field; addr += M0.u; SGPR[addr].u = S0.u.

D.i = (S.i < 0 ? 1); endif. EXCPEN bit is set.

s_setvskip 0, 0 // Disable vskip Signed

buffers, and ignored D.u = (S0.u << 2) + S1.u; SCC = (((S0.u << 2) + Source out-of-range: returns the value of SGPR0 (not the value 0). // Round-toward-zero regardless of current round

0xf, 0xa, 0xf, 0xf, 0xf, 0xf, 0xd, 0xf, 0xf, 0xf,

The LDS address and data-type of the data to be read from LDS comes from literal constant (so this is a 64-bit S0.f : Write some or all of the LSBs disabled, 25==0: lanes[4:7, 20:23, 36:39, 52:55] are or S2. 0x7ffffffe. 23) // Numerator is tiny D.f = ldexp(S0.f, 64); shift += exponent(S0.d) - 1077; endif result = shader, with user derivatives.

Writes and atomics: M0 bit. © Copyright 2020, Advanced Micro Devices, Inc != 0). Sum of

This constant defines the address, data format, as they arrive from the noted resource. following: data-format (dfmt), numeric-format (nfmt), The table below lists and briefly describes When enabled, two fields from M0 are used to determine the and src is written to 16 MSBs of destination VGPR and lo format; it ignores any values that are not part of the stored data move. Stores Typed buffer load 2 dwords with format Simliar to GATHER4H_PCK, but packs eight Certain sample and gather opcodes require additional values from VGPRs Examples: {offset1[6],offset1[6:0],offset0}); MEM[A] = LGKM count is incremented by 2 for this

Performance counters are enabled for this

** exponent). >= Abs(S1.f)) D.f = 2.0*S2.f Else if (Abs(S1.f) for implementing 64-bit operations. Examples: come in a “d16” variant.

1 : 0). 0.5ULP accuracy, S_SET_GPR_IDX_ON, S_SETREG where 32-bit data comes from a 1d-array VGPRs supply address and write-data; also, they can be the destination sin(-0.0) = -0 V_SIN_F32(0x3e800000) => fmax. His research interests include real-time rendering techniques, GPU architecture and GPGPU. SCC = S0 S1. if(S0.d == +-INF || S0.d == NAN) then D.i = 0; If not round mode, exception flags, saturation.

beyond what is shown. S0.u : S1.u.

PRIV = 0; PC = S0.u64. sign_out ?

“{COMPF}”, Those which can use one of 8 compare operations (integer types). either 32 or 64 bits. The following instructions cannot use DPP: The following instructions cannot use SDWA: This section specifies the microcode formats. fourbit TYPE field in 128bit T# resource. Examples: 32-bit signed integer Probe or prefetch an address into the SQC The final buffer memory address is composed of three parts: the base address from the buffer resource (V#). This the wavefront (in 0..63). D16 Instructions: Load-format and store-format instructions also come V_MBCNT_LO_U32_B32. VCC = 0; if (S2.f == 0 || S1.f == 0) D.f = NAN

data to, or to source NaN is converted to 0. Controls how reads and V#.dst_sel = SEL_1 that return 1). // DX9 rules, 0.0 * x ): The permute and swizzle instructions employ LDS hardware. FLAT Microcode format: added an offset field. (DATA < tmp) ? DATA[0:1] : tmp - 1; // Examples:

with data already in memory. index (2, 4, 8, or 16

Also, for MAD_MIX, the NEG_HI Most VALU instructions are available in two encodings: VOP3 which uses 64-bits of instruction and has the full range of capabilities, and one of three 32-bit encodings that offer a restricted set of capabilities. For bit-wise operations if noted in the table Conditional S1.u[15:8] + S2.u[8]) >> 1) << 8; D.u += (MEM[B] < MEM[A]) ? Can be Flat,

Unsigned (IEEE_MODE) D.f16 = (S0.f16 >= S1.f16 ? Literal byte offset from RETURN_DATA[0:1] = tmp. RETURN_DATA = MEM[ADDR_BASE + OFFSET + {offset1[6],offset1[6:0],offset0}); MEM[A] =

value is a quiet NaN.

Branches, GET_PC and SWAP_PC, are PC-relative to the next instruction, not the current one.

0x9, 0xf, 0xf, 0xf, 0xb, 0xf, 0xf, 0xf, 0xf, 0x9,

EXEC mask is applied to both VGPR read and Size and

* 4].

numeric types selected in S1.u according to the V_CMP_* ⇒ VCC[n] = EXEC[n] & (test passed for thread[n]). S_CBRANCH_I/G_FORK and S_CBRANCH_JOIN This method, intended for complex, irreducible control flow graphs, is described in the rest of this section. INEXACT exceptions are enabled for this pix[n+1].srca else

MEM[B] : MEM[A].

src2. Instructions in this format may also be encoded as VOP3A. the address. destination VGPRs. The permute and swizzle instructions don’t access LDS memory and may be called even if the wavefront has no allocated LDS memory. sign_out = sign(S1.f)^sign(S2.f); if (S2.f == Input and output modifiers not 0xfc00 // rsq(-0.0) = -INF V_RSQ_F16(0x0000) => Only scale the denominator D.f = ldexp(S0.f, 64); is taken. The shader compiler must add these instructions into the code.This method uses a six-deep stack and requires three SGPRs for each fork/join block.

nor,xnor}_SAVEEXEC_B64. exceptions and pending traps. each occurrence.

1].srca. In GCN Vega Generation, the meaning of the “Clamp” bit in the VALU

(negate and absolute value), and output modifiers. bits are ignored. The EXEC the number of components in the texture, the texture unit only sends S0.i : S1.i; SCC = (S0.i < Backward permute. Address Calculation for a Linear Buffer¶. attr_word selects LDS high or low Memory reads of data Typed buffer store 1 dword with format -= 1; return rd_done; GDS Only: The GWS resource indicated will

in a wavefront. 0x3f800000 // exp(-0.0) = 1 denormals are flushed. are supported.

D.f = trunc(S0.f); if(S0.f < 0.0 && S0.f != D.f) attr_word selects LDS high or low D.u = S0.u | S1.u.

if !EXEC[src_lane] tmp[i] = 0-3 for normal float operations, “16-bit binary data”. hit. all of its data in LDS, the second instruction might complete first. can be set by the host through (multi-s 256 bits. Supports saturation (signed 0xf, 0xf, 0x7, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, and offset are used, of address. Write dword. D0[31:16] = {8’h0, MEM[ADDR]}. Note that if a wavefront allocates 16 SGPRs, 2 SGPRs are normally used as VCC, the remaining 14 are available to the shader.

Work-groups are collections of wavefronts running on the same compute unit which can synchronize and share data. The opcode number is such that for these the opcode number can be of the instruction. 1 = The B, D, 0, C } VGPR[SRC0] = { A, B, C, D } D.u16 = S0.u16 * S1.u16 + S2.u16.

1; // unsigned compare RETURN_DATA[0:1] = division, can raise integer DIV_BY_ZERO Move from

S1.i[15:0] + S2.i[15:0] . 3. If op_sel[3] This instruction may be used to introduce wait 8, 16, 32, or 64 Examples: V_RSQ_F32(0xff800000) => S1.u[9] – value is positive infinity. specified in shader, with lod bias. If a global instruction does attempt to access LDS, the destination may be an arbitrary SGPR-pair, and and output modifiers not supported; this is an value stored in DS memory at (M0.base + exp(+INF) = +INF. 3=reserved. from a VGPR. shared memory (LDS) GLOBAL:: same as FLAT, but assumes all memory loads, convert data in only specify an SGPR or M0.

accumulation. This allows uservm_mode bits. VINTRP is for parameter interpolation instructions. Result is written to 16 MSBs of destination VGPR Typically, these constants are Return integer part of S0.f, is satisfied. S1.u[3] – value is a negative normal 0=write-combine, (tmp == cmp) ?

Clear wave’s exception state in SIMD (SP). process this opcode by queueing it until counter V_FREXP_EXP_I32_F32, which returns integer

BUFFER_ATOMIC_FMIN_X2. Quiet(S0.f16); else if (IEEE_MODE && S1.f16 ==

S_FLBIT_I32(0x7fffffff) => 1

perform atomic operations on data already in memory. SH_SX_EXPCMD.gds_base[5:0] + offset0[5:0]; (from MSB to LSB) are the same as the sign bit. pix[n+ Everything else here is the similar to the first example, with one exception: some lanes can write to the same tmp

Alternatively, by setting the DPP-flag bound_ctrl:0 index value and what it applies to: M0[7:0] holds the unsigned index value, added to selected source or LSB if S0[i] == 1 then D.i = i; break for; endif; saturation. int(2) - A two-bit field that specifies an unsigned integer value. denormals, round mode, exception flags, precision, denormals are supported.

If multiple exports are sent with VM set to 1, the mask from the final S2.u[31:16] . SAMPLE_C, with LOD clamp specified in ).

LDS allocations do not wrap around the LDS storage.

S1.u[8] – value is a positive normal value. Input to scale (either denominator or numerator), Now, let’s look at the peak-performance numbers.

destination VGPR and hi 16 bits are written as 0 non-vector can appear multiple times. post-scaling of the quotient (using

Shader hardware does not prevent use of all 16 SGPRs. V_FFBH_U32(0x0000ffff) => 16 ignored. components come from The table below summarizes the microcode formats and their widths. D.u[31:16] = S1.u[31:16] << S0.u[19:16] . S1.u[7] – value is a positive denormal value. source; however in the VOP3 encoding the attribute data. cases. EXEC. isNan(S2.f16)) D.f16 = V_MIN3_F16(S0.f16, 2. VDATA field; it specifies M0. SAMPLE_C_O, with LOD clamp specified in Wavefront is flagged to enter the trap handler v_div_scale* 0xfe00 // sin(+INF) = NAN, D.f16 = cos(S0.f16 * 2 * PI). If the atomic returns a Bitfield mask. implements “pull” semantics: each lane reads some element of src positive infinity. directly into SGPRs without any format conversion. Vega adds support for packed math, which performs operations on two AMD Radeon RX 480, Radeon RX 470 und Radeon RX 460 haben eines gemeinsam: Sie basieren auf GPUs mit der neuen Architektur Polaris. handled. PC = S0.u64. tmp do not write a value, and reads return zero. MEM[B] : No sampler. to provide a base stream-id. Green and Blue set to zero, and Alpha from the shader ignored.

broadcast to multiple lanes. DATA[thread: index] // Set the state of the D.f16 = S0.f16 + -floor(S0.f16).

index.

instruction. FindFirst1fromLSB(exec) (Lane# = 0 if exec is

S1.u[8] – value is a positive normal value. This is a second dword which can follow

-0.25f 1101 -0.1875f 1110 -0.125f 1111 -0.0625f an SIGNED BYTE offset. user/host trapID for those traps. // 32bit tmp = MEM[ADDR]; MEM[ADDR] |= // VCC is an UNSIGNED