TGSI ==== TGSI, Tungsten Graphics Shader Instructions, is an intermediate language for describing shaders. Since Gallium is inherently shaderful, shaders are an important part of the API. TGSI is the only intermediate representation used by all drivers. From GL_NV_vertex_program ------------------------- ARL - Address Register Load .. math:: dst.x = \lfloor src.x\rfloor dst.y = \lfloor src.y\rfloor dst.z = \lfloor src.z\rfloor dst.w = \lfloor src.w\rfloor MOV - Move .. math:: dst.x = src.x dst.y = src.y dst.z = src.z dst.w = src.w LIT - Light Coefficients .. math:: dst.x = 1.0 dst.y = max(src.x, 0.0) dst.z = (src.x > 0.0) ? max(src.y, 0.0)^{clamp(src.w, -128.0, 128.0))} : 0.0 dst.w = 1.0 RCP - Reciprocal .. math:: dst.x = \frac{1}{src.x} dst.y = \frac{1}{src.x} dst.z = \frac{1}{src.x} dst.w = \frac{1}{src.x} RSQ - Reciprocal Square Root .. math:: dst.x = \frac{1}{\sqrt{|src.x|}} dst.y = \frac{1}{\sqrt{|src.x|}} dst.z = \frac{1}{\sqrt{|src.x|}} dst.w = \frac{1}{\sqrt{|src.x|}} EXP - Approximate Exponential Base 2 .. math:: dst.x = 2^{\lfloor src.x\rfloor} dst.y = src.x - \lfloor src.x\rfloor dst.z = 2^{src.x} dst.w = 1.0 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 MUL - Multiply .. 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 ADD - Add .. 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 DP3 - 3-component Dot Product .. math:: dst.x = src0.x * src1.x + src0.y * src1.y + src0.z * src1.z dst.y = src0.x * src1.x + src0.y * src1.y + src0.z * src1.z dst.z = src0.x * src1.x + src0.y * src1.y + src0.z * src1.z dst.w = src0.x * src1.x + src0.y * src1.y + src0.z * src1.z DP4 - 4-component Dot Product .. math:: dst.x = src0.x * src1.x + src0.y * src1.y + src0.z * src1.z + src0.w * src1.w dst.y = src0.x * src1.x + src0.y * src1.y + src0.z * src1.z + src0.w * src1.w dst.z = src0.x * src1.x + src0.y * src1.y + src0.z * src1.z + src0.w * src1.w dst.w = src0.x * src1.x + src0.y * src1.y + src0.z * src1.z + src0.w * src1.w DST - Distance Vector .. math:: dst.x = 1.0 dst.y = src0.y * src1.y dst.z = src0.z dst.w = src1.w MIN - Minimum .. 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) MAX - Maximum .. 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) SLT - Set On Less Than .. math:: dst.x = (src0.x < src1.x) ? 1.0 : 0.0 dst.y = (src0.y < src1.y) ? 1.0 : 0.0 dst.z = (src0.z < src1.z) ? 1.0 : 0.0 dst.w = (src0.w < src1.w) ? 1.0 : 0.0 SGE - Set On Greater Equal Than .. math:: dst.x = (src0.x >= src1.x) ? 1.0 : 0.0 dst.y = (src0.y >= src1.y) ? 1.0 : 0.0 dst.z = (src0.z >= src1.z) ? 1.0 : 0.0 dst.w = (src0.w >= src1.w) ? 1.0 : 0.0 MAD - Multiply And Add .. 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 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 LRP - Linear Interpolate .. math:: dst.x = src0.x * (src1.x - src2.x) + src2.x dst.y = src0.y * (src1.y - src2.y) + src2.y dst.z = src0.z * (src1.z - src2.z) + src2.z dst.w = src0.w * (src1.w - src2.w) + src2.w CND - Condition .. math:: dst.x = (src2.x > 0.5) ? src0.x : src1.x dst.y = (src2.y > 0.5) ? src0.y : src1.y dst.z = (src2.z > 0.5) ? src0.z : src1.z dst.w = (src2.w > 0.5) ? src0.w : src1.w DP2A - 2-component Dot Product And Add .. math:: dst.x = src0.x * src1.x + src0.y * src1.y + src2.x dst.y = src0.x * src1.x + src0.y * src1.y + src2.x dst.z = src0.x * src1.x + src0.y * src1.y + src2.x dst.w = src0.x * src1.x + src0.y * src1.y + src2.x FRAC - Fraction .. math:: dst.x = src.x - \lfloor src.x\rfloor dst.y = src.y - \lfloor src.y\rfloor dst.z = src.z - \lfloor src.z\rfloor dst.w = src.w - \lfloor src.w\rfloor 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) FLR - Floor This is identical to ARL. .. math:: dst.x = \lfloor src.x\rfloor dst.y = \lfloor src.y\rfloor dst.z = \lfloor src.z\rfloor dst.w = \lfloor src.w\rfloor 1.3.9 ROUND - Round .. math:: dst.x = round(src.x) dst.y = round(src.y) dst.z = round(src.z) dst.w = round(src.w) EX2 - Exponential Base 2 .. math:: dst.x = 2^{src.x} dst.y = 2^{src.x} dst.z = 2^{src.x} dst.w = 2^{src.x} LG2 - Logarithm Base 2 .. math:: dst.x = \log_2{src.x} dst.y = \log_2{src.x} dst.z = \log_2{src.x} dst.w = \log_2{src.x} POW - Power .. math:: dst.x = src0.x^{src1.x} dst.y = src0.x^{src1.x} dst.z = src0.x^{src1.x} dst.w = src0.x^{src1.x} 1.3.15 XPD - Cross Product .. math:: dst.x = src0.y * src1.z - src1.y * src0.z dst.y = src0.z * src1.x - src1.z * src0.x dst.z = src0.x * src1.y - src1.x * src0.y dst.w = 1.0 ABS - Absolute .. math:: dst.x = |src.x| dst.y = |src.y| dst.z = |src.z| dst.w = |src.w| 1.4.2 RCC - Reciprocal Clamped .. math:: dst.x = (1.0 / src.x) > 0.0 ? clamp(1.0 / src.x, 5.42101e-020, 1.884467e+019) : clamp(1.0 / src.x, -1.884467e+019, -5.42101e-020) dst.y = (1.0 / src.x) > 0.0 ? clamp(1.0 / src.x, 5.42101e-020, 1.884467e+019) : clamp(1.0 / src.x, -1.884467e+019, -5.42101e-020) dst.z = (1.0 / src.x) > 0.0 ? clamp(1.0 / src.x, 5.42101e-020, 1.884467e+019) : clamp(1.0 / src.x, -1.884467e+019, -5.42101e-020) dst.w = (1.0 / src.x) > 0.0 ? clamp(1.0 / src.x, 5.42101e-020, 1.884467e+019) : clamp(1.0 / src.x, -1.884467e+019, -5.42101e-020) 1.4.3 DPH - Homogeneous Dot Product .. math:: dst.x = src0.x * src1.x + src0.y * src1.y + src0.z * src1.z + src1.w dst.y = src0.x * src1.x + src0.y * src1.y + src0.z * src1.z + src1.w dst.z = src0.x * src1.x + src0.y * src1.y + src0.z * src1.z + src1.w dst.w = src0.x * src1.x + src0.y * src1.y + src0.z * src1.z + src1.w COS - Cosine .. math:: dst.x = \cos{src.x} dst.y = \cos{src.x} dst.z = \cos{src.x} dst.w = \cos{src.w} 1.5.2 DDX - Derivative Relative To X .. math:: dst.x = partialx(src.x) dst.y = partialx(src.y) dst.z = partialx(src.z) dst.w = partialx(src.w) 1.5.3 DDY - Derivative Relative To Y .. math:: dst.x = partialy(src.x) dst.y = partialy(src.y) dst.z = partialy(src.z) dst.w = partialy(src.w) 1.5.7 KILP - Predicated Discard .. math:: discard 1.5.10 PK2H - Pack Two 16-bit Floats TBD 1.5.11 PK2US - Pack Two Unsigned 16-bit Scalars TBD 1.5.12 PK4B - Pack Four Signed 8-bit Scalars TBD 1.5.13 PK4UB - Pack Four Unsigned 8-bit Scalars TBD 1.5.15 RFL - Reflection Vector .. math:: dst.x = 2.0 * (src0.x * src1.x + src0.y * src1.y + src0.z * src1.z) / (src0.x * src0.x + src0.y * src0.y + src0.z * src0.z) * src0.x - src1.x dst.y = 2.0 * (src0.x * src1.x + src0.y * src1.y + src0.z * src1.z) / (src0.x * src0.x + src0.y * src0.y + src0.z * src0.z) * src0.y - src1.y dst.z = 2.0 * (src0.x * src1.x + src0.y * src1.y + src0.z * src1.z) / (src0.x * src0.x + src0.y * src0.y + src0.z * src0.z) * src0.z - src1.z dst.w = 1.0 Considered for removal. 1.5.16 SEQ - Set On Equal .. math:: dst.x = (src0.x == src1.x) ? 1.0 : 0.0 dst.y = (src0.y == src1.y) ? 1.0 : 0.0 dst.z = (src0.z == src1.z) ? 1.0 : 0.0 dst.w = (src0.w == src1.w) ? 1.0 : 0.0 1.5.17 SFL - Set On False .. math:: dst.x = 0.0 dst.y = 0.0 dst.z = 0.0 dst.w = 0.0 Considered for removal. 1.5.18 SGT - Set On Greater Than .. math:: dst.x = (src0.x > src1.x) ? 1.0 : 0.0 dst.y = (src0.y > src1.y) ? 1.0 : 0.0 dst.z = (src0.z > src1.z) ? 1.0 : 0.0 dst.w = (src0.w > src1.w) ? 1.0 : 0.0 SIN - Sine .. math:: dst.x = \sin{src.x} dst.y = \sin{src.x} dst.z = \sin{src.x} dst.w = \sin{src.w} 1.5.20 SLE - Set On Less Equal Than .. math:: dst.x = (src0.x <= src1.x) ? 1.0 : 0.0 dst.y = (src0.y <= src1.y) ? 1.0 : 0.0 dst.z = (src0.z <= src1.z) ? 1.0 : 0.0 dst.w = (src0.w <= src1.w) ? 1.0 : 0.0 1.5.21 SNE - Set On Not Equal .. math:: dst.x = (src0.x != src1.x) ? 1.0 : 0.0 dst.y = (src0.y != src1.y) ? 1.0 : 0.0 dst.z = (src0.z != src1.z) ? 1.0 : 0.0 dst.w = (src0.w != src1.w) ? 1.0 : 0.0 1.5.22 STR - Set On True .. math:: dst.x = 1.0 dst.y = 1.0 dst.z = 1.0 dst.w = 1.0 1.5.23 TEX - Texture Lookup TBD 1.5.24 TXD - Texture Lookup with Derivatives TBD 1.5.25 TXP - Projective Texture Lookup TBD 1.5.26 UP2H - Unpack Two 16-Bit Floats TBD Considered for removal. 1.5.27 UP2US - Unpack Two Unsigned 16-Bit Scalars TBD Considered for removal. 1.5.28 UP4B - Unpack Four Signed 8-Bit Values TBD Considered for removal. 1.5.29 UP4UB - Unpack Four Unsigned 8-Bit Scalars TBD Considered for removal. 1.5.30 X2D - 2D Coordinate Transformation .. math:: dst.x = src0.x + src1.x * src2.x + src1.y * src2.y dst.y = src0.y + src1.x * src2.z + src1.y * src2.w dst.z = src0.x + src1.x * src2.x + src1.y * src2.y dst.w = src0.y + src1.x * src2.z + src1.y * src2.w Considered for removal. 1.6 GL_NV_vertex_program2 -------------------------- 1.6.1 ARA - Address Register Add TBD Considered for removal. 1.6.2 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) 1.6.3 BRA - Branch pc = target Considered for removal. 1.6.4 CAL - Subroutine Call push(pc) pc = target 1.6.5 RET - Subroutine Call Return pc = pop() Potential restrictions: * Only occurs at end of function. 1.6.6 SSG - Set Sign .. math:: dst.x = (src.x > 0.0) ? 1.0 : (src.x < 0.0) ? -1.0 : 0.0 dst.y = (src.y > 0.0) ? 1.0 : (src.y < 0.0) ? -1.0 : 0.0 dst.z = (src.z > 0.0) ? 1.0 : (src.z < 0.0) ? -1.0 : 0.0 dst.w = (src.w > 0.0) ? 1.0 : (src.w < 0.0) ? -1.0 : 0.0 1.8.1 CMP - Compare .. math:: dst.x = (src0.x < 0.0) ? src1.x : src2.x dst.y = (src0.y < 0.0) ? src1.y : src2.y dst.z = (src0.z < 0.0) ? src1.z : src2.z dst.w = (src0.w < 0.0) ? src1.w : src2.w 1.8.2 KIL - Conditional Discard .. math:: if (src.x < 0.0 || src.y < 0.0 || src.z < 0.0 || src.w < 0.0) discard endif SCS - Sine Cosine .. math:: dst.x = \cos{src.x} dst.y = \sin{src.x} dst.z = 0.0 dst.y = 1.0 1.8.4 TXB - Texture Lookup With Bias TBD 1.9.1 NRM - 3-component Vector Normalise .. math:: dst.x = src.x / (src.x * src.x + src.y * src.y + src.z * src.z) dst.y = src.y / (src.x * src.x + src.y * src.y + src.z * src.z) dst.z = src.z / (src.x * src.x + src.y * src.y + src.z * src.z) dst.w = 1.0 1.9.2 DIV - Divide .. 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 1.9.3 DP2 - 2-component Dot Product .. math:: dst.x = src0.x * src1.x + src0.y * src1.y dst.y = src0.x * src1.x + src0.y * src1.y dst.z = src0.x * src1.x + src0.y * src1.y dst.w = src0.x * src1.x + src0.y * src1.y 1.9.5 TXL - Texture Lookup With LOD TBD 1.9.6 BRK - Break TBD 1.9.7 IF - If TBD 1.9.8 BGNFOR - Begin a For-Loop dst.x = floor(src.x) dst.y = floor(src.y) dst.z = floor(src.z) if (dst.y <= 0) pc = [matching ENDFOR] + 1 endif Note: The destination must be a loop register. The source must be a constant register. Considered for cleanup / removal. 1.9.9 REP - Repeat TBD 1.9.10 ELSE - Else TBD 1.9.11 ENDIF - End If TBD 1.9.12 ENDFOR - End a For-Loop dst.x = dst.x + dst.z dst.y = dst.y - 1.0 if (dst.y > 0) pc = [matching BGNFOR instruction] + 1 endif Note: The destination must be a loop register. Considered for cleanup / removal. 1.9.13 ENDREP - End Repeat TBD 1.10.1 PUSHA - Push Address Register On Stack push(src.x) push(src.y) push(src.z) push(src.w) Considered for cleanup / removal. 1.10.2 POPA - Pop Address Register From Stack dst.w = pop() dst.z = pop() dst.y = pop() dst.x = pop() Considered for cleanup / removal. 1.11 GL_NV_gpu_program4 ------------------------ Support for these opcodes indicated by a special pipe capability bit (TBD). CEIL - Ceiling .. math:: dst.x = \lceil src.x\rceil dst.y = \lceil src.y\rceil dst.z = \lceil src.z\rceil dst.w = \lceil src.w\rceil 1.11.2 I2F - Integer To Float .. math:: dst.x = (float) src.x dst.y = (float) src.y dst.z = (float) src.z dst.w = (float) src.w 1.11.3 NOT - Bitwise Not .. math:: dst.x = ~src.x dst.y = ~src.y dst.z = ~src.z dst.w = ~src.w 1.11.4 TRUNC - Truncate .. math:: dst.x = trunc(src.x) dst.y = trunc(src.y) dst.z = trunc(src.z) dst.w = trunc(src.w) 1.11.5 SHL - Shift Left .. math:: dst.x = src0.x << src1.x dst.y = src0.y << src1.x dst.z = src0.z << src1.x dst.w = src0.w << src1.x 1.11.6 SHR - Shift Right .. math:: dst.x = src0.x >> src1.x dst.y = src0.y >> src1.x dst.z = src0.z >> src1.x dst.w = src0.w >> src1.x 1.11.7 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 1.11.8 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 1.11.9 MOD - Modulus .. 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 1.11.10 XOR - Bitwise Xor .. 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 SAD - Sum Of Absolute Differences .. 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 1.11.12 TXF - Texel Fetch TBD 1.11.13 TXQ - Texture Size Query TBD 1.11.14 CONT - Continue TBD 1.12 GL_NV_geometry_program4 ----------------------------- 1.12.1 EMIT - Emit TBD 1.12.2 ENDPRIM - End Primitive TBD 1.13 GLSL ---------- 1.13.1 BGNLOOP - Begin a Loop TBD 1.13.2 BGNSUB - Begin Subroutine TBD 1.13.3 ENDLOOP - End a Loop TBD 1.13.4 ENDSUB - End Subroutine TBD 1.13.10 NOP - No Operation Do nothing. 1.16.7 NRM4 - 4-component Vector Normalise .. math:: dst.x = src.x / (src.x * src.x + src.y * src.y + src.z * src.z + src.w * src.w) dst.y = src.y / (src.x * src.x + src.y * src.y + src.z * src.z + src.w * src.w) dst.z = src.z / (src.x * src.x + src.y * src.y + src.z * src.z + src.w * src.w) dst.w = src.w / (src.x * src.x + src.y * src.y + src.z * src.z + src.w * src.w) 1.17 ps_2_x ------------ 1.17.2 CALLNZ - Subroutine Call If Not Zero TBD 1.17.3 IFC - If TBD 1.17.5 BREAKC - Break Conditional TBD 2 Explanation of symbols used ============================== 2.1 Functions -------------- :math:`|x|` Absolute value of `x`. :math:`\lceil x \rceil` Ceiling of `x`. clamp(x,y,z) Clamp x between y and z. (x < y) ? y : (x > z) ? z : x :math:`\lfloor x\rfloor` Floor of `x`. :math:`\log_2{x}` Logarithm of `x`, base 2. max(x,y) Maximum of x and y. (x > y) ? x : y min(x,y) Minimum of x and y. (x < y) ? x : y partialx(x) Derivative of x relative to fragment's X. partialy(x) Derivative of x relative to fragment's Y. pop() Pop from stack. :math:`x^y` `x` to the power `y`. push(x) Push x on stack. round(x) Round x. trunc(x) Truncate x. 2.2 Keywords ------------- discard Discard fragment. dst First destination register. dst0 First destination register. pc Program counter. src First source register. src0 First source register. src1 Second source register. src2 Third source register. target Label of target instruction. 3 Other tokens =============== 3.1 Declaration Semantic ------------------------- 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. 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. The meanings of the individual semantic names are explained in the following sections. 3.1.1 FACE Valid only in a fragment shader INPUT declaration. FACE.x is negative when the primitive is back facing. FACE.x is positive when the primitive is front facing.