dst.w = src0.w \times src1.w + src2.w
-.. opcode:: SUB - Subtract
-
-.. 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:: LRP - Linear Interpolate
.. math::
dst.w = src.w - \lfloor src.w\rfloor
-.. opcode:: CLAMP - Clamp
-
-.. math::
-
- dst.x = clamp(src0.x, src1.x, src2.x)
-
- dst.y = clamp(src0.y, src1.y, src2.y)
-
- dst.z = clamp(src0.z, src1.z, src2.z)
-
- dst.w = clamp(src0.w, src1.w, src2.w)
-
-
.. opcode:: FLR - Floor
.. math::
dst.w = 1
-.. opcode:: ABS - Absolute
-
-.. math::
-
- dst.x = |src.x|
-
- dst.y = |src.y|
-
- dst.z = |src.z|
-
- dst.w = |src.w|
-
-
.. opcode:: DPH - Homogeneous Dot Product
This instruction replicates its result.
.. opcode:: PK2H - Pack Two 16-bit Floats
- TBD
+This instruction replicates its result.
+
+.. math::
+
+ dst = f32\_to\_f16(src.x) | f32\_to\_f16(src.y) << 16
.. opcode:: PK2US - Pack Two Unsigned 16-bit Scalars
.. opcode:: UP2H - Unpack Two 16-Bit Floats
- TBD
+.. math::
+
+ dst.x = f16\_to\_f32(src0.x \& 0xffff)
+
+ dst.y = f16\_to\_f32(src0.x >> 16)
+
+ dst.z = f16\_to\_f32(src0.x \& 0xffff)
+
+ dst.w = f16\_to\_f32(src0.x >> 16)
.. note::
For components which don't return a resource dimension, their value
is undefined.
-
.. math::
lod = src0.x
dst.w = texture\_levels(unit)
+
+.. opcode:: TXQS - Texture Samples Query
+
+ This retrieves the number of samples in the texture, and stores it
+ into the x component. The other components are undefined.
+
+.. math::
+
+ dst.x = texture\_samples(unit)
+
+
.. opcode:: TG4 - Texture Gather
As per ARB_texture_gather, gathers the four texels to be used in a bi-linear
.. 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.
+ Like GLSL bitfieldExtract. 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 offset < 0 or bits < 0 or offset + bits > 32:
+ return undefined
if bits == 0: return 0
# Note: >> sign-extends
- if width + offset < 32:
- return (value << (32 - offset - bits)) >> (32 - bits)
- else:
- return value >> offset
+ return (value << (32 - offset - bits)) >> (32 - bits)
.. opcode:: UBFE - Unsigned Bitfield Extract
- See SM5 instruction of the same name. Extracts a set of bits from the input,
- without any sign-extension.
+ Like GLSL bitfieldExtract. 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 offset < 0 or bits < 0 or offset + bits > 32:
+ return undefined
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
+ return (value << (32 - offset - bits)) >> (32 - bits)
.. opcode:: BFI - Bitfield Insert
- See SM5 instruction of the same name. Replaces a bit region of 'base' with
- the low bits of 'insert'.
+ Like GLSL bitfieldInsert. 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
+ if offset < 0 or bits < 0 or offset + bits > 32:
+ return undefined
+ # << defined such that mask == ~0 when bits == 32, offset == 0
mask = ((1 << bits) - 1) << offset
return ((insert << offset) & mask) | (base & ~mask)
.. opcode:: DABS - Absolute
+.. math::
+
dst.xy = |src0.xy|
+
dst.zw = |src0.zw|
.. opcode:: DADD - Add
dst.zw = src0.zw \times src1.zw + src2.zw
+.. opcode:: DDIV - Divide
+
+.. math::
+
+ dst.xy = \frac{src0.xy}{src1.xy}
+
+ dst.zw = \frac{src0.zw}{src1.zw}
+
+
.. opcode:: DRCP - Reciprocal
.. math::
dst.y = unsigned(src0.zw)
+64-bit Integer ISA
+^^^^^^^^^^^^^^^^^^
+
+The 64-bit integer opcodes reinterpret four-component vectors into
+two-component vectors with 64-bits in each component.
+
+.. opcode:: I64ABS - 64-bit Integer Absolute Value
+
+.. math::
+
+ dst.xy = |src0.xy|
+
+ dst.zw = |src0.zw|
+
+.. opcode:: I64NEG - 64-bit Integer Negate
+
+ Two's complement.
+
+.. math::
+
+ dst.xy = -src.xy
+
+ dst.zw = -src.zw
+
+.. opcode:: I64SSG - 64-bit Integer Set Sign
+
+.. math::
+
+ dst.xy = (src0.xy < 0) ? -1 : (src0.xy > 0) ? 1 : 0
+
+ dst.zw = (src0.zw < 0) ? -1 : (src0.zw > 0) ? 1 : 0
+
+.. opcode:: U64ADD - 64-bit Integer Add
+
+.. math::
+
+ dst.xy = src0.xy + src1.xy
+
+ dst.zw = src0.zw + src1.zw
+
+.. opcode:: U64MUL - 64-bit Integer Multiply
+
+.. math::
+
+ dst.xy = src0.xy * src1.xy
+
+ dst.zw = src0.zw * src1.zw
+
+.. opcode:: U64SEQ - 64-bit Integer Set on Equal
+
+.. math::
+
+ dst.x = src0.xy == src1.xy ? \sim 0 : 0
+
+ dst.z = src0.zw == src1.zw ? \sim 0 : 0
+
+.. opcode:: U64SNE - 64-bit Integer Set on Not Equal
+
+.. math::
+
+ dst.x = src0.xy != src1.xy ? \sim 0 : 0
+
+ dst.z = src0.zw != src1.zw ? \sim 0 : 0
+
+.. opcode:: U64SLT - 64-bit Unsigned Integer Set on Less Than
+
+.. math::
+
+ dst.x = src0.xy < src1.xy ? \sim 0 : 0
+
+ dst.z = src0.zw < src1.zw ? \sim 0 : 0
+
+.. opcode:: U64SGE - 64-bit Unsigned Integer Set on Greater Equal
+
+.. math::
+
+ dst.x = src0.xy >= src1.xy ? \sim 0 : 0
+
+ dst.z = src0.zw >= src1.zw ? \sim 0 : 0
+
+.. opcode:: I64SLT - 64-bit Signed Integer Set on Less Than
+
+.. math::
+
+ dst.x = src0.xy < src1.xy ? \sim 0 : 0
+
+ dst.z = src0.zw < src1.zw ? \sim 0 : 0
+
+.. opcode:: I64SGE - 64-bit Signed Integer Set on Greater Equal
+
+.. math::
+
+ dst.x = src0.xy >= src1.xy ? \sim 0 : 0
+
+ dst.z = src0.zw >= src1.zw ? \sim 0 : 0
+
+.. opcode:: I64MIN - Minimum of 64-bit Signed Integers
+
+.. math::
+
+ dst.xy = min(src0.xy, src1.xy)
+
+ dst.zw = min(src0.zw, src1.zw)
+
+.. opcode:: U64MIN - Minimum of 64-bit Unsigned Integers
+
+.. math::
+
+ dst.xy = min(src0.xy, src1.xy)
+
+ dst.zw = min(src0.zw, src1.zw)
+
+.. opcode:: I64MAX - Maximum of 64-bit Signed Integers
+
+.. math::
+
+ dst.xy = max(src0.xy, src1.xy)
+
+ dst.zw = max(src0.zw, src1.zw)
+
+.. opcode:: U64MAX - Maximum of 64-bit Unsigned Integers
+
+.. math::
+
+ dst.xy = max(src0.xy, src1.xy)
+
+ dst.zw = max(src0.zw, src1.zw)
+
+.. opcode:: U64SHL - Shift Left 64-bit Unsigned Integer
+
+ The shift count is masked with 0x3f before the shift is applied.
+
+.. math::
+
+ dst.xy = src0.xy << (0x3f \& src1.x)
+
+ dst.zw = src0.zw << (0x3f \& src1.y)
+
+.. opcode:: I64SHR - Arithmetic Shift Right (of 64-bit Signed Integer)
+
+ The shift count is masked with 0x3f before the shift is applied.
+
+.. math::
+
+ dst.xy = src0.xy >> (0x3f \& src1.x)
+
+ dst.zw = src0.zw >> (0x3f \& src1.y)
+
+.. opcode:: U64SHR - Logical Shift Right (of 64-bit Unsigned Integer)
+
+ The shift count is masked with 0x3f before the shift is applied.
+
+.. math::
+
+ dst.xy = src0.xy >> (unsigned) (0x3f \& src1.x)
+
+ dst.zw = src0.zw >> (unsigned) (0x3f \& src1.y)
+
+.. opcode:: I64DIV - 64-bit Signed Integer Division
+
+.. math::
+
+ dst.xy = src0.xy \ src1.xy
+
+ dst.zw = src0.zw \ src1.zw
+
+.. opcode:: U64DIV - 64-bit Unsigned Integer Division
+
+.. math::
+
+ dst.xy = src0.xy \ src1.xy
+
+ dst.zw = src0.zw \ src1.zw
+
+.. opcode:: U64MOD - 64-bit Unsigned Integer Remainder
+
+.. math::
+
+ dst.xy = src0.xy \bmod src1.xy
+
+ dst.zw = src0.zw \bmod src1.zw
+
+.. opcode:: I64MOD - 64-bit Signed Integer Remainder
+
+.. math::
+
+ dst.xy = src0.xy \bmod src1.xy
+
+ dst.zw = src0.zw \bmod src1.zw
+
+.. opcode:: F2U64 - Float to 64-bit Unsigned Int
+
+.. math::
+
+ dst.xy = (uint64_t) src0.x
+
+ dst.zw = (uint64_t) src0.y
+
+.. opcode:: F2I64 - Float to 64-bit Int
+
+.. math::
+
+ dst.xy = (int64_t) src0.x
+
+ dst.zw = (int64_t) src0.y
+
+.. opcode:: U2I64 - Unsigned Integer to 64-bit Integer
+
+ This is a zero extension.
+
+.. math::
+
+ dst.xy = (uint64_t) src0.x
+
+ dst.zw = (uint64_t) src0.y
+
+.. opcode:: I2I64 - Signed Integer to 64-bit Integer
+
+ This is a sign extension.
+
+.. math::
+
+ dst.xy = (int64_t) src0.x
+
+ dst.zw = (int64_t) src0.y
+
+.. opcode:: D2U64 - Double to 64-bit Unsigned Int
+
+.. math::
+
+ dst.xy = (uint64_t) src0.xy
+
+ dst.zw = (uint64_t) src0.zw
+
+.. opcode:: D2I64 - Double to 64-bit Int
+
+.. math::
+
+ dst.xy = (int64_t) src0.xy
+
+ dst.zw = (int64_t) src0.zw
+
+.. opcode:: U642F - 64-bit unsigned integer to float
+
+.. math::
+
+ dst.x = (float) src0.xy
+
+ dst.y = (float) src0.zw
+
+.. opcode:: I642F - 64-bit Int to Float
+
+.. math::
+
+ dst.x = (float) src0.xy
+
+ dst.y = (float) src0.zw
+
+.. opcode:: U642D - 64-bit unsigned integer to double
+
+.. math::
+
+ dst.xy = (double) src0.xy
+
+ dst.zw = (double) src0.zw
+
+.. opcode:: I642D - 64-bit Int to double
+
+.. math::
+
+ dst.xy = (double) src0.xy
+
+ dst.zw = (double) src0.zw
+
.. _samplingopcodes:
Resource Sampling Opcodes
.. 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
+ filtering mode identified by the given sampler. The source data may come from
any resource type other than buffers.
Syntax: ``SAMPLE dst, address, sampler_view, sampler``
Resource Access Opcodes
^^^^^^^^^^^^^^^^^^^^^^^
-.. opcode:: LOAD - Fetch data from a shader resource
+.. opcode:: LOAD - Fetch data from a shader buffer or image
Syntax: ``LOAD dst, resource, address``
- Example: ``LOAD TEMP[0], RES[0], TEMP[1]``
+ Example: ``LOAD TEMP[0], BUFFER[0], TEMP[1]``
Using the provided integer address, LOAD fetches data
from the specified buffer or texture without any
texture arrays and 2D textures. address.w is always
ignored.
+ A swizzle suffix may be added to the resource argument
+ this will cause the resource data to be swizzled accordingly.
+
.. opcode:: STORE - Write data to a shader resource
Syntax: ``STORE resource, address, src``
- Example: ``STORE RES[0], TEMP[0], TEMP[1]``
+ Example: ``STORE BUFFER[0], TEMP[0], TEMP[1]``
Using the provided integer address, STORE writes data
to the specified buffer or texture.
texture arrays and 2D textures. address.w is always
ignored.
+.. opcode:: RESQ - Query information about a resource
+
+ Syntax: ``RESQ dst, resource``
+
+ Example: ``RESQ TEMP[0], BUFFER[0]``
+
+ Returns information about the buffer or image resource. For buffer
+ resources, the size (in bytes) is returned in the x component. For
+ image resources, .xyz will contain the width/height/layers of the
+ image, while .w will contain the number of samples for multi-sampled
+ images.
+
+.. opcode:: FBFETCH - Load data from framebuffer
+
+ Syntax: ``FBFETCH dst, output``
+
+ Example: ``FBFETCH TEMP[0], OUT[0]``
+
+ This is only valid on ``COLOR`` semantic outputs. Returns the color
+ of the current position in the framebuffer from before this fragment
+ shader invocation. May return the same value from multiple calls for
+ a particular output within a single invocation. Note that result may
+ be undefined if a fragment is drawn multiple times without a blend
+ barrier in between.
+
.. _threadsyncopcodes:
the program. Results are unspecified if any of the remaining
threads terminates or never reaches an executed BARRIER instruction.
+.. opcode:: MEMBAR - Memory barrier
+
+ ``MEMBAR type``
+
+ This opcode waits for the completion of all memory accesses based on
+ the type passed in. The type is an immediate bitfield with the following
+ meaning:
+
+ Bit 0: Shader storage buffers
+ Bit 1: Atomic buffers
+ Bit 2: Images
+ Bit 3: Shared memory
+ Bit 4: Thread group
+
+ These may be passed in in any combination. An implementation is free to not
+ distinguish between these as it sees fit. However these map to all the
+ possibilities made available by GLSL.
.. _atomopcodes:
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.
+entire execution of the atomic operation. The resource may be a buffer
+or an image. In the case of an image, the offset works the same as for
+``LOAD`` and ``STORE``, specified above. These atomic operations may
+only be used with 32-bit integer image formats.
.. opcode:: ATOMUADD - Atomic integer addition
Syntax: ``ATOMUADD dst, resource, offset, src``
- Example: ``ATOMUADD TEMP[0], RES[0], TEMP[1], TEMP[2]``
+ Example: ``ATOMUADD TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
- The following operation is performed atomically on each component:
+ The following operation is performed atomically:
.. math::
- dst_i = resource[offset]_i
+ dst_x = resource[offset]
- resource[offset]_i = dst_i + src_i
+ resource[offset] = dst_x + src_x
.. opcode:: ATOMXCHG - Atomic exchange
Syntax: ``ATOMXCHG dst, resource, offset, src``
- Example: ``ATOMXCHG TEMP[0], RES[0], TEMP[1], TEMP[2]``
+ Example: ``ATOMXCHG TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
- The following operation is performed atomically on each component:
+ The following operation is performed atomically:
.. math::
- dst_i = resource[offset]_i
+ dst_x = resource[offset]
- resource[offset]_i = src_i
+ resource[offset] = src_x
.. opcode:: ATOMCAS - Atomic compare-and-exchange
Syntax: ``ATOMCAS dst, resource, offset, cmp, src``
- Example: ``ATOMCAS TEMP[0], RES[0], TEMP[1], TEMP[2], TEMP[3]``
+ Example: ``ATOMCAS TEMP[0], BUFFER[0], TEMP[1], TEMP[2], TEMP[3]``
- The following operation is performed atomically on each component:
+ The following operation is performed atomically:
.. math::
- dst_i = resource[offset]_i
+ dst_x = resource[offset]
- resource[offset]_i = (dst_i == cmp_i ? src_i : dst_i)
+ resource[offset] = (dst_x == cmp_x ? src_x : dst_x)
.. opcode:: ATOMAND - Atomic bitwise And
Syntax: ``ATOMAND dst, resource, offset, src``
- Example: ``ATOMAND TEMP[0], RES[0], TEMP[1], TEMP[2]``
+ Example: ``ATOMAND TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
- The following operation is performed atomically on each component:
+ The following operation is performed atomically:
.. math::
- dst_i = resource[offset]_i
+ dst_x = resource[offset]
- resource[offset]_i = dst_i \& src_i
+ resource[offset] = dst_x \& src_x
.. opcode:: ATOMOR - Atomic bitwise Or
Syntax: ``ATOMOR dst, resource, offset, src``
- Example: ``ATOMOR TEMP[0], RES[0], TEMP[1], TEMP[2]``
+ Example: ``ATOMOR TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
- The following operation is performed atomically on each component:
+ The following operation is performed atomically:
.. math::
- dst_i = resource[offset]_i
+ dst_x = resource[offset]
- resource[offset]_i = dst_i | src_i
+ resource[offset] = dst_x | src_x
.. opcode:: ATOMXOR - Atomic bitwise Xor
Syntax: ``ATOMXOR dst, resource, offset, src``
- Example: ``ATOMXOR TEMP[0], RES[0], TEMP[1], TEMP[2]``
+ Example: ``ATOMXOR TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
- The following operation is performed atomically on each component:
+ The following operation is performed atomically:
.. math::
- dst_i = resource[offset]_i
+ dst_x = resource[offset]
- resource[offset]_i = dst_i \oplus src_i
+ resource[offset] = dst_x \oplus src_x
.. opcode:: ATOMUMIN - Atomic unsigned minimum
Syntax: ``ATOMUMIN dst, resource, offset, src``
- Example: ``ATOMUMIN TEMP[0], RES[0], TEMP[1], TEMP[2]``
+ Example: ``ATOMUMIN TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
- The following operation is performed atomically on each component:
+ The following operation is performed atomically:
.. math::
- dst_i = resource[offset]_i
+ dst_x = resource[offset]
- resource[offset]_i = (dst_i < src_i ? dst_i : src_i)
+ resource[offset] = (dst_x < src_x ? dst_x : src_x)
.. opcode:: ATOMUMAX - Atomic unsigned maximum
Syntax: ``ATOMUMAX dst, resource, offset, src``
- Example: ``ATOMUMAX TEMP[0], RES[0], TEMP[1], TEMP[2]``
+ Example: ``ATOMUMAX TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
- The following operation is performed atomically on each component:
+ The following operation is performed atomically:
.. math::
- dst_i = resource[offset]_i
+ dst_x = resource[offset]
- resource[offset]_i = (dst_i > src_i ? dst_i : src_i)
+ resource[offset] = (dst_x > src_x ? dst_x : src_x)
.. opcode:: ATOMIMIN - Atomic signed minimum
Syntax: ``ATOMIMIN dst, resource, offset, src``
- Example: ``ATOMIMIN TEMP[0], RES[0], TEMP[1], TEMP[2]``
+ Example: ``ATOMIMIN TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
- The following operation is performed atomically on each component:
+ The following operation is performed atomically:
.. math::
- dst_i = resource[offset]_i
+ dst_x = resource[offset]
- resource[offset]_i = (dst_i < src_i ? dst_i : src_i)
+ resource[offset] = (dst_x < src_x ? dst_x : src_x)
.. opcode:: ATOMIMAX - Atomic signed maximum
Syntax: ``ATOMIMAX dst, resource, offset, src``
- Example: ``ATOMIMAX TEMP[0], RES[0], TEMP[1], TEMP[2]``
+ Example: ``ATOMIMAX TEMP[0], BUFFER[0], TEMP[1], TEMP[2]``
- The following operation is performed atomically on each component:
+ The following operation is performed atomically:
.. math::
- dst_i = resource[offset]_i
+ dst_x = resource[offset]
+
+ resource[offset] = (dst_x > src_x ? dst_x : src_x)
+
+
+.. _voteopcodes:
+
+Vote opcodes
+^^^^^^^^^^^^
- resource[offset]_i = (dst_i > src_i ? dst_i : src_i)
+These opcodes compare the given value across the shader invocations
+running in the current SIMD group. The details of exactly which
+invocations get compared are implementation-defined, and it would be a
+correct implementation to only ever consider the current thread's
+value. (i.e. SIMD group of 1). The argument is treated as a boolean.
+.. opcode:: VOTE_ANY - Value is set in any of the current invocations
+
+.. opcode:: VOTE_ALL - Value is set in all of the current invocations
+
+.. opcode:: VOTE_EQ - Value is the same in all of the current invocations
Explanation of symbols used
^^^^^^^^^^^^^^^^^^^^^^^^
Declarations can optional have an ArrayID attribute which can be referred by
-indirect addressing operands. An ArrayID of zero is reserved and treaded as
+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
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 will be divided by the W value to get normalized device coordinates.
For fragment shaders, TGSI_SEMANTIC_POSITION is used to indicate that
-fragment shader input contains the fragment's window position. The X
+fragment shader input (or system value, depending on which one is
+supported by the driver) contains the fragment's window position. The X
component starts at zero and always increases from left to right.
The Y component starts at zero and always increases but Y=0 may either
indicate the top of the window or the bottom depending on the fragment
"""""""""""""""""""
For vertex shader outputs or fragment shader inputs/outputs, this
-label indicates that the resister contains an R,G,B,A color.
+label indicates that the register contains an R,G,B,A color.
Several shader inputs/outputs may contain colors so the semantic index
is used to distinguish them. For example, color[0] may be the diffuse
TGSI_SEMANTIC_FACE
""""""""""""""""""
-This label applies to fragment shader inputs only and indicates that
-the register contains front/back-face information of the form (F, 0,
-0, 1). The first component will be positive when the fragment belongs
-to a front-facing polygon, and negative when the fragment belongs to a
-back-facing polygon.
+This label applies to fragment shader inputs (or system values,
+depending on which one is supported by the driver) and indicates that
+the register contains front/back-face information.
+
+If it is an input, it will be a floating-point vector in the form (F, 0, 0, 1),
+where F will be positive when the fragment belongs to a front-facing polygon,
+and negative when the fragment belongs to a back-facing polygon.
+
+If it is a system value, it will be an integer vector in the form (F, 0, 0, 1),
+where F is 0xffffffff when the fragment belongs to a front-facing polygon and
+0 when the fragment belongs to a back-facing polygon.
TGSI_SEMANTIC_EDGEFLAG
TGSI_SEMANTIC_CLIPDIST
""""""""""""""""""""""
+Note this covers clipping and culling distances.
+
When components of vertex elements are identified this way, these
values are each assumed to be a float32 signed distance to a plane.
+
+For clip distances:
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
+the interpolated plane distances are >= 0.
+
+For cull distances:
+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);
+
+Multiple clip/cull 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.
+The properties NUM_CLIPDIST_ENABLED and NUM_CULLDIST_ENABLED
+are used to divide up the 2 x vec4 space between clipping and culling.
TGSI_SEMANTIC_SAMPLEID
""""""""""""""""""""""
For tessellation evaluation/control shaders, this semantic label indicates the
number of vertices provided in the input patch. Only the X value is defined.
+TGSI_SEMANTIC_HELPER_INVOCATION
+"""""""""""""""""""""""""""""""
+
+For fragment shaders, this semantic indicates whether the current
+invocation is covered or not. Helper invocations are created in order
+to properly compute derivatives, however it may be desirable to skip
+some of the logic in those cases. See ``gl_HelperInvocation`` documentation.
+
+TGSI_SEMANTIC_BASEINSTANCE
+""""""""""""""""""""""""""
+
+For vertex shaders, the base instance argument supplied for this
+draw. This is an integer value, and only the X component is used.
+
+TGSI_SEMANTIC_DRAWID
+""""""""""""""""""""
+
+For vertex shaders, the zero-based index of the current draw in a
+``glMultiDraw*`` invocation. This is an integer value, and only the X
+component is used.
+
+
+TGSI_SEMANTIC_WORK_DIM
+""""""""""""""""""""""
+
+For compute shaders started via opencl this retrieves the work_dim
+parameter to the clEnqueueNDRangeKernel call with which the shader
+was started.
+
+
+TGSI_SEMANTIC_GRID_SIZE
+"""""""""""""""""""""""
+
+For compute shaders, this semantic indicates the maximum (x, y, z) dimensions
+of a grid of thread blocks.
+
+
+TGSI_SEMANTIC_BLOCK_ID
+""""""""""""""""""""""
+
+For compute shaders, this semantic indicates the (x, y, z) coordinates of the
+current block inside of the grid.
+
+
+TGSI_SEMANTIC_BLOCK_SIZE
+""""""""""""""""""""""""
+
+For compute shaders, this semantic indicates the maximum (x, y, z) dimensions
+of a block in threads.
+
+
+TGSI_SEMANTIC_THREAD_ID
+"""""""""""""""""""""""
+
+For compute shaders, this semantic indicates the (x, y, z) coordinates of the
+current thread inside of the block.
+
Declaration Interpolate
^^^^^^^^^^^^^^^^^^^^^^^
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.
+NUM_CLIPDIST_ENABLED
+""""""""""""""""""""
+
+How many clip distance scalar outputs are enabled.
+
+NUM_CULLDIST_ENABLED
+""""""""""""""""""""
+
+How many cull distance scalar outputs are enabled.
+
+FS_EARLY_DEPTH_STENCIL
+""""""""""""""""""""""
+
+Whether depth test, stencil test, and occlusion query should run before
+the fragment shader (regardless of fragment shader side effects). Corresponds
+to GLSL early_fragment_tests.
+
+NEXT_SHADER
+"""""""""""
+
+Which shader stage will MOST LIKELY follow after this shader when the shader
+is bound. This is only a hint to the driver and doesn't have to be precise.
+Only set for VS and TES.
+
+CS_FIXED_BLOCK_WIDTH / HEIGHT / DEPTH
+"""""""""""""""""""""""""""""""""""""
+
+Threads per block in each dimension, if known at compile time. If the block size
+is known all three should be at least 1. If it is unknown they should all be set
+to 0 or not set.
+
+MUL_ZERO_WINS
+"""""""""""""
+
+The MUL TGSI operation (FP32 multiplication) will return 0 if either
+of the operands are equal to 0. That means that 0 * Inf = 0. This
+should be set the same way for an entire pipeline. Note that this
+applies not only to the literal MUL TGSI opcode, but all FP32
+multiplications implied by other operations, such as MAD, FMA, DP2,
+DP3, DP4, DPH, DST, LOG, LRP, XPD, and possibly others. If there is a
+mismatch between shaders, then it is unspecified whether this behavior
+will be enabled.
+
Texture Sampling and Texture Formats
------------------------------------
projects / mesa.git / blobdiff