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, 1.84467e+019) : clamp(1 / src.x, -1.84467e+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::
for array textures src0.y contains the slice for 1D,
and src0.z contain the slice for 2D.
- for shadow textures with no arrays, src0.z contains
- the reference value.
+ 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.
+ the reference value for 2D arrays and cube maps.
- There is no way to pass a bias in the .w value for
- shadow arrays, and GLSL doesn't allow this.
- GLSL does allow cube shadows maps to take a bias value,
- and we have to determine how this will look in TGSI.
+ for cube map array shadow textures, the reference value
+ cannot be passed in src0.w, and TEX2 must be used instead.
.. math::
coord = src0
- bias = 0.0
+ shadow_ref = src0.z or src0.w (optional)
+
+ unit = src1
+
+ dst = texture\_sample(unit, coord, shadow_ref)
+
+
+.. opcode:: TEX2 - Texture Lookup (for shadow cube map arrays only)
+
+ this is the same as TEX, but uses another reg to encode the
+ reference value.
+
+.. math::
+
+ coord = src0
+
+ shadow_ref = src1.x
+
+ unit = src2
+
+ dst = texture\_sample(unit, coord, shadow_ref)
+
+
- dst = texture\_sample(unit, coord, bias)
.. opcode:: TXD - Texture Lookup with Derivatives
ddy = src2
- bias = 0.0
+ unit = src3
- dst = texture\_sample\_deriv(unit, coord, bias, ddx, ddy)
+ dst = texture\_sample\_deriv(unit, coord, ddx, ddy)
.. opcode:: TXP - Projective Texture Lookup
.. math::
- coord.x = src0.x / src.w
+ coord.x = src0.x / src0.w
- coord.y = src0.y / src.w
+ coord.y = src0.y / src0.w
- coord.z = src0.z / src.w
+ coord.z = src0.z / src0.w
coord.w = src0.w
- bias = 0.0
+ unit = src1
- dst = texture\_sample(unit, coord, bias)
+ dst = texture\_sample(unit, coord)
.. opcode:: UP2H - Unpack Two 16-Bit Floats
Considered for removal.
-.. opcode:: X2D - 2D Coordinate Transformation
-
-.. math::
-
- dst.x = src0.x + src1.x \times src2.x + src1.y \times src2.y
-
- dst.y = src0.y + src1.x \times src2.z + src1.y \times src2.w
-
- dst.z = src0.x + src1.x \times src2.x + src1.y \times src2.y
-
- dst.w = src0.y + src1.x \times src2.z + src1.y \times src2.w
-
-.. note::
-
- Considered for removal.
-
-
-.. opcode:: ARA - Address Register Add
-
- TBD
-
-.. note::
-
- Considered for removal.
.. opcode:: ARR - Address Register Load With Round
.. opcode:: TXB - Texture Lookup With Bias
+ 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 = src.x
+ coord.x = src0.x
- coord.y = src.y
+ coord.y = src0.y
- coord.z = src.z
+ coord.z = src0.z
- coord.w = 1.0
+ coord.w = none
- bias = src.z
+ 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
.. opcode:: TXL - Texture Lookup With explicit LOD
+ 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).
+
.. math::
coord.x = src0.x
coord.z = src0.z
- coord.w = 1.0
+ coord.w = none
lod = src0.w
+ unit = src1
+
+ dst = texture\_sample(unit, coord, lod)
+
+
+.. opcode:: TXL2 - Texture Lookup With explicit LOD (for cube map arrays only)
+
+ 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)
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. src 1 is a 3 component constant signed
- integer vector, with each component only have a range of -8..+8 (hw only
- seems to deal with this range, interface allows for up to unsigned int).
+ 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).
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)
+ 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.
+
.. math::
dst.z = texture\_depth(unit, lod)
+ dst.w = texture\_levels(unit)
+
.. opcode:: TG4 - Texture Gather
As per ARB_texture_gather, gathers the four texels to be used in a bi-linear
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
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. opcode:: EMIT - Emit
- Generate a new vertex for the current primitive using the values in the
- output registers.
+ 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 (consisting of the emitted vertices),
- and start a new one.
+ Complete the current primitive in the specified vertex stream (consisting of
+ the emitted vertices), and start a new one.
GLSL ISA
Ends a switch expression.
-.. opcode:: NRM4 - 4-component Vector Normalise
+Interpolation ISA
+^^^^^^^^^^^^^^^^^
-This instruction replicates its result.
+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``.
-.. math::
+.. opcode:: INTERP_CENTROID - Interpolate at the centroid
+
+ Interpolates the varying specified by src0 at the centroid
+
+.. opcode:: INTERP_SAMPLE - Interpolate at the specified sample
- dst = \frac{src.x}{src.x \times src.x + src.y \times src.y + src.z \times src.z + src.w \times src.w}
+ 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:
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). Only the X value is
+used.
Declaration Interpolate
^^^^^^^^^^^^^^^^^^^^^^^
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
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.
Texture Sampling and Texture Formats
------------------------------------
projects / mesa.git / blobdiff