy - \lfloor src.xy\rfloor
+
+ dst.zw = src.zw - \lfloor src.zw\rfloor
+
+.. opcode:: DTRUNC - Truncate
+
+.. math::
+
+ dst.xy = trunc(src.xy)
+
+ dst.zw = trunc(src.zw)
+
+.. opcode:: DCEIL - Ceiling
+
+.. math::
+
+ dst.xy = \lceil src.xy\rceil
+
+ dst.zw = \lceil src.zw\rceil
+
+.. opcode:: DFLR - Floor
+
+.. math::
+
+ dst.xy = \lfloor src.xy\rfloor
+
+ dst.zw = \lfloor src.zw\rfloor
+
+.. opcode:: DROUND - Fraction
+
+.. math::
+
+ dst.xy = round(src.xy)
+
+ dst.zw = round(src.zw)
+
+.. opcode:: DSSG - Set Sign
+
+.. math::
+
+ dst.xy = (src.xy > 0) ? 1.0 : (src.xy < 0) ? -1.0 : 0.0
+
+ dst.zw = (src.zw > 0) ? 1.0 : (src.zw < 0) ? -1.0 : 0.0
+
+.. 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 = exp(src.xy)
+
+ dst1.xy = frac(src.xy)
+
+ 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`. The second
+source is an integer.
+
+.. math::
+
+ dst.xy = src0.xy \times 2^{src1.x}
+
+ dst.zw = src0.zw \times 2^{src1.y}
+
+.. opcode:: DMIN - Minimum
+
+.. math::
+
+ dst.xy = min(src0.xy, src1.xy)
+
+ dst.zw = min(src0.zw, src1.zw)
+
+.. opcode:: DMAX - Maximum
+
+.. math::
+
+ dst.xy = max(src0.xy, src1.xy)
+
+ dst.zw = max(src0.zw, src1.zw)
+
+.. opcode:: DMUL - Multiply
+
+.. math::
+
+ dst.xy = src0.xy \times src1.xy
+
+ dst.zw = src0.zw \times src1.zw
+
+
+.. opcode:: DMAD - Multiply And Add
+
+.. math::
+
+ dst.xy = src0.xy \times src1.xy + src2.xy
+
+ dst.zw = src0.zw \times src1.zw + src2.zw
+
+
+.. opcode:: DFMA - Fused Multiply-Add
+
+Perform a * b + c with no intermediate rounding step.
+
+.. math::
+
+ dst.xy = src0.xy \times src1.xy + src2.xy
+
+ dst.zw = src0.zw \times src1.zw + src2.zw
+
+
+.. opcode:: DRCP - Reciprocal
+
+.. math::
+
+ dst.xy = \frac{1}{src.xy}
+
+ dst.zw = \frac{1}{src.zw}
+
+.. opcode:: DSQRT - Square Root
+
+.. math::
+
+ dst.xy = \sqrt{src.xy}
+
+ dst.zw = \sqrt{src.zw}
+
+.. opcode:: DRSQ - Reciprocal Square Root
+
+.. math::
+
+ dst.xy = \frac{1}{\sqrt{src.xy}}
+
+ dst.zw = \frac{1}{\sqrt{src.zw}}
+
+.. opcode:: F2D - Float to Double
+
+.. math::
+
+ dst.xy = double(src0.x)
+
+ dst.zw = double(src0.y)
+
+.. opcode:: D2F - Double to Float
+
+.. math::
+
+ dst.x = float(src0.xy)
+
+ dst.y = float(src0.zw)
+
+.. opcode:: I2D - Int to Double
+
+.. math::
+
+ dst.xy = double(src0.x)
+
+ dst.zw = double(src0.y)
+
+.. opcode:: D2I - Double to Int
- TBD
+.. math::
+ dst.x = int(src0.xy)
-.. opcode:: ENDPRIM - End Primitive
+ dst.y = int(src0.zw)
- TBD
+.. opcode:: U2D - Unsigned Int to Double
+.. math::
-GLSL ISA
-^^^^^^^^^^
+ dst.xy = double(src0.x)
-These opcodes are part of :term:`GLSL`'s opcode set. Support for these
-opcodes is determined by a special capability bit, ``GLSL``.
+ dst.zw = double(src0.y)
-.. opcode:: BGNLOOP - Begin a Loop
+.. opcode:: D2U - Double to Unsigned Int
- TBD
+.. math::
+ dst.x = unsigned(src0.xy)
-.. opcode:: BGNSUB - Begin Subroutine
+ dst.y = unsigned(src0.zw)
- TBD
+.. _samplingopcodes:
+Resource Sampling Opcodes
+^^^^^^^^^^^^^^^^^^^^^^^^^
-.. opcode:: ENDLOOP - End a Loop
+Those opcodes follow very closely semantics of the respective Direct3D
+instructions. If in doubt double check Direct3D documentation.
+Note that the swizzle on SVIEW (src1) determines texel swizzling
+after lookup.
- TBD
+.. opcode:: SAMPLE
+ Using provided address, sample data from the specified texture using the
+ filtering mode identified by the gven sampler. The source data may come from
+ any resource type other than buffers.
-.. opcode:: ENDSUB - End Subroutine
+ Syntax: ``SAMPLE dst, address, sampler_view, sampler``
- TBD
+ Example: ``SAMPLE TEMP[0], TEMP[1], SVIEW[0], SAMP[0]``
+.. opcode:: SAMPLE_I
-.. opcode:: NOP - No Operation
+ Simplified alternative to the SAMPLE instruction. Using the provided
+ integer address, SAMPLE_I fetches data from the specified sampler view
+ without any filtering. The source data may come from any resource type
+ other than CUBE.
- Do nothing.
+ Syntax: ``SAMPLE_I dst, address, sampler_view``
+ Example: ``SAMPLE_I TEMP[0], TEMP[1], SVIEW[0]``
-.. opcode:: NRM4 - 4-component Vector Normalise
+ The 'address' is specified as unsigned integers. If the 'address' is out of
+ range [0...(# texels - 1)] the result of the fetch is always 0 in all
+ components. As such the instruction doesn't honor address wrap modes, in
+ cases where that behavior is desirable 'SAMPLE' instruction should be used.
+ address.w always provides an unsigned integer mipmap level. If the value is
+ out of the range then the instruction always returns 0 in all components.
+ address.yz are ignored for buffers and 1d textures. address.z is ignored
+ for 1d texture arrays and 2d textures.
-This instruction replicates its result.
+ For 1D texture arrays address.y provides the array index (also as unsigned
+ integer). If the value is out of the range of available array indices
+ [0... (array size - 1)] then the opcode always returns 0 in all components.
+ For 2D texture arrays address.z provides the array index, otherwise it
+ exhibits the same behavior as in the case for 1D texture arrays. The exact
+ semantics of the source address are presented in the table below:
-.. math::
+ +---------------------------+----+-----+-----+---------+
+ | resource type | X | Y | Z | W |
+ +===========================+====+=====+=====+=========+
+ | ``PIPE_BUFFER`` | x | | | ignored |
+ +---------------------------+----+-----+-----+---------+
+ | ``PIPE_TEXTURE_1D`` | x | | | mpl |
+ +---------------------------+----+-----+-----+---------+
+ | ``PIPE_TEXTURE_2D`` | x | y | | mpl |
+ +---------------------------+----+-----+-----+---------+
+ | ``PIPE_TEXTURE_3D`` | x | y | z | mpl |
+ +---------------------------+----+-----+-----+---------+
+ | ``PIPE_TEXTURE_RECT`` | x | y | | mpl |
+ +---------------------------+----+-----+-----+---------+
+ | ``PIPE_TEXTURE_CUBE`` | not allowed as source |
+ +---------------------------+----+-----+-----+---------+
+ | ``PIPE_TEXTURE_1D_ARRAY`` | x | idx | | mpl |
+ +---------------------------+----+-----+-----+---------+
+ | ``PIPE_TEXTURE_2D_ARRAY`` | x | y | idx | mpl |
+ +---------------------------+----+-----+-----+---------+
- dst = \frac{src.x}{src.x \times src.x + src.y \times src.y + src.z \times src.z + src.w \times src.w}
+ Where 'mpl' is a mipmap level and 'idx' is the array index.
+.. opcode:: SAMPLE_I_MS
-ps_2_x
-^^^^^^^^^^^^
+ Just like SAMPLE_I but allows fetch data from multi-sampled surfaces.
-XXX wait what
+ Syntax: ``SAMPLE_I_MS dst, address, sampler_view, sample``
-.. opcode:: CALLNZ - Subroutine Call If Not Zero
+.. opcode:: SAMPLE_B
- TBD
+ Just like the SAMPLE instruction with the exception that an additional bias
+ is applied to the level of detail computed as part of the instruction
+ execution.
+ Syntax: ``SAMPLE_B dst, address, sampler_view, sampler, lod_bias``
-.. opcode:: IFC - If
+ Example: ``SAMPLE_B TEMP[0], TEMP[1], SVIEW[0], SAMP[0], TEMP[2].x``
- TBD
+.. opcode:: SAMPLE_C
+ Similar to the SAMPLE instruction but it performs a comparison filter. The
+ operands to SAMPLE_C are identical to SAMPLE, except that there is an
+ additional float32 operand, reference value, which must be a register with
+ single-component, or a scalar literal. SAMPLE_C makes the hardware use the
+ current samplers compare_func (in pipe_sampler_state) to compare reference
+ value against the red component value for the surce resource at each texel
+ that the currently configured texture filter covers based on the provided
+ coordinates.
-.. opcode:: BREAKC - Break Conditional
+ Syntax: ``SAMPLE_C dst, address, sampler_view.r, sampler, ref_value``
- TBD
+ Example: ``SAMPLE_C TEMP[0], TEMP[1], SVIEW[0].r, SAMP[0], TEMP[2].x``
-.. _doubleopcodes:
+.. opcode:: SAMPLE_C_LZ
-Double ISA
-^^^^^^^^^^^^^^^
+ Same as SAMPLE_C, but LOD is 0 and derivatives are ignored. The LZ stands
+ for level-zero.
-The double-precision opcodes reinterpret four-component vectors into
-two-component vectors with doubled precision in each component.
+ Syntax: ``SAMPLE_C_LZ dst, address, sampler_view.r, sampler, ref_value``
-Support for these opcodes is XXX undecided. :T
+ Example: ``SAMPLE_C_LZ TEMP[0], TEMP[1], SVIEW[0].r, SAMP[0], TEMP[2].x``
-.. opcode:: DADD - Add
-.. math::
+.. opcode:: SAMPLE_D
- dst.xy = src0.xy + src1.xy
+ SAMPLE_D is identical to the SAMPLE opcode except that the derivatives for
+ the source address in the x direction and the y direction are provided by
+ extra parameters.
- dst.zw = src0.zw + src1.zw
+ Syntax: ``SAMPLE_D dst, address, sampler_view, sampler, der_x, der_y``
+ Example: ``SAMPLE_D TEMP[0], TEMP[1], SVIEW[0], SAMP[0], TEMP[2], TEMP[3]``
-.. opcode:: DDIV - Divide
+.. opcode:: SAMPLE_L
-.. math::
+ SAMPLE_L is identical to the SAMPLE opcode except that the LOD is provided
+ directly as a scalar value, representing no anisotropy.
- dst.xy = src0.xy / src1.xy
+ Syntax: ``SAMPLE_L dst, address, sampler_view, sampler, explicit_lod``
- dst.zw = src0.zw / src1.zw
+ Example: ``SAMPLE_L TEMP[0], TEMP[1], SVIEW[0], SAMP[0], TEMP[2].x``
-.. opcode:: DSEQ - Set on Equal
+.. opcode:: GATHER4
-.. math::
+ Gathers the four texels to be used in a bi-linear filtering operation and
+ packs them into a single register. Only works with 2D, 2D array, cubemaps,
+ and cubemaps arrays. For 2D textures, only the addressing modes of the
+ sampler and the top level of any mip pyramid are used. Set W to zero. It
+ behaves like the SAMPLE instruction, but a filtered sample is not
+ generated. The four samples that contribute to filtering are placed into
+ xyzw in counter-clockwise order, starting with the (u,v) texture coordinate
+ delta at the following locations (-, +), (+, +), (+, -), (-, -), where the
+ magnitude of the deltas are half a texel.
- dst.xy = src0.xy == src1.xy ? 1.0F : 0.0F
- dst.zw = src0.zw == src1.zw ? 1.0F : 0.0F
+.. opcode:: SVIEWINFO
-.. opcode:: DSLT - Set on Less than
+ Query the dimensions of a given sampler view. dst receives width, height,
+ depth or array size and number of mipmap levels as int4. The dst can have a
+ writemask which will specify what info is the caller interested in.
+
+ Syntax: ``SVIEWINFO dst, src_mip_level, sampler_view``
+
+ Example: ``SVIEWINFO TEMP[0], TEMP[1].x, SVIEW[0]``
+
+ src_mip_level is an unsigned integer scalar. If it's out of range then
+ returns 0 for width, height and depth/array size but the total number of
+ mipmap is still returned correctly for the given sampler view. The returned
+ width, height and depth values are for the mipmap level selected by the
+ src_mip_level and are in the number of texels. For 1d texture array width
+ is in dst.x, array size is in dst.y and dst.z is 0. The number of mipmaps is
+ still in dst.w. In contrast to d3d10 resinfo, there's no way in the tgsi
+ instruction encoding to specify the return type (float/rcpfloat/uint), hence
+ always using uint. Also, unlike the SAMPLE instructions, the swizzle on src1
+ resinfo allowing swizzling dst values is ignored (due to the interaction
+ with rcpfloat modifier which requires some swizzle handling in the state
+ tracker anyway).
+
+.. opcode:: SAMPLE_POS
+
+ Query the position of a given sample. dst receives float4 (x, y, 0, 0)
+ indicated where the sample is located. If the resource is not a multi-sample
+ resource and not a render target, the result is 0.
+
+.. opcode:: SAMPLE_INFO
+
+ dst receives number of samples in x. If the resource is not a multi-sample
+ resource and not a render target, the result is 0.
+
+
+.. _resourceopcodes:
+
+Resource Access Opcodes
+^^^^^^^^^^^^^^^^^^^^^^^
+
+.. opcode:: LOAD - Fetch data from a shader resource
+
+ Syntax: ``LOAD dst, resource, address``
+
+ Example: ``LOAD TEMP[0], RES[0], TEMP[1]``
+
+ Using the provided integer address, LOAD fetches data
+ from the specified buffer or texture without any
+ filtering.
+
+ The 'address' is specified as a vector of unsigned
+ integers. If the 'address' is out of range the result
+ is unspecified.
+
+ Only the first mipmap level of a resource can be read
+ from using this instruction.
+
+ For 1D or 2D texture arrays, the array index is
+ provided as an unsigned integer in address.y or
+ address.z, respectively. address.yz are ignored for
+ buffers and 1D textures. address.z is ignored for 1D
+ texture arrays and 2D textures. address.w is always
+ ignored.
+
+.. opcode:: STORE - Write data to a shader resource
+
+ Syntax: ``STORE resource, address, src``
+
+ Example: ``STORE RES[0], TEMP[0], TEMP[1]``
+
+ Using the provided integer address, STORE writes data
+ to the specified buffer or texture.
+
+ The 'address' is specified as a vector of unsigned
+ integers. If the 'address' is out of range the result
+ is unspecified.
+
+ Only the first mipmap level of a resource can be
+ written to using this instruction.
+
+ For 1D or 2D texture arrays, the array index is
+ provided as an unsigned integer in address.y or
+ address.z, respectively. address.yz are ignored for
+ buffers and 1D textures. address.z is ignored for 1D
+ texture arrays and 2D textures. address.w is always
+ ignored.
+
+
+.. _threadsyncopcodes:
+
+Inter-thread synchronization opcodes
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+These opcodes are intended for communication between threads running
+within the same compute grid. For now they're only valid in compute
+programs.
+
+.. opcode:: MFENCE - Memory fence
+
+ Syntax: ``MFENCE resource``
+
+ Example: ``MFENCE RES[0]``
+
+ This opcode forces strong ordering between any memory access
+ operations that affect the specified resource. This means that
+ previous loads and stores (and only those) will be performed and
+ visible to other threads before the program execution continues.
+
+
+.. opcode:: LFENCE - Load memory fence
+
+ Syntax: ``LFENCE resource``
+
+ Example: ``LFENCE RES[0]``
+
+ Similar to MFENCE, but it only affects the ordering of memory loads.
+
+
+.. opcode:: SFENCE - Store memory fence
+
+ Syntax: ``SFENCE resource``
+
+ Example: ``SFENCE RES[0]``
+
+ Similar to MFENCE, but it only affects the ordering of memory stores.
+
+
+.. opcode:: BARRIER - Thread group barrier
+
+ ``BARRIER``
+
+ This opcode suspends the execution of the current thread until all
+ the remaining threads in the working group reach the same point of
+ the program. Results are unspecified if any of the remaining
+ threads terminates or never reaches an executed BARRIER instruction.
+
+
+.. _atomopcodes:
+
+Atomic opcodes
+^^^^^^^^^^^^^^
+
+These opcodes provide atomic variants of some common arithmetic and
+logical operations. In this context atomicity means that another
+concurrent memory access operation that affects the same memory
+location is guaranteed to be performed strictly before or after the
+entire execution of the atomic operation.
+
+For the moment they're only valid in compute programs.
+
+.. opcode:: ATOMUADD - Atomic integer addition
+
+ Syntax: ``ATOMUADD dst, resource, offset, src``
+
+ Example: ``ATOMUADD TEMP[0], RES[0], TEMP[1], TEMP[2]``
+
+ The following operation is performed atomically on each component:
.. math::
- dst.xy = src0.xy < src1.xy ? 1.0F : 0.0F
+ dst_i = resource[offset]_i
- dst.zw = src0.zw < src1.zw ? 1.0F : 0.0F
+ resource[offset]_i = dst_i + src_i
-.. opcode:: DFRAC - Fraction
+
+.. opcode:: ATOMXCHG - Atomic exchange
+
+ Syntax: ``ATOMXCHG dst, resource, offset, src``
+
+ Example: ``ATOMXCHG TEMP[0], RES[0], TEMP[1], TEMP[2]``
+
+ The following operation is performed atomically on each component:
.. math::
- dst.xy = src.xy - \lfloor src.xy\rfloor
+ dst_i = resource[offset]_i
- dst.zw = src.zw - \lfloor src.zw\rfloor
+ resource[offset]_i = src_i
-.. opcode:: DFRACEXP - Convert Number to Fractional and Integral Components
+.. opcode:: ATOMCAS - Atomic compare-and-exchange
-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` .
+ Syntax: ``ATOMCAS dst, resource, offset, cmp, src``
+
+ Example: ``ATOMCAS TEMP[0], RES[0], TEMP[1], TEMP[2], TEMP[3]``
+
+ The following operation is performed atomically on each component:
.. math::
- dst0.xy = exp(src.xy)
+ dst_i = resource[offset]_i
- dst1.xy = frac(src.xy)
+ resource[offset]_i = (dst_i == cmp_i ? src_i : dst_i)
- dst0.zw = exp(src.zw)
- dst1.zw = frac(src.zw)
+.. opcode:: ATOMAND - Atomic bitwise And
-.. opcode:: DLDEXP - Multiply Number by Integral Power of 2
+ Syntax: ``ATOMAND dst, resource, offset, src``
-This opcode is the inverse of :opcode:`DFRACEXP`.
+ Example: ``ATOMAND TEMP[0], RES[0], TEMP[1], TEMP[2]``
+
+ The following operation is performed atomically on each component:
.. math::
- dst.xy = src0.xy \times 2^{src1.xy}
+ dst_i = resource[offset]_i
- dst.zw = src0.zw \times 2^{src1.zw}
+ resource[offset]_i = dst_i \& src_i
-.. opcode:: DMIN - Minimum
+
+.. opcode:: ATOMOR - Atomic bitwise Or
+
+ Syntax: ``ATOMOR dst, resource, offset, src``
+
+ Example: ``ATOMOR TEMP[0], RES[0], TEMP[1], TEMP[2]``
+
+ The following operation is performed atomically on each component:
.. math::
- dst.xy = min(src0.xy, src1.xy)
+ dst_i = resource[offset]_i
- dst.zw = min(src0.zw, src1.zw)
+ resource[offset]_i = dst_i | src_i
-.. opcode:: DMAX - Maximum
+
+.. opcode:: ATOMXOR - Atomic bitwise Xor
+
+ Syntax: ``ATOMXOR dst, resource, offset, src``
+
+ Example: ``ATOMXOR TEMP[0], RES[0], TEMP[1], TEMP[2]``
+
+ The following operation is performed atomically on each component:
.. math::
- dst.xy = max(src0.xy, src1.xy)
+ dst_i = resource[offset]_i
- dst.zw = max(src0.zw, src1.zw)
+ resource[offset]_i = dst_i \oplus src_i
-.. opcode:: DMUL - Multiply
+
+.. opcode:: ATOMUMIN - Atomic unsigned minimum
+
+ Syntax: ``ATOMUMIN dst, resource, offset, src``
+
+ Example: ``ATOMUMIN TEMP[0], RES[0], TEMP[1], TEMP[2]``
+
+ The following operation is performed atomically on each component:
.. math::
- dst.xy = src0.xy \times src1.xy
+ dst_i = resource[offset]_i
- dst.zw = src0.zw \times src1.zw
+ resource[offset]_i = (dst_i < src_i ? dst_i : src_i)
-.. opcode:: DMAD - Multiply And Add
+.. opcode:: ATOMUMAX - Atomic unsigned maximum
+
+ Syntax: ``ATOMUMAX dst, resource, offset, src``
+
+ Example: ``ATOMUMAX TEMP[0], RES[0], TEMP[1], TEMP[2]``
+
+ The following operation is performed atomically on each component:
.. math::
- dst.xy = src0.xy \times src1.xy + src2.xy
+ dst_i = resource[offset]_i
- dst.zw = src0.zw \times src1.zw + src2.zw
+ resource[offset]_i = (dst_i > src_i ? dst_i : src_i)
-.. opcode:: DRCP - Reciprocal
+.. opcode:: ATOMIMIN - Atomic signed minimum
+
+ Syntax: ``ATOMIMIN dst, resource, offset, src``
+
+ Example: ``ATOMIMIN TEMP[0], RES[0], TEMP[1], TEMP[2]``
+
+ The following operation is performed atomically on each component:
.. math::
- dst.xy = \frac{1}{src.xy}
+ dst_i = resource[offset]_i
- dst.zw = \frac{1}{src.zw}
+ resource[offset]_i = (dst_i < src_i ? dst_i : src_i)
-.. opcode:: DSQRT - Square Root
+
+.. opcode:: ATOMIMAX - Atomic signed maximum
+
+ Syntax: ``ATOMIMAX dst, resource, offset, src``
+
+ Example: ``ATOMIMAX TEMP[0], RES[0], TEMP[1], TEMP[2]``
+
+ The following operation is performed atomically on each component:
.. math::
- dst.xy = \sqrt{src.xy}
+ dst_i = resource[offset]_i
+
+ resource[offset]_i = (dst_i > src_i ? dst_i : src_i)
- dst.zw = \sqrt{src.zw}
Explanation of symbols used
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.
+The Local flag specifies that a given value isn't intended for
+subroutine parameter passing and, as a result, the implementation
+isn't required to give any guarantees of it being preserved across
+subroutine boundaries. As it's merely a compiler hint, the
+implementation is free to ignore it.
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.
+If Interpolate flag is set to 1, a Declaration Interpolate token follows.
+
+If file is TGSI_FILE_RESOURCE, a Declaration Resource token follows.
+
+If Array flag is set to 1, a Declaration Array token follows.
+Array Declaration
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+Declarations can optional have an ArrayID attribute which can be referred by
+indirect addressing operands. An ArrayID of zero is reserved and treated as
+if no ArrayID is specified.
+
+If an indirect addressing operand refers to a specific declaration by using
+an ArrayID only the registers in this declaration are guaranteed to be
+accessed, accessing any register outside this declaration results in undefined
+behavior. Note that for compatibility the effective index is zero-based and
+not relative to the specified declaration
+
+If no ArrayID is specified with an indirect addressing operand the whole
+register file might be accessed by this operand. This is strongly discouraged
+and will prevent packing of scalar/vec2 arrays and effective alias analysis.
+This is only legal for TEMP and CONST register files.
Declaration Semantic
^^^^^^^^^^^^^^^^^^^^^^^^
- Vertex and fragment shader input and output registers may be labeled
- with semantic information consisting of a name and index.
+Vertex and fragment shader input and output registers may be labeled
+with semantic information consisting of a name and index.
- Follows Declaration token if Semantic bit is set.
+Follows Declaration token if Semantic bit is set.
- Since its purpose is to link a shader with other stages of the pipeline,
- it is valid to follow only those Declaration tokens that declare a register
- either in INPUT or OUTPUT file.
+Since its purpose is to link a shader with other stages of the pipeline,
+it is valid to follow only those Declaration tokens that declare a register
+either in INPUT or OUTPUT file.
- SemanticName field contains the semantic name of the register being declared.
- There is no default value.
+SemanticName field contains the semantic name of the register being declared.
+There is no default value.
- SemanticIndex is an optional subscript that can be used to distinguish
- different register declarations with the same semantic name. The default value
- is 0.
+SemanticIndex is an optional subscript that can be used to distinguish
+different register declarations with the same semantic name. The default value
+is 0.
- The meanings of the individual semantic names are explained in the following
- sections.
+The meanings of the individual semantic names are explained in the following
+sections.
TGSI_SEMANTIC_POSITION
""""""""""""""""""""""
indicate the top of the window or the bottom depending on the fragment
coordinate origin convention (see TGSI_PROPERTY_FS_COORD_ORIGIN).
The Z coordinate ranges from 0 to 1 to represent depth from the front
-to the back of the Z buffer. The W component contains the reciprocol
-of the interpolated vertex position W component.
+to the back of the Z buffer. The W component contains the interpolated
+reciprocal of the vertex position W component (corresponding to gl_Fragcoord,
+but unlike d3d10 which interpolates the same 1/w but then gives back
+the reciprocal of the interpolated value).
Fragment shaders may also declare an output register with
TGSI_SEMANTIC_POSITION. Only the Z component is writable. This allows
Vertex shader inputs and outputs and fragment shader inputs may be
labeled with TGSI_SEMANTIC_FOG to indicate that the register contains
-a fog coordinate in the form (F, 0, 0, 1). Typically, the fragment
-shader will use the fog coordinate to compute a fog blend factor which
-is used to blend the normal fragment color with a constant fog color.
-
-Only the first component matters when writing from the vertex shader;
-the driver will ensure that the coordinate is in this format when used
-as a fragment shader input.
+a fog coordinate. Typically, the fragment shader will use the fog coordinate
+to compute a fog blend factor which is used to blend the normal fragment color
+with a constant fog color. But fog coord really is just an ordinary vec4
+register like regular semantics.
TGSI_SEMANTIC_PSIZE
:ref:`rasterizer` first.
+TGSI_SEMANTIC_TEXCOORD
+""""""""""""""""""""""
+
+Only available if PIPE_CAP_TGSI_TEXCOORD is exposed !
+
+Vertex shader outputs and fragment shader inputs may be labeled with
+this semantic to make them replaceable by sprite coordinates via the
+sprite_coord_enable state in the :ref:`rasterizer`.
+The semantic index permitted with this semantic is limited to <= 7.
+
+If the driver does not support TEXCOORD, sprite coordinate replacement
+applies to inputs with the GENERIC semantic instead.
+
+The intended use case for this semantic is gl_TexCoord.
+
+
+TGSI_SEMANTIC_PCOORD
+""""""""""""""""""""
+
+Only available if PIPE_CAP_TGSI_TEXCOORD is exposed !
+
+Fragment shader inputs may be labeled with TGSI_SEMANTIC_PCOORD to indicate
+that the register contains sprite coordinates in the form (x, y, 0, 1), if
+the current primitive is a point and point sprites are enabled. Otherwise,
+the contents of the register are undefined.
+
+The intended use case for this semantic is gl_PointCoord.
+
+
TGSI_SEMANTIC_GENERIC
"""""""""""""""""""""
drawn when the polygon mode converts triangles/quads/polygons into
points or lines.
+
TGSI_SEMANTIC_STENCIL
-""""""""""""""""""""""
+"""""""""""""""""""""
-For fragment shaders, this semantic label indicates than an output
+For fragment shaders, this semantic label indicates that an output
is a writable stencil reference value. Only the Y component is writable.
This allows the fragment shader to change the fragments stencilref value.
-Properties
+TGSI_SEMANTIC_VIEWPORT_INDEX
+""""""""""""""""""""""""""""
+
+For geometry shaders, this semantic label indicates that an output
+contains the index of the viewport (and scissor) to use.
+This is an integer value, and only the X component is used.
+
+
+TGSI_SEMANTIC_LAYER
+"""""""""""""""""""
+
+For geometry shaders, this semantic label indicates that an output
+contains the layer value to use for the color and depth/stencil surfaces.
+This is an integer value, and only the X component is used.
+(Also known as rendertarget array index.)
+
+
+TGSI_SEMANTIC_CULLDIST
+""""""""""""""""""""""
+
+Used as distance to plane for performing application-defined culling
+of individual primitives against a plane. When components of vertex
+elements are given this label, these values are assumed to be a
+float32 signed distance to a plane. Primitives will be completely
+discarded if the plane distance for all of the vertices in the
+primitive are < 0. If a vertex has a cull distance of NaN, that
+vertex counts as "out" (as if its < 0);
+The limits on both clip and cull distances are bound
+by the PIPE_MAX_CLIP_OR_CULL_DISTANCE_COUNT define which defines
+the maximum number of components that can be used to hold the
+distances and by the PIPE_MAX_CLIP_OR_CULL_DISTANCE_ELEMENT_COUNT
+which specifies the maximum number of registers which can be
+annotated with those semantics.
+
+
+TGSI_SEMANTIC_CLIPDIST
+""""""""""""""""""""""
+
+When components of vertex elements are identified this way, these
+values are each assumed to be a float32 signed distance to a plane.
+Primitive setup only invokes rasterization on pixels for which
+the interpolated plane distances are >= 0. Multiple clip planes
+can be implemented simultaneously, by annotating multiple
+components of one or more vertex elements with the above specified
+semantic. The limits on both clip and cull distances are bound
+by the PIPE_MAX_CLIP_OR_CULL_DISTANCE_COUNT define which defines
+the maximum number of components that can be used to hold the
+distances and by the PIPE_MAX_CLIP_OR_CULL_DISTANCE_ELEMENT_COUNT
+which specifies the maximum number of registers which can be
+annotated with those semantics.
+
+TGSI_SEMANTIC_SAMPLEID
+""""""""""""""""""""""
+
+For fragment shaders, this semantic label indicates that a system value
+contains the current sample id (i.e. gl_SampleID).
+This is an integer value, and only the X component is used.
+
+TGSI_SEMANTIC_SAMPLEPOS
+"""""""""""""""""""""""
+
+For fragment shaders, this semantic label indicates that a system value
+contains the current sample's position (i.e. gl_SamplePosition). Only the X
+and Y values are used.
+
+TGSI_SEMANTIC_SAMPLEMASK
+""""""""""""""""""""""""
+
+For fragment shaders, this semantic label indicates that an output contains
+the sample mask used to disable further sample processing
+(i.e. gl_SampleMask). Only the X value is used, up to 32x MS.
+
+TGSI_SEMANTIC_INVOCATIONID
+""""""""""""""""""""""""""
+
+For geometry shaders, this semantic label indicates that a system value
+contains the current invocation id (i.e. gl_InvocationID).
+This is an integer value, and only the X component is used.
+
+TGSI_SEMANTIC_INSTANCEID
+""""""""""""""""""""""""
+
+For vertex shaders, this semantic label indicates that a system value contains
+the current instance id (i.e. gl_InstanceID). It does not include the base
+instance. This is an integer value, and only the X component is used.
+
+TGSI_SEMANTIC_VERTEXID
+""""""""""""""""""""""
+
+For vertex shaders, this semantic label indicates that a system value contains
+the current vertex id (i.e. gl_VertexID). It does (unlike in d3d10) include the
+base vertex. This is an integer value, and only the X component is used.
+
+TGSI_SEMANTIC_VERTEXID_NOBASE
+"""""""""""""""""""""""""""""""
+
+For vertex shaders, this semantic label indicates that a system value contains
+the current vertex id without including the base vertex (this corresponds to
+d3d10 vertex id, so TGSI_SEMANTIC_VERTEXID_NOBASE + TGSI_SEMANTIC_BASEVERTEX
+== TGSI_SEMANTIC_VERTEXID). This is an integer value, and only the X component
+is used.
+
+TGSI_SEMANTIC_BASEVERTEX
+""""""""""""""""""""""""
+
+For vertex shaders, this semantic label indicates that a system value contains
+the base vertex (i.e. gl_BaseVertex). Note that for non-indexed draw calls,
+this contains the first (or start) value instead.
+This is an integer value, and only the X component is used.
+
+TGSI_SEMANTIC_PRIMID
+""""""""""""""""""""
+
+For geometry and fragment shaders, this semantic label indicates the value
+contains the primitive id (i.e. gl_PrimitiveID). This is an integer value,
+and only the X component is used.
+FIXME: This right now can be either a ordinary input or a system value...
+
+
+TGSI_SEMANTIC_PATCH
+"""""""""""""""""""
+
+For tessellation evaluation/control shaders, this semantic label indicates a
+generic per-patch attribute. Such semantics will not implicitly be per-vertex
+arrays.
+
+TGSI_SEMANTIC_TESSCOORD
+"""""""""""""""""""""""
+
+For tessellation evaluation shaders, this semantic label indicates the
+coordinates of the vertex being processed. This is available in XYZ; W is
+undefined.
+
+TGSI_SEMANTIC_TESSOUTER
+"""""""""""""""""""""""
+
+For tessellation evaluation/control shaders, this semantic label indicates the
+outer tessellation levels of the patch. Isoline tessellation will only have XY
+defined, triangle will have XYZ and quads will have XYZW defined. This
+corresponds to gl_TessLevelOuter.
+
+TGSI_SEMANTIC_TESSINNER
+"""""""""""""""""""""""
+
+For tessellation evaluation/control shaders, this semantic label indicates the
+inner tessellation levels of the patch. The X value is only defined for
+triangle tessellation, while quads will have XY defined. This is entirely
+undefined for isoline tessellation.
+
+TGSI_SEMANTIC_VERTICESIN
+""""""""""""""""""""""""
+
+For tessellation evaluation/control shaders, this semantic label indicates the
+number of vertices provided in the input patch. Only the X value is defined.
+
+
+Declaration Interpolate
+^^^^^^^^^^^^^^^^^^^^^^^
+
+This token is only valid for fragment shader INPUT declarations.
+
+The Interpolate field specifes the way input is being interpolated by
+the rasteriser and is one of TGSI_INTERPOLATE_*.
+
+The Location field specifies the location inside the pixel that the
+interpolation should be done at, one of ``TGSI_INTERPOLATE_LOC_*``. Note that
+when per-sample shading is enabled, the implementation may choose to
+interpolate at the sample irrespective of the Location field.
+
+The CylindricalWrap bitfield 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 Sampler View
^^^^^^^^^^^^^^^^^^^^^^^^
+Follows Declaration token if file is TGSI_FILE_SAMPLER_VIEW.
+
+DCL SVIEW[#], resource, type(s)
+
+Declares a shader input sampler view and assigns it to a SVIEW[#]
+register.
+
+resource can be one of BUFFER, 1D, 2D, 3D, 1DArray and 2DArray.
+
+type must be 1 or 4 entries (if specifying on a per-component
+level) out of UNORM, SNORM, SINT, UINT and FLOAT.
+
+For TEX\* style texture sample opcodes (as opposed to SAMPLE\* opcodes
+which take an explicit SVIEW[#] source register), there may be optionally
+SVIEW[#] declarations. In this case, the SVIEW index is implied by the
+SAMP index, and there must be a corresponding SVIEW[#] declaration for
+each SAMP[#] declaration. Drivers are free to ignore this if they wish.
+But note in particular that some drivers need to know the sampler type
+(float/int/unsigned) in order to generate the correct code, so cases
+where integer textures are sampled, SVIEW[#] declarations should be
+used.
+
+NOTE: It is NOT legal to mix SAMPLE\* style opcodes and TEX\* opcodes
+in the same shader.
- Properties are general directives that apply to the whole TGSI program.
+Declaration Resource
+^^^^^^^^^^^^^^^^^^^^
+
+Follows Declaration token if file is TGSI_FILE_RESOURCE.
+
+DCL RES[#], resource [, WR] [, RAW]
+
+Declares a shader input resource and assigns it to a RES[#]
+register.
+
+resource can be one of BUFFER, 1D, 2D, 3D, CUBE, 1DArray and
+2DArray.
+
+If the RAW keyword is not specified, the texture data will be
+subject to conversion, swizzling and scaling as required to yield
+the specified data type from the physical data format of the bound
+resource.
+
+If the RAW keyword is specified, no channel conversion will be
+performed: the values read for each of the channels (X,Y,Z,W) will
+correspond to consecutive words in the same order and format
+they're found in memory. No element-to-address conversion will be
+performed either: the value of the provided X coordinate will be
+interpreted in byte units instead of texel units. The result of
+accessing a misaligned address is undefined.
+
+Usage of the STORE opcode is only allowed if the WR (writable) flag
+is set.
+
+
+Properties
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+Properties are general directives that apply to the whole TGSI program.
FS_COORD_ORIGIN
"""""""""""""""
If INTEGER, the fractionary part of the position will be 0.0
Note that this does not affect the set of fragments generated by
-rasterization, which is instead controlled by gl_rasterization_rules in the
+rasterization, which is instead controlled by half_pixel_center in the
rasterizer.
OpenGL defaults to HALF_INTEGER, and is configurable with the
DirectX 9 uses INTEGER.
DirectX 10 uses HALF_INTEGER.
+FS_COLOR0_WRITES_ALL_CBUFS
+""""""""""""""""""""""""""
+Specifies that writes to the fragment shader color 0 are replicated to all
+bound cbufs. This facilitates OpenGL's fragColor output vs fragData[0] where
+fragData is directed to a single color buffer, but fragColor is broadcast.
+
+VS_PROHIBIT_UCPS
+""""""""""""""""""""""""""
+If this property is set on the program bound to the shader stage before the
+fragment shader, user clip planes should have no effect (be disabled) even if
+that shader does not write to any clip distance outputs and the rasterizer's
+clip_plane_enable is non-zero.
+This property is only supported by drivers that also support shader clip
+distance outputs.
+This is useful for APIs that don't have UCPs and where clip distances written
+by a shader cannot be disabled.
+
+GS_INVOCATIONS
+""""""""""""""
+
+Specifies the number of times a geometry shader should be executed for each
+input primitive. Each invocation will have a different
+TGSI_SEMANTIC_INVOCATIONID system value set. If not specified, assumed to
+be 1.
+
+VS_WINDOW_SPACE_POSITION
+""""""""""""""""""""""""""
+If this property is set on the vertex shader, the TGSI_SEMANTIC_POSITION output
+is assumed to contain window space coordinates.
+Division of X,Y,Z by W and the viewport transformation are disabled, and 1/W is
+directly taken from the 4-th component of the shader output.
+Naturally, clipping is not performed on window coordinates either.
+The effect of this property is undefined if a geometry or tessellation shader
+are in use.
+
+TCS_VERTICES_OUT
+""""""""""""""""
+
+The number of vertices written by the tessellation control shader. This
+effectively defines the patch input size of the tessellation evaluation shader
+as well.
+
+TES_PRIM_MODE
+"""""""""""""
+
+This sets the tessellation primitive mode, one of ``PIPE_PRIM_TRIANGLES``,
+``PIPE_PRIM_QUADS``, or ``PIPE_PRIM_LINES``. (Unlike in GL, there is no
+separate isolines settings, the regular lines is assumed to mean isolines.)
+
+TES_SPACING
+"""""""""""
+
+This sets the spacing mode of the tessellation generator, one of
+``PIPE_TESS_SPACING_*``.
+
+TES_VERTEX_ORDER_CW
+"""""""""""""""""""
+
+This sets the vertex order to be clockwise if the value is 1, or
+counter-clockwise if set to 0.
+
+TES_POINT_MODE
+""""""""""""""
+
+If set to a non-zero value, this turns on point mode for the tessellator,
+which means that points will be generated instead of primitives.
Texture Sampling and Texture Formats
projects / mesa.git / blobdiff