instruction_set_extensions.rst

CORE-V Instruction Set Custom Extensions

CV32E40P supports the following CORE-V ISA X Custom Extensions, which can be enabled by setting COREV_PULP == 1.

• Post-Increment load and stores, see :ref:`corev_load_store`, invoked in the tool chain with -march=rv32i*_xcvmem.
• Hardware Loop extension, see :ref:`corev_hardware_loop`, invoked in the tool chain with -march=rv32i*_xcvhwlp.
• ALU extensions, see :ref:`corev_alu`, which are divided into three sub-extensions:
  • bit manipulation instructions, invoked in the tool chain with -march=rv32i*_xcvbitmanip;
  • miscellaneous ALU instructions, invoked in the tool chain with -march=rv32i*_xcvalu; and
  • immediate branch instructions, invoked in the tool chain with -march=rv32i*_xcvbi.
• Multiply-Accumulate extensions, see :ref:`corev_multiply_accumulate`, invoked in the tool chain with -march=rv32i*_xcvmac.
• Single Instruction Multiple Data (aka SIMD) extensions, see :ref:`corev_simd`, invoked in the tool chain with -march=rv32i*_xcvsimd.

Additionally the event load instruction (cv.elw) is supported by setting COREV_CLUSTER == 1, see :ref:`corev_event_load`. This is a separate ISA extension, invoked in the tool chain with -march=rv32i*_xcvelw.

If not specified, all the operands are signed and immediate values are sign-extended.

To use such instructions, you need to compile your SW with the CORE-V GCC or Clang/LLVM compiler.

Note

Clang/LLVM assembler will be supported by 30 June 2023, with builtin function support by 31 December 2023.

Pseudo-instructions

This specification also includes documentation of some CORE-V pseudo-instructions. Pseudo-instructions are implemented in the assembler that are similar to a base instruction but provides control information to the assembler as opposed to generating its base instruction. This makes it easier to program as we gain clarity on the intention of the programmer.

• 16-Bit x 16-Bit Multiplication pseudo-instructions, see :ref:`corev_16_bit_multiply_pseudo_instructions`.

Post-Increment Load & Store Instructions and Register-Register Load & Store Instructions

Post-Increment load and store instructions perform a load, or a store, respectively, while at the same time incrementing the address that was used for the memory access. Since it is a post-incrementing scheme, the base address is used for the access and the modified address is written back to the register-file. There are versions of those instructions that use immediates and those that use registers as offsets. The base address always comes from a register.

The custom post-increment load & store instructions and register-register load & store instructions are only supported if COREV_PULP == 1.

Load operations

Note

When same register is used as address and destination (rD == rs1) for post-incremented loads, loaded data has highest priority over incremented address when writing to this same register.

Load operations

Mnemonic	Description
Register-Immediate Loads with Post-Increment
cv.lb rD, (rs1), Imm	rD = Sext(Mem8(rs1)) rs1 += Sext(Imm[11:0])
cv.lbu rD, (rs1), Imm	rD = Zext(Mem8(rs1)) rs1 += Sext(Imm[11:0])
cv.lh rD, (rs1), Imm	rD = Sext(Mem16(rs1)) rs1 += Sext(Imm[11:0])
cv.lhu rD, (rs1), Imm	rD = Zext(Mem16(rs1)) rs1 += Sext(Imm[11:0])
cv.lw rD, (rs1), Imm	rD = Mem32(rs1) rs1 += Sext(Imm[11:0])
Register-Register Loads with Post-Increment
cv.lb rD, (rs1), rs2	rD = Sext(Mem8(rs1)) rs1 += rs2
cv.lbu rD, (rs1), rs2	rD = Zext(Mem8(rs1)) rs1 += rs2
cv.lh rD, (rs1), rs2	rD = Sext(Mem16(rs1)) rs1 += rs2
cv.lhu rD, (rs1), rs2	rD = Zext(Mem16(rs1)) rs1 += rs2
cv.lw rD, (rs1), rs2	rD = Mem32(rs1) rs1 += rs2
Register-Register Loads
cv.lb rD, rs2(rs1)	rD = Sext(Mem8(rs1 + rs2))
cv.lbu rD, rs2(rs1)	rD = Zext(Mem8(rs1 + rs2))
cv.lh rD, rs2(rs1)	rD = Sext(Mem16(rs1 + rs2))
cv.lhu rD, rs2(rs1)	rD = Zext(Mem16(rs1 + rs2))
cv.lw rD, rs2(rs1)	rD = Mem32(rs1 + rs2)

Store operations

Store operations

Mnemonic	Description
Register-Immediate Stores with Post-Increment
cv.sb rs2, (rs1), Imm	Mem8(rs1) = rs2 rs1 += Sext(Imm[11:0])
cv.sh rs2, (rs1), Imm	Mem16(rs1) = rs2 rs1 += Sext(Imm[11:0])
cv.sw rs2, (rs1), Imm	Mem32(rs1) = rs2 rs1 += Sext(Imm[11:0])
Register-Register Stores with Post-Increment
cv.sb rs2, (rs1), rs3	Mem8(rs1) = rs2 rs1 += rs3
cv.sh rs2, (rs1), rs3	Mem16(rs1) = rs2 rs1 += rs3
cv.sw rs2, (rs1), rs3	Mem32(rs1) = rs2 rs1 += rs3
Register-Register Stores
cv.sb rs2, rs3(rs1)	Mem8(rs1 + rs3) = rs2
cv.sh rs2 rs3(rs1)	Mem16(rs1 + rs3) = rs2
cv.sw rs2, rs3(rs1)	Mem32(rs1 + rs3) = rs2

Encoding

Post-Increment Register-Immediate Load operations encoding

31 : 20	19 : 15	14 : 12	11 : 7	6 : 0
imm[11:0]	rs1	funct3	rD	opcode	Mnemonic
offset	base	000	dest	000 1011	cv.lb rD, (rs1), Imm
offset	base	100	dest	000 1011	cv.lbu rD, (rs1), Imm
offset	base	001	dest	000 1011	cv.lh rD, (rs1), Imm
offset	base	101	dest	000 1011	cv.lhu rD, (rs1), Imm
offset	base	010	dest	000 1011	cv.lw rD, (rs1), Imm

Post-Increment Register-Register Load operations encoding

31 : 25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
funct7	rs2	rs1	funct3	rD	opcode	Mnemonic
000 0000	offset	base	011	dest	010 1011	cv.lb rD, (rs1), rs2
000 1000	offset	base	011	dest	010 1011	cv.lbu rD, (rs1), rs2
000 0001	offset	base	011	dest	010 1011	cv.lh rD, (rs1), rs2
000 1001	offset	base	011	dest	010 1011	cv.lhu rD, (rs1), rs2
000 0010	offset	base	011	dest	010 1011	cv.lw rD, (rs1), rs2

Register-Register Load operations encoding

31 : 25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
funct7	rs2	rs1	funct3	rD	opcode	Mnemonic
000 0100	offset	base	011	dest	010 1011	cv.lb rD, rs2(rs1)
000 1100	offset	base	011	dest	010 1011	cv.lbu rD, rs2(rs1)
000 0101	offset	base	011	dest	010 1011	cv.lh rD, rs2(rs1)
000 1101	offset	base	011	dest	010 1011	cv.lhu rD, rs2(rs1)
000 0110	offset	base	011	dest	010 1011	cv.lw rD, rs2(rs1)

Post-Increment Register-Immediate Store operations encoding

31 : 25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
imm[11:5]	rs2	rs1	funct3	imm[4:0]	opcode	Mnemonic
offset[11:5]	src	base	000	offset[4:0]	010 1011	cv.sb rs2, (rs1), Imm
offset[11:5]	src	base	001	offset[4:0]	010 1011	cv.sh rs2, (rs1), Imm
offset[11:5]	src	base	010	offset[4:0]	010 1011	cv.sw rs2, (rs1), Imm

Post-Increment Register-Register Store operations encoding

31 : 25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
funct7	rs2	rs1	funct3	rs3	opcode	Mnemonic
001 0000	src	base	011	offset	010 1011	cv.sb rs2, (rs1), rs3
001 0001	src	base	011	offset	010 1011	cv.sh rs2, (rs1), rs3
001 0010	src	base	011	offse t	010 1011	cv.sw rs2, (rs1), rs3

Register-Register Store operations encoding

31 : 25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
funct7	rs2	rs1	funct3	rs3	opcode	Mnemonic
001 0100	src	base	011	offset	010 1011	cv.sb rs2, rs3(rs1)
001 0101	src	base	011	offset	010 1011	cv.sh rs2, rs3(rs1)
001 0110	src	base	011	offset	010 1011	cv.sw rs2, rs3(rs1)

Event Load Instruction

The event load instruction cv.elw is only supported if the COREV_CLUSTER parameter is set to 1. The event load performs a load word and can cause the CV32E40P to enter a sleep state as explained in :ref:`pulp_cluster`.

Event Load operation

Event Load operation

Mnemonic	Description
Event Load
cv.elw rD, Imm(rs1)	rD = Mem32(Sext(Imm) + rs1)

Encoding

Event Load operation encoding

31 : 20	19 : 15	14 : 12	11 : 7	6 : 0
imm[11:0]	rs1	funct3	rD	opcode	Mnemonic
offset	base	011	dest	000 1011	cv.elw rD, Imm(rs1)

Hardware Loops

The loop has to be setup before entering the loop body. For this purpose, there are two methods, either the long commands that separately set start- and end-addresses of the loop and the number of iterations, or the short command that does all of this in a single instruction. The short command has a limited range for the number of instructions contained in the loop and the loop must start in the next instruction after the setup instruction.

Due to start/end addresses constraint, the 2 LSBs are hardwired to 0. When using cv.start and cv.end instructions, the 2 LSBs of rs1 are ignored.

Hardware loop instructions and related CSRs are only supported if COREV_PULP == 1.

Details about the hardware loop constraints are provided in :ref:`hwloop-specs`.

In the following tables, the hardware loop instructions are reported. In assembly, L is referred by 0 or 1.

Hardware Loops operations

Long Hardware Loop Setup operations

Mnemonic	Description
cv.starti L, uimmL	lpstart[L] = PC + (uimmL << 2)
cv.start L, rs1	lpstart[L] = rs1
cv.endi L, uimmL	lpend[L] = PC + (uimmL << 2)
cv.end L, rs1	lpend[L] = rs1
cv.counti L, uimmL	lpcount[L] = uimmL
cv.count L, rs1	lpcount[L] = rs1

Short Hardware Loop Setup operations

Mnemonic	Description
cv.setupi L, uimmL, uimmS	lpstart[L] = PC + 4 lpend[L] = PC + (uimmS << 2) lpcount[L] = uimmL
cv.setup L, rs1, uimmL	lpstart[L] = PC + 4 lpend[L] = PC + (uimmL << 2) lpcount[L] = rs1

Encoding

Hardware Loops operations encoding

31 : 20	19 : 15	14 : 12	11 : 8	7	6 : 0
uimmL[11:0]	rs1	funct3	funct4	L	opcode	Mnemonic
uimmL[11:0]	00000	100	0000	L	010 1011	cv.starti L, uimmL
0000 0000 0000	src1	100	0001	L	010 1011	cv.start L, rs1
uimmL[11:0]	00000	100	0010	L	010 1011	cv.endi L, uimmL
0000 0000 0000	src1	100	0011	L	010 1011	cv.end L, rs1
uimmL[11:0]	00000	100	0100	L	010 1011	cv.counti L, uimmL
0000 0000 0000	src1	100	0101	L	010 1011	cv.count L, rs1
uimmL[11:0]	uimmS[4:0]	100	0110	L	010 1011	cv.setupi L, uimmL, uimmS
uimmL[11:0]	src1	100	0111	L	010 1011	cv.setup L, rs1, uimmL

ALU

CV32E40P supports advanced ALU operations that allow to perform multiple instructions that are specified in the base instruction set in one single instruction and thus increases efficiency of the core. For example, those instructions include zero-/sign-extension instructions for 8-bit and 16-bit operands, simple bit manipulation/counting instructions and min/max/avg instructions. The ALU does also support saturating, clipping and normalizing instructions which make fixed-point arithmetic more efficient.

The custom ALU extensions are only supported if COREV_PULP == 1.

The custom extensions to the ALU are split into several subgroups that belong together.

• Bit manipulation instructions are useful to work on single bits or groups of bits within a word, see :ref:`corev_bit_manipulation`.
• General ALU instructions try to fuse common used sequences into a single instruction and thus increase the performance of small kernels that use those sequence, see :ref:`corev_general_alu`.
• Immediate branching instructions are useful to compare a register with an immediate value before taking or not a branch, see see :ref:`corev_immediate_branching`.

Extract, Insert, Clear and Set instructions have the following meaning:

• Extract Is3+1 or rs2[9:5]+1 bits from position Is2 or rs2[4:0] [and sign extend it]
• Insert Is3+1 or rs2[9:5]+1 bits at position Is2 or rs2[4:0]
• Clear Is3+1 or rs2[9:5]+1 bits at position Is2 or rs2[4:0]
• Set Is3+1 or rs2[9:5]+1 bits at position Is2 or rs2[4:0]

Bit Reverse Instruction

This section will describe the cv.bitrev instruction from a bit manipulation perspective without describing it's application as part of an FFT. The bit reverse instruction will reverse bits in groupings of 1, 2 or 3 bits. The number of grouped bits is described by Is3 as follows:

• 0 - reverse single bits
• 1 - reverse groups of 2 bits
• 2 - reverse groups of 3 bits

The number of bits that are reversed can be controlled by Is2. This will specify the number of bits that will be removed by a left shift prior to the reverse operation resulting in the 32-Is2 least significant bits of the input value being reversed and the Is2 most significant bits of the input value being thrown out.

What follows is a few examples.

cv.bitrev x18, x20, 0, 4 (groups of 1 bit; radix-2)

in:    0xC64A5933 11000110010010100101100100110011
shift: 0x64A59330 01100100101001011001001100110000
out:   0x0CC9A526 00001100110010011010010100100110

Swap pattern:
A B C D E F G H . . . . . . . . . . . . . . . . . . . . . . . .
0 1 1 0 0 1 0 0 1 0 1 0 0 1 0 1 1 0 0 1 0 0 1 1 0 0 1 1 0 0 0 0
. . . . . . . . . . . . . . . . . . . . . . . . H G F E D C B A
0 0 0 0 1 1 0 0 1 1 0 0 1 0 0 1 1 0 1 0 0 1 0 1 0 0 1 0 0 1 1 0

In this example the input value is first shifted by 4 (Is2). Each individual bit is reversed. For example, bits 31 and 0 are swapped, 30 and 1, etc.

cv.bitrev x18, x20, 1, 4 (groups of 2 bits; radix-4)

in:    0xC64A5933 11000110010010100101100100110011
shift: 0x64A59330 01100100101001011001001100110000
out:   0x0CC65A19 00001100110001100101101000011001

Swap pattern:
A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P
01 10 01 00 10 10 01 01 10 01 00 11 00 11 00 00
P  O  N  M  L  K  J  I  H  G  F  E  D  C  B  A
00 00 11 00 11 00 01 10 01 01 10 10 00 01 10 01

In this example the input value is first shifted by 4 (Is2). Each group of two bits are reversed. For example, bits 31 and 30 are swapped with 1 and 0 (retaining their position relative to each other), bits 29 and 28 are swapped with 3 and 2, etc.

cv.bitrev x18, x20, 2, 4 (groups of 3 bits; radix-8)

in:    0xC64A5933 11000110010010100101100100110011
shift: 0x64A59330 01100100101001011001001100110000
out:   0x216B244B 00100001011010110010010001001011

Swap pattern:
A   B   C   D   E   F   G   H   I   J
011 001 001 010 010 110 010 011 001 100 00
   J   I   H   G   F   E   D   C   B   A
00 100 001 011 010 110 010 010 001 001 011

In this last example the input value is first shifted by 4 (Is2). Each group of three bits are reversed. For example, bits 31, 30 and 29 are swapped with 4, 3 and 2 (retaining their position relative to each other), bits 28, 27 and 26 are swapped with 7, 6 and 5, etc. Notice in this example that bits 0 and 1 are lost and the result is shifted right by two with bits 31 and 30 being tied to zero. Also notice that when J (100) is swapped with A (011), the four most significant bits are no longer zero as in the other cases. This may not be desirable if the intention is to pack a specific number of grouped bits aligned to the least significant bit and zero extended into the result. In this case care should be taken to set Is2 appropriately.

Bit Manipulation operations

Bit Manipulation operations

Mnemonic	Description
cv.extract rD, rs1, Is3, Is2	rD = Sext(rs1[min(Is3+Is2,31):Is2]) Note: Sign extension is done over the MSB of the extracted part.
cv.extractu rD, rs1, Is3, Is2	rD = Zext(rs1[min(Is3+Is2,31):Is2])
cv.extractr rD, rs1, rs2	rD = Sext(rs1[min(rs2[9:5]+rs2[4:0],31):rs2[4:0]]) Note: Sign extension is done over the MSB of the extracted part.
cv.extractur rD, rs1, rs2	rD = Zext(rs1[min(rs2[9:5]+rs2[4:0],31):rs2[4:0]])
cv.insert rD, rs1, Is3, Is2	rD[min(Is3+Is2,31):Is2] = rs1[Is3-(max(Is3+Is2,31)-31):0] The rest of the bits of rD are untouched and keep their previous value. Is3 + Is2 must be < 32.
cv.insertr rD, rs1, rs2	rD[min(rs2[9:5]+rs2[4:0],31):rs2[4:0]] = rs1[rs2[9:5]-(max(rs2[9:5]+rs2[4:0],31)-31):0] The rest of the bits of rD are untouched and keep their previous value. Is3 + Is2 must be < 32.
cv.bclr rD, rs1, Is3, Is2	rD[min(Is3+Is2,31):Is2] bits set to 0 The rest of the bits of rD are passed through from rs1 and are not modified.
cv.bclrr rD, rs1, rs2	rD[min(rs2[9:5]+rs2[4:0],31):rs2[4:0]] bits set to 0 The rest of the bits of rD are passed through from rs1 and are not modified.
cv.bset rD, rs1, Is3, Is2	rD[min(Is3+Is2,31):Is2] bits set to 1 The rest of the bits of rD are passed through from rs1 and are not modified.
cv.bsetr rD, rs1, rs2	rD[min(rs2[9:5]+rs2[4:0],31):rs2[4:0]] bits set to 1 The rest of the bits of rD are passed through from rs1 and are not modified.
cv.ff1 rD, rs1	rD = bit position of the first bit set in rs1, starting from LSB. If bit 0 is set, rD will be 0. If only bit 31 is set, rD will be 31. If rs1 is 0, rD will be 32.
cv.fl1 rD, rs1	rD = bit position of the last bit set in rs1, starting from MSB. If bit 31 is set, rD will be 31. If only bit 0 is set, rD will be 0. If rs1 is 0, rD will be 32.
cv.clb rD, rs1	rD = count leading bits of rs1 Number of consecutive 1's or 0's starting from MSB. If rs1 is 0, rD will be 0. If rs1 is different than 0, returns (number - 1).
cv.cnt rD, rs1	rD = Population count of rs1 Number of bits set in rs1.
cv.ror rD, rs1, rs2	rD = RotateRight(rs1, rs2)
cv.bitrev rD, rs1, Is3, Is2	Given an input rs1 it returns a bit reversed representation assuming FFT on 2^Is2 points in Radix 2^(Is3+1). Is3 can be either 0 (radix-2), 1 (radix-4) or 2 (radix-8). Note: When Is3 = 3, instruction has the same bahavior as if it was 0 (radix-2).

Bit Manipulation Encoding

Immediate Bit Manipulation operations encoding

31: 30	29 : 25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
f2	Is3[4:0]	Is2[4:0]	rs1	funct3	rD	opcode	Mnemonic
00	Luimm5[4:0]	Luimm5[4:0]	src	000	dest	101 1011	cv.extract rD, rs1, Is3, Is2
01	Luimm5[4:0]	Luimm5[4:0]	src	000	dest	101 1011	cv.extractu rD, rs1, Is3, Is2
10	Luimm5[4:0]	Luimm5[4:0]	src	000	dest	101 1011	cv.insert rD, rs1, Is3, Is2
00	Luimm5[4:0]	Luimm5[4:0]	src	001	dest	101 1011	cv.bclr rD, rs1, Is3, Is2
01	Luimm5[4:0]	Luimm5[4:0]	src	001	dest	101 1011	cv.bset rD, rs1, Is3, Is2
11	000, Luimm2[1:0]	Luimm5[4:0]	src	001	dest	101 1011	cv.bitrev rD, rs1, Is3, Is2

Register Bit Manipulation operations encoding

31 : 25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
funct7	rs2	rs1	funct3	rD	opcode
001 1000	src2	src1	011	dest	010 1011	cv.extractr rD, rs1, rs2
001 1001	src2	src1	011	dest	010 1011	cv.extractur rD, rs1, rs2
001 1010	src2	src1	011	dest	010 1011	cv.insertr rD, rs1, rs2
001 1100	src2	src1	011	dest	010 1011	cv.bclrr rD, rs1, rs2
001 1101	src2	scr1	011	dest	010 1011	cv.bsetr rD, rs1, rs2
010 0000	src2	src1	011	dest	010 1011	cv.ror rD, rs1, rs2
010 0001	00000	src1	011	dest	010 1011	cv.ff1 rD, rs1
010 0010	00000	src1	011	dest	010 1011	cv.fl1 rD, rs1
010 0011	00000	src1	011	dest	010 1011	cv.clb rD, rs1
010 0100	00000	src1	011	dest	010 1011	cv.cnt rD, rs1

General ALU operations

General ALU operations

Mnemonic	Description
cv.abs rD, rs1	rD = rs1 < 0 ? -rs1 : rs1
cv.sle rD, rs1, rs2	rD = rs1 <= rs2 ? 1 : 0 Note: Comparison is signed.
cv.sleu rD, rs1, rs2	rD = rs1 <= rs2 ? 1 : 0 Note: Comparison is unsigned.
cv.min rD, rs1, rs2	rD = rs1 < rs2 ? rs1 : rs2 Note: Comparison is signed.
cv.minu rD, rs1, rs2	rD = rs1 < rs2 ? rs1 : rs2 Note: Comparison is unsigned.
cv.max rD, rs1, rs2	rD = rs1 < rs2 ? rs2 : rs1 Note: Comparison is signed.
cv.maxu rD, rs1, rs2	rD = rs1 < rs2 ? rs2 : rs1 Note: Comparison is unsigned.
cv.exths rD, rs1	rD = Sext(rs1[15:0])
cv.exthz rD, rs1	rD = Zext(rs1[15:0])
cv.extbs rD, rs1	rD = Sext(rs1[7:0])
cv.extbz rD, rs1	rD = Zext(rs1[7:0])
cv.clip rD, rs1, Is2	if rs1 <= -2^(Is2-1), rD = -2^(Is2-1), else if rs1 >= 2^(Is2-1)-1, rD = 2^(Is2-1)-1, else rD = rs1 Note: If Is2 is equal to 0, -2^(Is2-1) is equivalent to -1 while (2^(Is2-1)-1) is equivalent to 0.
cv.clipu rD, rs1, Is2	if rs1 <= 0, rD = 0, else if rs1 >= 2^(Is2-1)-1, rD = 2^(Is2-1)-1, else rD = rs1 Note: If Is2 is equal to 0, (2^(Is2-1)-1) is equivalent to 0.
cv.clipr rD, rs1, rs2	rs2' = rs2 & 0x7FFFFFFF if rs1 <= -(rs2'+1), rD = -(rs2'+1), else if rs1 >=rs2', rD = rs2', else rD = rs1
cv.clipur rD, rs1, rs2	rs2' = rs2 & 0x7FFFFFFF if rs1 <= 0, rD = 0, else if rs1 >= rs2', rD = rs2', else rD = rs1
cv.addN rD, rs1, rs2, Is3	rD = (rs1 + rs2) >>> Is3 Note: Arithmetic shift right. Setting Is3 to 1 replaces former cv.avg.
cv.adduN rD, rs1, rs2, Is3	rD = (rs1 + rs2) >> Is3 Note: Logical shift right. Setting Is3 to 1 replaces former cv.avgu.
cv.addRN rD, rs1, rs2, Is3	rD = (rs1 + rs2 + 2^(Is3-1)) >>> Is3 Note: Arithmetic shift right. If Is3 is equal to 0, 2^(Is3-1) is equivalent to 0.
cv.adduRN rD, rs1, rs2, Is3	rD = (rs1 + rs2 + 2^(Is3-1))) >> Is3 Note: Logical shift right. If Is3 is equal to 0, 2^(Is3-1) is equivalent to 0.
cv.subN rD, rs1, rs2, Is3	rD = (rs1 - rs2) >>> Is3 Note: Arithmetic shift right.
cv.subuN rD, rs1, rs2, Is3	rD = (rs1 - rs2) >> Is3 Note: Logical shift right.
cv.subRN rD, rs1, rs2, Is3	rD = (rs1 - rs2 + 2^(Is3-1)) >>> Is3 Note: Arithmetic shift right. If Is3 is equal to 0, 2^(Is3-1) is equivalent to 0.
cv.subuRN rD, rs1, rs2, Is3	rD = (rs1 - rs2 + 2^(Is3-1))) >> Is3 Note: Logical shift right. If Is3 is equal to 0, 2^(Is3-1) is equivalent to 0.
cv.addNr rD, rs1, rs2	rD = (rD + rs1) >>> rs2[4:0] Note: Arithmetic shift right.
cv.adduNr rD, rs1, rs2	rD = (rD + rs1) >> rs2[4:0] Note: Logical shift right.
cv.addRNr rD, rs1, rs2	rD = (rD + rs1 + 2^(rs2[4:0]-1)) >>> rs2[4:0] Note: Arithmetic shift right. If rs2[4:0] is equal to 0, 2^(rs2[4:0]-1) is equivalent to 0.
cv.adduRNr rD, rs1, rs2	rD = (rD + rs1 + 2^(rs2[4:0]-1))) >> rs2[4:0] Note: Logical shift right. If rs2[4:0] is equal to 0, 2^(rs2[4:0]-1) is equivalent to 0.
cv.subNr rD, rs1, rs2	rD = (rD - rs1) >>> rs2[4:0] Note: Arithmetic shift right.
cv.subuNr rD, rs1, rs2	rD = (rD - rs1) >> rs2[4:0] Note: Logical shift right.
cv.subRNr rD, rs1, rs2	rD = (rD - rs1+ 2^(rs2[4:0]-1)) >>> rs2[4:0] Note: Arithmetic shift right. If rs2[4:0] is equal to 0, 2^(rs2[4:0]-1) is equivalent to 0.
cv.subuRNr rD, rs1, rs2	rD = (rD - rs1+ 2^(rs2[4:0]-1))) >> rs2[4:0] Note: Logical shift right. If rs2[4:0] is equal to 0, 2^(rs2[4:0]-1) is equivalent to 0.

General ALU Encoding

General ALU operations encoding

31 : 25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
funct7	rs2	rs1	funct3	rD	opcode
010 1000	00000	src1	011	dest	010 1011	cv.abs rD, rs1
010 1001	src2	src1	011	dest	010 1011	cv.sle rD, rs1, rs2
010 1010	src2	src1	011	dest	010 1011	cv.sleu rD, rs1, rs2
010 1011	src2	src1	011	dest	010 1011	cv.min rD, rs1, rs2
010 1100	src2	src1	011	dest	010 1011	cv.minu rD, rs1, rs2
010 1101	src2	src1	011	dest	010 1011	cv.max rD, rs1, rs2
010 1110	src2	src1	011	dest	010 1011	cv.maxu rD, rs1, rs2
011 0000	00000	src1	011	dest	010 1011	cv.exths rD, rs1
011 0001	00000	src1	011	dest	010 1011	cv.exthz rD, rs1
011 0010	00000	src1	011	dest	010 1011	cv.extbs rD, rs1
011 0011	00000	src1	011	dest	010 1011	cv.extbz rD, rs1

General ALU operations encoding

31 : 25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
funct7	Is2[4:0]	rs1	funct3	rD	opcode
011 1000	Luimm5[4:0]	src1	011	dest	010 1011	cv.clip rD, rs1, Is2
011 1001	Luimm5[4:0]	src1	011	dest	010 1011	cv.clipu rD, rs1, Is2
011 1010	src2	src1	011	dest	010 1011	cv.clipr rD, rs1, rs2
011 1011	src2	src1	011	dest	010 1011	cv.clipur rD, rs1, rs2

General ALU operations encoding

31: 30	29 : 25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
f2	Is3[4:0]	rs2	rs1	funct3	rD	opcode
00	Luimm5[4:0]	src2	src1	010	dest	101 1011	cv.addN rD, rs1, rs2, Is3
01	Luimm5[4:0]	src2	src1	010	dest	101 1011	cv.adduN rD, rs1, rs2, Is3
10	Luimm5[4:0]	src2	src1	010	dest	101 1011	cv.addRN rD, rs1, rs2, Is3
11	Luimm5[4:0]	src2	src1	010	dest	101 1011	cv.adduRN rD, rs1, rs2, Is3
00	Luimm5[4:0]	src2	src1	011	dest	101 1011	cv.subN rD, rs1, rs2, Is3
01	Luimm5[4:0]	src2	src1	011	dest	101 1011	cv.subuN rD, rs1, rs2, Is3
10	Luimm5[4:0]	src2	src1	011	dest	101 1011	cv.subRN rD, rs1, rs2, Is3
11	Luimm5[4:0]	src2	src1	011	dest	101 1011	cv.subuRN rD, rs1, rs2, Is3

General ALU operations encoding

31 : 25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
funct7	Is3[4:0]	rs1	funct3	rD	opcode
100 0000	src2	src1	011	dest	010 1011	cv.addNr rD, rs1, rs2
100 0001	src2	src1	011	dest	010 1011	cv.adduNr rD, rs1, rs
100 0010	src2	src1	011	dest	010 1011	cv.addRNr rD, rs1, rs
100 0011	src2	src1	011	dest	010 1011	cv.adduRNr rD, rs1, rs2
100 0100	src2	src1	011	dest	010 1011	cv.subNr rD, rs1, rs2
100 0101	src2	src1	011	dest	010 1011	cv.subuNr rD, rs1, rs2
100 0110	src2	src1	011	dest	010 1011	cv.subRNr rD, rs1, rs2
100 0111	src2	src1	011	dest	010 1011	cv.subuRNr rD, rs1, rs2

Immediate Branching operations

Immediate Branching operations

Mnemonic	Description
cv.beqimm rs1, Imm5, Imm12	Branch to PC + (Imm12 << 1) if rs1 is equal to Imm5. Note: Imm5 is signed.
cv.bneimm rs1, Imm5, Imm12	Branch to PC + (Imm12 << 1) if rs1 is not equal to Imm5. Note: Imm5 is signed.

Immediate Branching Encoding

Immediate Branching encoding

31	30 : 25	24 : 20	19 : 15	14 : 12	11 : 8	7	6 : 0
Imm12[12]	Imm12[10:5]	Imm5	rs1	funct3	Imm12	Imm12	opcode
Imm12[12]	Imm12[10:5]	Imm5	src1	110	Imm12[4:1]	Imm12[11]	000 1011	cv.beqimm rs1, Imm5, Imm12
Imm12[12]	Imm12[10:5]	Imm5	src1	111	Imm12[4:1]	Imm12[11]	000 1011	cv.bneimm rs1, Imm5, Imm12

Multiply-Accumulate

CV32E40P supports custom extensions for multiply-accumulate and half-word multiplications with an optional post-multiplication shift.

The custom multiply-accumulate extensions are only supported if COREV_PULP == 1.

16-Bit x 16-Bit Multiplication operations

16-Bit x 16-Bit Multiplication operations

Mnemonic	Description
cv.muluN rD, rs1, rs2, Is3	rD[31:0] = (Zext(rs1[15:0]) * Zext(rs2[15:0])) >> Is3 Note: Logical shift right.
cv.mulhhuN rD, rs1, rs2, Is3	rD[31:0] = (Zext(rs1[31:16]) * Zext(rs2[31:16])) >> Is3 Note: Logical shift right.
cv.mulsN rD, rs1, rs2, Is3	rD[31:0] = (Sext(rs1[15:0]) * Sext(rs2[15:0])) >>> Is3 Note: Arithmetic shift right.
cv.mulhhsN rD, rs1, rs2, Is3	rD[31:0] = (Sext(rs1[31:16]) * Sext(rs2[31:16])) >>> Is3 Note: Arithmetic shift right.
cv.muluRN rD, rs1, rs2, Is3	rD[31:0] = (Zext(rs1[15:0]) * Zext(rs2[15:0]) + 2^(Is3-1)) >> Is3 Note: Logical shift right. If Is3 is equal to 0, 2^(Is3-1) is equivalent to 0.
cv.mulhhuRN rD, rs1, rs2, Is3	rD[31:0] = (Zext(rs1[31:16]) * Zext(rs2[31:16]) + 2^(Is3-1)) >> Is3 Note: Logical shift right. If Is3 is equal to 0, 2^(Is3-1) is equivalent to 0.
cv.mulsRN rD, rs1, rs2, Is3	rD[31:0] = (Sext(rs1[15:0]) * Sext(rs2[15:0]) + 2^(Is3-1)) >>> Is3 Note: Arithmetic shift right. If Is3 is equal to 0, 2^(Is3-1) is equivalent to 0.
cv.mulhhsRN rD, rs1, rs2, Is3	rD[31:0] = (Sext(rs1[31:16]) * Sext(rs2[31:16]) + 2^(Is3-1)) >>> Is3 Note: Arithmetic shift right. If Is3 is equal to 0, 2^(Is3-1) is equivalent to 0.

16-Bit x 16-Bit Multiplication pseudo-instructions

16-Bit x 16-Bit Multiplication pseudo-instructions

Mnemonic	Base Instruction	Description
cv.mulu rD, rs1, rs2	cv.muluN rD, rs1, rs2, 0	rD[31:0] = (Zext(rs1[15:0]) * Zext(rs2[15:0])) >> 0 Note: Logical shift right.
cv.mulhhu rD, rs1, rs2	cv.mulhhuN rD, rs1, rs2, 0	rD[31:0] = (Zext(rs1[31:16]) * Zext(rs2[31:16])) >> 0 Note: Logical shift right.
cv.muls rD, rs1, rs2	cv.mulsN rD, rs1, rs2, 0	rD[31:0] = (Sext(rs1[15:0]) * Sext(rs2[15:0])) >> 0 Note: Arithmetic shift right.
cv.mulhhs rD, rs1, rs2	cv.mulhhsN rD, rs1, rs2, 0	rD[31:0] = (Sext(rs1[31:16]) * Sext(rs2[31:16])) >> 0 Note: Arithmetic shift right.

16-Bit x 16-Bit Multiply-Accumulate operations

16-Bit x 16-Bit Multiply-Accumulate operations

Mnemonic	Description
cv.macuN rD, rs1, rs2, Is3	rD[31:0] = (Zext(rs1[15:0]) * Zext(rs2[15:0]) + rD) >> Is3 Note: Logical shift right.
cv.machhuN rD, rs1, rs2, Is3	rD[31:0] = (Zext(rs1[31:16]) * Zext(rs2[31:16]) + rD) >> Is3 Note: Logical shift right.
cv.macsN rD, rs1, rs2, Is3	rD[31:0] = (Sext(rs1[15:0]) * Sext(rs2[15:0]) + rD) >>> Is3 Note: Arithmetic shift right.
cv.machhsN rD, rs1, rs2, Is3	rD[31:0] = (Sext(rs1[31:16]) * Sext(rs2[31:16]) + rD) >>> Is3 Note: Arithmetic shift right.
cv.macuRN rD, rs1, rs2, Is3	rD[31:0] = (Zext(rs1[15:0]) * Zext(rs2[15:0]) + rD + 2^(Is3-1)) >> Is3 Note: Logical shift right. If Is3 is equal to 0, 2^(Is3-1) is equivalent to 0.
cv.machhuRN rD, rs1, rs2, Is3	rD[31:0] = (Zext(rs1[31:16]) * Zext(rs2[31:16]) + rD + 2^(Is3-1)) >> Is3 Note: Logical shift right. If Is3 is equal to 0, 2^(Is3-1) is equivalent to 0.
cv.macsRN rD, rs1, rs2, Is3	rD[31:0] = (Sext(rs1[15:0]) * Sext(rs2[15:0]) + rD + 2^(Is3-1)) >>> Is3 Note: Arithmetic shift right. If Is3 is equal to 0, 2^(Is3-1) is equivalent to 0.
cv.machhsRN rD, rs1, rs2, Is3	rD[31:0] = (Sext(rs1[31:16]) * Sext(rs2[31:16]) + rD + 2^(Is3-1)) >>> Is3 Note: Arithmetic shift right. If Is3 is equal to 0, 2^(Is3-1) is equivalent to 0.

32-Bit x 32-Bit Multiply-Accumulate operations

32-Bit x 32-Bit Multiply-Accumulate operations

Mnemonic	Description
cv.mac rD, rs1, rs2	rD = rD + rs1 * rs2
cv.msu rD, rs1, rs2	rD = rD - rs1 * rs2

Encoding

16-Bit x 16-Bit Multiplication encoding

31: 30	29 : 25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
f2	Is3[4:0]	rs2	rs1	funct3	rD	opcode
00	Luimm5[4:0]	src2	src1	101	dest	101 1011	cv.muluN rD, rs1, rs2, Is3
01	Luimm5[4:0]	src2	src1	101	dest	101 1011	cv.mulhhuN rD, rs1, rs2, Is3
00	Luimm5[4:0]	src2	src1	100	dest	101 1011	cv.mulsN rD, rs1, rs2, Is3
01	Luimm5[4:0]	src2	src1	100	dest	101 1011	cv.mulhhsN rD, rs1, rs2, Is3
10	Luimm5[4:0]	src2	src1	101	dest	101 1011	cv.muluRN rD, rs1, rs2, Is3
11	Luimm5[4:0]	src2	src1	101	dest	101 1011	cv.mulhhuRN rD, rs1, rs2, Is3
10	Luimm5[4:0]	src2	src1	100	dest	101 1011	cv.mulsRN rD, rs1, rs2, Is3
11	Luimm5[4:0]	src2	src1	100	dest	101 1011	cv.mulhhsRN rD, rs1, rs2, Is3

16-Bit x 16-Bit Multiply-Accumulate encoding

31: 30	29 : 25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
f2	Is3[4:0]	rs2	rs1	funct3	rD	opcode
00	Luimm5[4:0]	src2	src1	111	dest	101 1011	cv.macuN rD, rs1, rs2, Is3
01	Luimm5[4:0]	src2	src1	111	dest	101 1011	cv.machhuN rD, rs1, rs2, Is3
00	Luimm5[4:0]	src2	src1	110	dest	101 1011	cv.macsN rD, rs1, rs2, Is3
01	Luimm5[4:0]	src2	src1	110	dest	101 1011	cv.machhsN rD, rs1, rs2, Is3
10	Luimm5[4:0]	src2	src1	111	dest	101 1011	cv.macuRN rD, rs1, rs2, Is3
11	Luimm5[4:0]	src2	src1	111	dest	101 1011	cv.machhuRN rD, rs1, rs2, Is3
10	Luimm5[4:0]	src2	src1	110	dest	101 1011	cv.macsRN rD, rs1, rs2, Is3
11	Luimm5[4:0]	src2	src1	110	dest	101 1011	cv.machhsRN rD, rs1, rs2, Is3

32-Bit x 32-Bit Multiply-Accumulate encoding

31 : 25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
funct7	rs2	rs1	funct3	rD	opcode
100 1000	src2	src1	011	dest	010 1011	cv.mac rD, rs1, rs2
100 1001	src2	src1	011	dest	010 1011	cv.msu rD, rs1, rs2

SIMD

The SIMD instructions perform operations on multiple sub-word elements at the same time. This is done by segmenting the data path into smaller parts when 8- or 16-bit operations should be performed.

The custom SIMD extensions are only supported if COREV_PULP == 1.

Note

See the comments at the start of :ref:`custom-isa-extensions` on availability of the compiler tool chains. Support for SIMD will be primarily through assembly code and builtin functions, with no auto-vectorization and limited other optimization. Simple auto-vectorization (add, sub...) and optimization will be evaluated once a stable GCC toolchain is available.

SIMD instructions are available in two flavors:

• 8-Bit, to perform four operations on the 4 bytes inside a 32-bit word at the same time (.b)
• 16-Bit, to perform two operations on the 2 half-words inside a 32-bit word at the same time (.h)

All the operations are rounded to the specified bidwidth as for the original RISC-V arithmetic operations. This is described by the "and" operation with a MASK. No overflow or carry-out flags are generated as for the 32-bit operations.

Additionally, there are three modes that influence the second operand:

1. Normal mode, vector-vector operation. Both operands, from rs1 and rs2, are treated as vectors of bytes or half-words.

   e.g. cv.add.h x3,x2,x1 performs:

   x3[31:16] = x2[31:16] + x1[31:16]

   x3[15: 0] = x2[15: 0] + x1[15: 0]

2. Scalar replication mode (.sc), vector-scalar operation. Operand 1 is treated as a vector, while operand 2 is treated as a scalar and replicated two or four times to form a complete vector. The LSP is used for this purpose.

   e.g. cv.add.sc.h x3,x2,x1 performs:

   x3[31:16] = x2[31:16] + x1[15: 0]

   x3[15: 0] = x2[15: 0] + x1[15: 0]

3. Immediate scalar replication mode (.sci), vector-scalar operation. Operand 1 is treated as vector, while operand 2 is treated as a scalar and comes from a 6-bit immediate.

   The immediate is either sign- or zero-extended depending on the operation. If not specified, the immediate is sign-extended with the exception of all cv.shuffle* where it is always unsigned.

   e.g. cv.add.sci.h x3,x2,-22 performs:

   x3[31:16] = x2[31:16] + 0xFFEA

   x3[15: 0] = x2[15: 0] + 0xFFEA

And finally for all the SIMD Bit Manipulation instructions, Imm6 is zero-extended.

In the following tables, the index i ranges from 0 to 1 for 16-Bit operations and from 0 to 3 for 8-Bit operations:

• The index 0 is 15:0 for 16-Bit operations or 7:0 for 8-Bit operations.
• The index 1 is 31:16 for 16-Bit operations or 15:8 for 8-Bit operations.
• The index 2 is 23:16 for 8-Bit operations.
• The index 3 is 31:24 for 8-Bit operations.

And I5, I4, I3, I2, I1 and I0 respectively represent bits 5, 4, 3, 2, 1 and 0 of the immediate value.

SIMD ALU operations

SIMD ALU operations

Mnemonic	Description
cv.add[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = (rs1[i] + op2[i]) & {0xFFFF, 0xFF}
cv.sub[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = (rs1[i] - op2[i]) & {0xFFFF, 0xFF}
cv.avg[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = ((rs1[i] + op2[i]) & {0xFFFF, 0xFF}) >> 1 Note: Arithmetic right shift.
cv.avgu[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = ((rs1[i] + op2[i]) & {0xFFFF, 0xFF}) >> 1 Note: Immediate is zero-extended, shift is logical.
cv.min[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] < op2[i] ? rs1[i] : op2[i]
cv.minu[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] < op2[i] ? rs1[i] : op2[i] Note: Immediate is zero-extended, comparison is unsigned.
cv.max[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] > op2[i] ? rs1[i] : op2[i]
cv.maxu[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] > op2[i] ? rs1[i] : op2[i] Note: Immediate is zero-extended, comparison is unsigned.
cv.srl[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] >> op2[i] Note: Immediate is zero-extended, shift is logical. Only Imm6[3:0] and rs2[3:0] are used for .h instruction and Imm6[2:0] and rs2[2:0] for .b instruction. In .sci case, unused Imm6 bits must be set to 0.
cv.sra[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] >>> op2[i] Note: Immediate is zero-extended, shift is arithmetic. Only Imm6[3:0] and rs2[3:0] are used for .h instruction and Imm6[2:0] and rs2[2:0] for .b instruction. In .sci case, unused Imm6 bits must be set to 0.
cv.sll[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] << op2[i] Note: Immediate is zero-extended, shift is logical. Only Imm6[3:0] and rs2[3:0] are used for .h instruction and Imm6[2:0] and rs2[2:0] for .b instruction. In .sci case, unused Imm6 bits must be set to 0.
cv.or[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] | op2[i]
cv.xor[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] ^ op2[i]
cv.and[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] & op2[i]
cv.abs{.h,.b} rD, rs1	rD[i] = rs1[i] < 0 ? -rs1[i] : rs1[i]

SIMD Bit Manipulation operations

SIMD Bit Manipulation operations

Mnemonic	Description
cv.extract.h rD, rs1, Imm6	rD = Sext(rs1[I0*16+15:I0*16]) Note: Only Imm6[0] bit is used and other Imm6 bits must be set to 0.
cv.extract.b rD, rs1, Imm6	rD = Sext(rs1[(I1:I0)*8+7:(I1:I0)*8]) Note: Only Imm6[1:0] bits are used and other Imm6 bits must be set to 0.
cv.extractu.h rD, rs1, Imm6	rD = Zext(rs1[I0*16+15:I0*16]) Note: Only Imm6[0] bit is used and other Imm6 bits must be set to 0.
cv.extractu.b rD, rs1, Imm6	rD = Zext(rs1[(I1:I0)*8+7:(I1:I0)*8]) Note: Only Imm6[1:0] bits are used and other Imm6 bits must be set to 0.
cv.insert.h rD, rs1, Imm6	rD[I0*16+15:I0*16] = rs1[15:0] Note: The rest of the bits of rD are untouched and keep their previous value. Only Imm6[0] bit is used and other Imm6 bits must be set to 0.
cv.insert.b rD, rs1, Imm6	rD[(I1:I0)*8+7:(I1:I0)*8] = rs1[7:0] Note: The rest of the bits of rD are untouched and keep their previous value. Only Imm6[1:0] bits are used and other Imm6 bits must be set to 0.

SIMD Dot Product operations

SIMD Dot Product operations

Mnemonic	Description
cv.dotup[.sc,.sci].h rD, rs1, [rs2, Imm6]	rD = rs1[0] * op2[0] + rs1[1] * op2[1] Note: All operands are unsigned.
cv.dotup[.sc,.sci].b rD, rs1, [rs2, Imm6]	rD = rs1[0] * op2[0] + rs1[1] * op2[1] + rs1[2] * op2[2] + rs1[3] * op2[3] Note: All operands are unsigned.
cv.dotusp[.sc,.sci].h rD, rs1, [rs2, Imm6]	rD = rs1[0] * op2[0] + rs1[1] * op2[1] Note: rs1 is treated as unsigned, while op2 is treated as signed.
cv.dotusp[.sc,.sci].b rD, rs1, [rs2, Imm6]	rD = rs1[0] * op2[0] + rs1[1] * op2[1] + rs1[2] * op2[2] + rs1[3] * op2[3] Note: rs1 is treated as unsigned, while op2 is treated as signed.
cv.dotsp[.sc,.sci].h rD, rs1, [rs2, Imm6]	rD = rs1[0] * op2[0] + rs1[1] * op2[1] Note: All operands are signed.
cv.dotsp[.sc,.sci].b rD, rs1, [rs2, Imm6]	rD = rs1[0] * op2[0] + rs1[1] * op2[1] + rs1[2] * op2[2] + rs1[3] * op2[3] Note: All operands are signed.
cv.sdotup[.sc,.sci].h rD, rs1, [rs2, Imm6]	rD = rD + rs1[0] * op2[0] + rs1[1] * op2[1] Note: All operands are unsigned.
cv.sdotup[.sc,.sci].b rD, rs1, [rs2, Imm6]	rD = rD + rs1[0] * op2[0] + rs1[1] * op2[1] + rs1[2] * op2[2] + rs1[3] * op2[3] Note: All operands are unsigned.
cv.sdotusp[.sc,.sci].h rD, rs1, [rs2, Imm6]	rD = rD + rs1[0] * op2[0] + rs1[1] * op2[1] Note: rs1 is treated as unsigned while op2 is treated as signed.
cv.sdotusp[.sc,.sci].b rD, rs1, [rs2, Imm6]	rD = rD + rs1[0] * op2[0] + rs1[1] * op2[1] + rs1[2] * op2[2] + rs1[3] * op2[3] Note: rs1 is treated as unsigned while op2 is treated as signed.
cv.sdotsp[.sc,.sci].h rD, rs1, [rs2, Imm6]	rD = rD + rs1[0] * op2[0] + rs1[1] * op2[1] Note: All operands are signed.
cv.sdotsp[.sc,.sci].b rD, rs1, [rs2, Imm6]	rD = rD + rs1[0] * op2[0] + rs1[1] * op2[1] + rs1[2] * op2[2] + rs1[3] * op2[3] Note: All operands are signed.

SIMD Shuffle and Pack operations

SIMD Shuffle and Pack operations

Mnemonic	Description
cv.shuffle.h rD, rs1, rs2	rD[31:16] = rs1[rs2[16]*16+15:rs2[16]*16] rD[15:0] = rs1[rs2[0]*16+15:rs2[0]*16]
cv.shuffle.sci.h rD, rs1, Imm6	rD[31:16] = rs1[I1*16+15:I1*16] rD[15:0] = rs1[I0*16+15:I0*16] Note: Only Imm6[1:0] bits are used and other Imm6 bits must be set to 0.
cv.shuffle.b rD, rs1, rs2	rD[31:24] = rs1[rs2[25:24]*8+7:rs2[25:24]*8] rD[23:16] = rs1[rs2[17:16]*8+7:rs2[17:16]*8] rD[15:8] = rs1[rs2[9:8]*8+7:rs2[9:8]*8] rD[7:0] = rs1[rs2[1:0]*8+7:rs2[1:0]*8]
cv.shuffleI0.sci.b rD, rs1, Imm6	rD[31:24] = rs1[7:0] rD[23:16] = rs1[(I5:I4)*8+7: (I5:I4)*8] rD[15:8] = rs1[(I3:I2)*8+7: (I3:I2)*8] rD[7:0] = rs1[(I1:I0)*8+7:(I1:I0)*8]
cv.shuffleI1.sci.b rD, rs1, Imm6	rD[31:24] = rs1[15:8] rD[23:16] = rs1[(I5:I4)*8+7: (I5:I4)*8] rD[15:8] = rs1[(I3:I2)*8+7: (I3:I2)*8] rD[7:0] = rs1[(I1:I0)*8+7:(I1:I0)*8]
cv.shuffleI2.sci.b rD, rs1, Imm6	rD[31:24] = rs1[23:16] rD[23:16] = rs1[(I5:I4)*8+7: (I5:I4)*8] rD[15:8] = rs1[(I3:I2)*8+7: (I3:I2)*8] rD[7:0] = rs1[(I1:I0)*8+7:(I1:I0)*8]
cv.shuffleI3.sci.b rD, rs1, Imm6	rD[31:24] = rs1[31:24] rD[23:16] = rs1[(I5:I4)*8+7: (I5:I4)*8] rD[15:8] = rs1[(I3:I2)*8+7: (I3:I2)*8] rD[7:0] = rs1[(I1:I0)*8+7:(I1:I0)*8]
cv.shuffle2.h rD, rs1, rs2	rD[31:16] = ((rs2[17] == 1) ? rs1 : rD)[rs2[16]*16+15:rs2[16]*16] rD[15:0] = ((rs2[1] == 1) ? rs1 : rD)[rs2[0]*16+15:rs2[0]*16]
cv.shuffle2.b rD, rs1, rs2	rD[31:24] = ((rs2[26] == 1) ? rs1 : rD)[rs2[25:24]*8+7:rs2[25:24]*8] rD[23:16] = ((rs2[18] == 1) ? rs1 : rD)[rs2[17:16]*8+7:rs2[17:16]*8] rD[15:8] = ((rs2[10] == 1) ? rs1 : rD)[rs2[9:8]*8+7:rs2[9:8]*8] rD[7:0] = ((rs2[2] == 1) ? rs1 : rD)[rs2[1:0]*8+7:rs2[1:0]*8]
cv.pack rD, rs1, rs2	rD[31:16] = rs1[15:0] rD[15:0] = rs2[15:0]
cv.pack.h rD, rs1, rs2	rD[31:16] = rs1[31:16] rD[15:0] = rs2[31:16]
cv.packhi.b rD, rs1, rs2	rD[31:24] = rs1[7:0] rD[23:16] = rs2[7:0] Note: The rest of the bits of rD are untouched and keep their previous value.
cv.packlo.b rD, rs1, rs2	rD[15:8] = rs1[7:0] rD[7:0] = rs2[7:0] Note: The rest of the bits of rD are untouched and keep their previous value.

SIMD ALU Encoding

SIMD ALU encoding

31 : 27	26	25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
funct5	F		rs2	rs1	funct3	rD	opcode
0 0000	0	0	src2	src1	000	dest	111 1011	cv.add.h rD, rs1, rs2
0 0000	0	0	src2	src1	100	dest	111 1011	cv.add.sc.h rD, rs1, rs2
0 0000	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.add.sci.h rD, rs1, Imm6
0 0000	0	0	src2	src1	001	dest	111 1011	cv.add.b rD, rs1, rs2
0 0000	0	0	src2	src1	101	dest	111 1011	cv.add.sc.b rD, rs1, rs2
0 0000	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.add.sci.b rD, rs1, Imm6
0 0001	0	0	src2	src1	000	dest	111 1011	cv.sub.h rD, rs1, rs2
0 0001	0	0	src2	src1	100	dest	111 1011	cv.sub.sc.h rD, rs1, rs2
0 0001	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.sub.sci.h rD, rs1, Imm6
0 0001	0	0	src2	src1	001	dest	111 1011	cv.sub.b rD, rs1, rs2
0 0001	0	0	src2	src1	101	dest	111 1011	cv.sub.sc.b rD, rs1, rs2
0 0001	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.sub.sci.b rD, rs1, Imm6
0 0010	0	0	src2	src1	000	dest	111 1011	cv.avg.h rD, rs1, rs2
0 0010	0	0	src2	src1	100	dest	111 1011	cv.avg.sc.h rD, rs1, rs2
0 0010	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.avg.sci.h rD, rs1, Imm6
0 0010	0	0	src2	src1	001	dest	111 1011	cv.avg.b rD, rs1, rs2
0 0010	0	0	src2	src1	101	dest	111 1011	cv.avg.sc.b rD, rs1, rs2
0 0010	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.avg.sci.b rD, rs1, Imm6
0 0011	0	0	src2	src1	000	dest	111 1011	cv.avgu.h rD, rs1, rs2
0 0011	0	0	src2	src1	100	dest	111 1011	cv.avgu.sc.h rD, rs1, rs2
0 0011	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.avgu.sci.h rD, rs1, Imm6
0 0011	0	0	src2	src1	001	dest	111 1011	cv.avgu.b rD, rs1, rs2
0 0011	0	0	src2	src1	101	dest	111 1011	cv.avgu.sc.b rD, rs1, rs2
0 0011	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.avgu.sci.b rD, rs1, Imm6
0 0100	0	0	src2	src1	000	dest	111 1011	cv.min.h rD, rs1, rs2
0 0100	0	0	src2	src1	100	dest	111 1011	cv.min.sc.h rD, rs1, rs2
0 0100	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.min.sci.h rD, rs1, Imm6
0 0100	0	0	src2	src1	001	dest	111 1011	cv.min.b rD, rs1, rs2
0 0100	0	0	src2	src1	101	dest	111 1011	cv.min.sc.b rD, rs1, rs2
0 0100	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.min.sci.b rD, rs1, Imm6
0 0101	0	0	src2	src1	000	dest	111 1011	cv.minu.h rD, rs1, rs2
0 0101	0	0	src2	src1	100	dest	111 1011	cv.minu.sc.h rD, rs1, rs2
0 0101	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.minu.sci.h rD, rs1, Imm6
0 0101	0	0	src2	src1	001	dest	111 1011	cv.minu.b rD, rs1, rs2
0 0101	0	0	src2	src1	101	dest	111 1011	cv.minu.sc.b rD, rs1, rs2
0 0101	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.minu.sci.b rD, rs1, Imm6
0 0110	0	0	src2	src1	000	dest	111 1011	cv.max.h rD, rs1, rs2
0 0110	0	0	src2	src1	100	dest	111 1011	cv.max.sc.h rD, rs1, rs2
0 0110	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.max.sci.h rD, rs1, Imm6
0 0110	0	0	src2	src1	001	dest	111 1011	cv.max.b rD, rs1, rs2
0 0110	0	0	src2	src1	101	dest	111 1011	cv.max.sc.b rD, rs1, rs2
0 0110	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.max.sci.b rD, rs1, Imm6
0 0111	0	0	src2	src1	000	dest	111 1011	cv.maxu.h rD, rs1, rs2
0 0111	0	0	src2	src1	100	dest	111 1011	cv.maxu.sc.h rD, rs1, rs2
0 0111	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.maxu.sci.h rD, rs1, Imm6
0 0111	0	0	src2	src1	001	dest	111 1011	cv.maxu.b rD, rs1, rs2
0 0111	0	0	src2	src1	101	dest	111 1011	cv.maxu.sc.b rD, rs1, rs2
0 0111	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.maxu.sci.b rD, rs1, Imm6
0 1000	0	0	src2	src1	000	dest	111 1011	cv.srl.h rD, rs1, rs2
0 1000	0	0	src2	src1	100	dest	111 1011	cv.srl.sc.h rD, rs1, rs2
0 1000	0	Imm6[0] 00 Imm6[3:1]		src1	110	dest	111 1011	cv.srl.sci.h rD, rs1, Imm6
0 1000	0	0	src2	src1	001	dest	111 1011	cv.srl.b rD, rs1, rs2
0 1000	0	0	src2	src1	101	dest	111 1011	cv.srl.sc.b rD, rs1, rs2
0 1000	0	Imm6[0] 000 Imm6[2:1]		src1	111	dest	111 1011	cv.srl.sci.b rD, rs1, Imm6
0 1001	0	0	src2	src1	000	dest	111 1011	cv.sra.h rD, rs1, rs2
0 1001	0	0	src2	src1	100	dest	111 1011	cv.sra.sc.h rD, rs1, rs2
0 1001	0	Imm6[0] 00 Imm6[3:1]		src1	110	dest	111 1011	cv.sra.sci.h rD, rs1, Imm6
0 1001	0	0	src2	src1	001	dest	111 1011	cv.sra.b rD, rs1, rs2
0 1001	0	0	src2	src1	101	dest	111 1011	cv.sra.sc.b rD, rs1, rs2
0 1001	0	Imm6[0] 000 Imm6[2:1]		src1	111	dest	111 1011	cv.sra.sci.b rD, rs1, Imm6
0 1010	0	0	src2	src1	000	dest	111 1011	cv.sll.h rD, rs1, rs2
0 1010	0	0	src2	src1	100	dest	111 1011	cv.sll.sc.h rD, rs1, rs2
0 1010	0	Imm6[0] 00 Imm6[3:1]		src1	110	dest	111 1011	cv.sll.sci.h rD, rs1, Imm6
0 1010	0	0	src2	src1	001	dest	111 1011	cv.sll.b rD, rs1, rs2
0 1010	0	0	src2	src1	101	dest	111 1011	cv.sll.sc.b rD, rs1, rs2
0 1010	0	Imm6[0] 000 Imm6[2:1]		src1	111	dest	111 1011	cv.sll.sci.b rD, rs1, Imm6
0 1011	0	0	src2	src1	000	dest	111 1011	cv.or.h rD, rs1, rs2
0 1011	0	0	src2	src1	100	dest	111 1011	cv.or.sc.h rD, rs1, rs2
0 1011	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.or.sci.h rD, rs1, Imm6
0 1011	0	0	src2	src1	001	dest	111 1011	cv.or.b rD, rs1, rs2
0 1011	0	0	src2	src1	101	dest	111 1011	cv.or.sc.b rD, rs1, rs2
0 1011	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.or.sci.b rD, rs1, Imm6
0 1100	0	0	src2	src1	000	dest	111 1011	cv.xor.h rD, rs1, rs2
0 1100	0	0	src2	src1	100	dest	111 1011	cv.xor.sc.h rD, rs1, rs2
0 1100	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.xor.sci.h rD, rs1, Imm6
0 1100	0	0	src2	src1	001	dest	111 1011	cv.xor.b rD, rs1, rs2
0 1100	0	0	src2	src1	101	dest	111 1011	cv.xor.sc.b rD, rs1, rs2
0 1100	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.xor.sci.b rD, rs1, Imm6
0 1101	0	0	src2	src1	000	dest	111 1011	cv.and.h rD, rs1, rs2
0 1101	0	0	src2	src1	100	dest	111 1011	cv.and.sc.h rD, rs1, rs2
0 1101	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.and.sci.h rD, rs1, Imm6
0 1101	0	0	src2	src1	001	dest	111 1011	cv.and.b rD, rs1, rs2
0 1101	0	0	src2	src1	101	dest	111 1011	cv.and.sc.b rD, rs1, rs2
0 1101	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.and.sci.b rD, rs1, Imm6
0 1110	0	0	0	src1	000	dest	111 1011	cv.abs.h rD, rs1
0 1110	0	0	0	src1	001	dest	111 1011	cv.abs.b rD, rs1
1 0111	0	Imm6[0] 00000		src1	000	dest	111 1011	cv.extract.h rD, rs1, Imm6
1 0111	0	Imm6[0] 0000 Imm6[1]		src1	001	dest	111 1011	cv.extract.b rD, rs1, Imm6
1 0111	0	Imm6[0] 00000		src1	010	dest	111 1011	cv.extractu.h rD, rs1, Imm6
1 0111	0	Imm6[0] 0000 Imm6[1]		src1	011	dest	111 1011	cv.extractu.b rD, rs1, Imm6
1 0111	0	Imm6[0] 00000		src1	100	dest	111 1011	cv.insert.h rD, rs1, Imm6
1 0111	0	Imm6[0] 0000 Imm6[1]		src1	101	dest	111 1011	cv.insert.b rD, rs1, Imm6
1 0000	0	0	src2	src1	000	dest	111 1011	cv.dotup.h rD, rs1, rs2
1 0000	0	0	src2	src1	100	dest	111 1011	cv.dotup.sc.h rD, rs1, rs2
1 0000	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.dotup.sci.h rD, rs1, Imm6
1 0000	0	0	src2	src1	001	dest	111 1011	cv.dotup.b rD, rs1, rs2
1 0000	0	0	src2	src1	101	dest	111 1011	cv.dotup.sc.b rD, rs1, rs2
1 0000	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.dotup.sci.b rD, rs1, Imm6
1 0001	0	0	src2	src1	000	dest	111 1011	cv.dotusp.h rD, rs1, rs2
1 0001	0	0	src2	src1	100	dest	111 1011	cv.dotusp.sc.h rD, rs1, rs2
1 0001	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.dotusp.sci.h rD, rs1, Imm6
1 0001	0	0	src2	src1	001	dest	111 1011	cv.dotusp.b rD, rs1, rs2
1 0001	0	0	src2	src1	101	dest	111 1011	cv.dotusp.sc.b rD, rs1, rs2
1 0001	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.dotusp.sci.b rD, rs1, Imm6
1 0010	0	0	src2	src1	000	dest	111 1011	cv.dotsp.h rD, rs1, rs2
1 0010	0	0	src2	src1	100	dest	111 1011	cv.dotsp.sc.h rD, rs1, rs2
1 0010	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.dotsp.sci.h rD, rs1, Imm6
1 0010	0	0	src2	src1	001	dest	111 1011	cv.dotsp.b rD, rs1, rs2
1 0010	0	0	src2	src1	101	dest	111 1011	cv.dotsp.sc.b rD, rs1, rs2
1 0010	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.dotsp.sci.b rD, rs1, Imm6
1 0011	0	0	src2	src1	000	dest	111 1011	cv.sdotup.h rD, rs1, rs2
1 0011	0	0	src2	src1	100	dest	111 1011	cv.sdotup.sc.h rD, rs1, rs2
1 0011	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.sdotup.sci.h rD, rs1, Imm6
1 0011	0	0	src2	src1	001	dest	111 1011	cv.sdotup.b rD, rs1, rs2
1 0011	0	0	src2	src1	101	dest	111 1011	cv.sdotup.sc.b rD, rs1, rs2
1 0011	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.sdotup.sci.b rD, rs1, Imm6
1 0100	0	0	src2	src1	000	dest	111 1011	cv.sdotusp.h rD, rs1, rs2
1 0100	0	0	src2	src1	100	dest	111 1011	cv.sdotusp.sc.h rD, rs1, rs2
1 0100	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.sdotusp.sci.h rD, rs1, Imm6
1 0100	0	0	src2	src1	001	dest	111 1011	cv.sdotusp.b rD, rs1, rs2
1 0100	0	0	src2	src1	101	dest	111 1011	cv.sdotusp.sc.b rD, rs1, rs2
1 0100	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.sdotusp.sci.b rD, rs1, Imm6
1 0101	0	0	src2	src1	000	dest	111 1011	cv.sdotsp.h rD, rs1, rs2
1 0101	0	0	src2	src1	100	dest	111 1011	cv.sdotsp.sc.h rD, rs1, rs2
1 0101	0	Imm6[0|5:1]		src1	110	dest	111 1011	cv.sdotsp.sci.h rD, rs1, Imm6
1 0101	0	0	src2	src1	001	dest	111 1011	cv.sdotsp.b rD, rs1, rs2
1 0101	0	0	src2	src1	101	dest	111 1011	cv.sdotsp.sc.b rD, rs1, rs2
1 0101	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.sdotsp.sci.b rD, rs1, Imm6
1 1000	0	0	src2	src1	000	dest	111 1011	cv.shuffle.h rD, rs1, rs2
1 1000	0	Imm6[0] 0000 Imm6[1]		src1	110	dest	111 1011	cv.shuffle.sci.h rD, rs1, Imm6
1 1000	0	0	src2	src1	001	dest	111 1011	cv.shuffle.b rD, rs1, rs2
1 1000	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.shuffleI0.sci.b rD, rs1, Imm6
1 1001	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.shuffleI1.sci.b rD, rs1, Imm6
1 1010	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.shuffleI2.sci.b rD, rs1, Imm6
1 1011	0	Imm6[0|5:1]		src1	111	dest	111 1011	cv.shuffleI3.sci.b rD, rs1, Imm6
1 1100	0	0	src2	src1	000	dest	111 1011	cv.shuffle2.h rD, rs1, rs2
1 1100	0	0	src2	src1	001	dest	111 1011	cv.shuffle2.b rD, rs1, rs2
1 1110	0	0	src2	src1	000	dest	111 1011	cv.pack rD, rs1, rs2
1 1110	0	1	src2	src1	000	dest	111 1011	cv.pack.h rD, rs1, rs2
1 1111	0	1	src2	src1	001	dest	111 1011	cv.packhi.b rD, rs1, rs2
1 1111	0	0	src2	src1	001	dest	111 1011	cv.packlo.b rD, rs1, rs2

SIMD Comparison operations

SIMD comparisons are done on individual bytes (.b) or half-words (.h), depending on the chosen mode. If the comparison result is true, all bits in the corresponding byte/half-word are set to 1. If the comparison result is false, all bits are set to 0.

The default mode (no .sc, .sci) compares the lowest byte/half-word of the first operand with the lowest byte/half-word of the second operand, and so on. If the mode is set to scalar replication (.sc), always the lowest byte/half-word of the second operand is used for comparisons, thus instead of a vector comparison a scalar comparison is performed. In the immediate scalar replication mode (.sci), the immediate given to the instruction is used for the comparison.

SIMD Comparison operations

Mnemonic	Description
cv.cmpeq[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] == op2 ? '1 : '0
cv.cmpne[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] != op2 ? '1 : '0
cv.cmpgt[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] > op2 ? '1 : '0
cv.cmpge[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] >=op2 ? '1 : '0
cv.cmplt[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] < op2 ? '1 : '0
cv.cmple[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] <= op2 ? '1 : '0
cv.cmpgtu[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] > op2 ? '1 : '0 Note: Unsigned comparison.
cv.cmpgeu[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] >= op2 ? '1 : '0 Note: Unsigned comparison.
cv.cmpltu[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] < op2 ? '1 : '0 Note: Unsigned comparison.
cv.cmpleu[.sc,.sci]{.h,.b} rD, rs1, [rs2, Imm6]	rD[i] = rs1[i] <= op2 ? '1 : '0 Note: Unsigned comparison.

SIMD Comparison Encoding

SIMD Comparison encoding

31 : 27	26	25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
funct5	F		rs2	rs1	funct3	rD	opcode
0 0000	1	0	src2	src1	000	dest	111 1011	cv.cmpeq.h rD, rs1, rs2
0 0000	1	0	src2	src1	100	dest	111 1011	cv.cmpeq.sc.h rD, rs1, rs2
0 0000	1	Imm6[0|5:1]		src1	110	dest	111 1011	cv.cmpeq.sci.h rD, rs1, Imm6
0 0000	1	0	src2	src1	001	dest	111 1011	cv.cmpeq.b rD, rs1, rs2
0 0000	1	0	src2	src1	101	dest	111 1011	cv.cmpeq.sc.b rD, rs1, rs2
0 0000	1	Imm6[0|5:1]		src1	111	dest	111 1011	cv.cmpeq.sci.b rD, rs1, Imm6
0 0001	1	0	src2	src1	000	dest	111 1011	cv.cmpne.h rD, rs1, rs2
0 0001	1	0	src2	src1	100	dest	111 1011	cv.cmpne.sc.h rD, rs1, rs2
0 0001	1	Imm6[0|5:1]		src1	110	dest	111 1011	cv.cmpne.sci.h rD, rs1, Imm6
0 0001	1	0	src2	src1	001	dest	111 1011	cv.cmpne.b rD, rs1, rs2
0 0001	1	0	src2	src1	101	dest	111 1011	cv.cmpne.sc.b rD, rs1, rs2
0 0001	1	Imm6[0|5:1]		src1	111	dest	111 1011	cv.cmpne.sci.b rD, rs1, Imm6
0 0010	1	0	src2	src1	000	dest	111 1011	cv.cmpgt.h rD, rs1, rs2
0 0010	1	0	src2	src1	100	dest	111 1011	cv.cmpgt.sc.h rD, rs1, rs2
0 0010	1	Imm6[0|5:1]		src1	110	dest	111 1011	cv.cmpgt.sci.h rD, rs1, Imm6
0 0010	1	0	src2	src1	001	dest	111 1011	cv.cmpgt.b rD, rs1, rs2
0 0010	1	0	src2	src1	101	dest	111 1011	cv.cmpgt.sc.b rD, rs1, rs2
0 0010	1	Imm6[0|5:1]		src1	111	dest	111 1011	cv.cmpgt.sci.b rD, rs1, Imm6
0 0011	1	0	src2	src1	000	dest	111 1011	cv.cmpge.h rD, rs1, rs2
0 0011	1	0	src2	src1	100	dest	111 1011	cv.cmpge.sc.h rD, rs1, rs2
0 0011	1	Imm6[0|5:1]		src1	110	dest	111 1011	cv.cmpge.sci.h rD, rs1, Imm6
0 0011	1	0	src2	src1	001	dest	111 1011	cv.cmpge.b rD, rs1, rs2
0 0011	1	0	src2	src1	101	dest	111 1011	cv.cmpge.sc.b rD, rs1, rs2
0 0011	1	Imm6[0|5:1]		src1	111	dest	111 1011	cv.cmpge.sci.b rD, rs1, Imm6
0 0100	1	0	src2	src1	000	dest	111 1011	cv.cmplt.h rD, rs1, rs2
0 0100	1	0	src2	src1	100	dest	111 1011	cv.cmplt.sc.h rD, rs1, rs2
0 0100	1	Imm6[0|5:1]		src1	110	dest	111 1011	cv.cmplt.sci.h rD, rs1, Imm6
0 0100	1	0	src2	src1	001	dest	111 1011	cv.cmplt.b rD, rs1, rs2
0 0100	1	0	src2	src1	101	dest	111 1011	cv.cmplt.sc.b rD, rs1, rs2
0 0100	1	Imm6[0|5:1]		src1	111	dest	111 1011	cv.cmplt.sci.b rD, rs1, Imm6
0 0101	1	0	src2	src1	000	dest	111 1011	cv.cmple.h rD, rs1, rs2
0 0101	1	0	src2	src1	100	dest	111 1011	cv.cmple.sc.h rD, rs1, rs2
0 0101	1	Imm6[0|5:1]		src1	110	dest	111 1011	cv.cmple.sci.h rD, rs1, Imm6
0 0101	1	0	src2	src1	001	dest	111 1011	cv.cmple.b rD, rs1, rs2
0 0101	1	0	src2	src1	101	dest	111 1011	cv.cmple.sc.b rD, rs1, rs2
0 0101	1	Imm6[0|5:1]		src1	111	dest	111 1011	cv.cmple.sci.b rD, rs1, Imm6
0 0110	1	0	src2	src1	000	dest	111 1011	cv.cmpgtu.h rD, rs1, rs2
0 0110	1	0	src2	src1	100	dest	111 1011	cv.cmpgtu.sc.h rD, rs1, rs2
0 0110	1	Imm6[0|5:1]		src1	110	dest	111 1011	cv.cmpgtu.sci.h rD, rs1, Imm6
0 0110	1	0	src2	src1	001	dest	111 1011	cv.cmpgtu.b rD, rs1, rs2
0 0110	1	0	src2	src1	101	dest	111 1011	cv.cmpgtu.sc.b rD, rs1, rs2
0 0110	1	Imm6[0|5:1]		src1	111	dest	111 1011	cv.cmpgtu.sci.b rD, rs1, Imm6
0 0111	1	0	src2	src1	000	dest	111 1011	cv.cmpgeu.h rD, rs1, rs2
0 0111	1	0	src2	src1	100	dest	111 1011	cv.cmpgeu.sc.h rD, rs1, rs2
0 0111	1	Imm6[0|5:1]		src1	110	dest	111 1011	cv.cmpgeu.sci.h rD, rs1, Imm6
0 0111	1	0	src2	src1	001	dest	111 1011	cv.cmpgeu.b rD, rs1, rs2
0 0111	1	0	src2	src1	101	dest	111 1011	cv.cmpgeu.sc.b rD, rs1, rs2
0 0111	1	Imm6[0|5:1]		src1	111	dest	111 1011	cv.cmpgeu.sci.b rD, rs1, Imm6
0 1000	1	0	src2	src1	000	dest	111 1011	cv.cmpltu.h rD, rs1, rs2
0 1000	1	0	src2	src1	100	dest	111 1011	cv.cmpltu.sc.h rD, rs1, rs2
0 1000	1	Imm6[0|5:1]		src1	110	dest	111 1011	cv.cmpltu.sci.h rD, rs1, Imm6
0 1000	1	0	src2	src1	001	dest	111 1011	cv.cmpltu.b rD, rs1, rs2
0 1000	1	0	src2	src1	101	dest	111 1011	cv.cmpltu.sc.b rD, rs1, rs2
0 1000	1	Imm6[0|5:1]		src1	111	dest	111 1011	cv.cmpltu.sci.b rD, rs1, Imm6
0 1001	1	0	src2	src1	000	dest	111 1011	cv.cmpleu.h rD, rs1, rs2
0 1001	1	0	src2	src1	100	dest	111 1011	cv.cmpleu.sc.h rD, rs1, rs2
0 1001	1	Imm6[0|5:1]		src1	110	dest	111 1011	cv.cmpleu.sci.h rD, rs1, Imm6
0 1001	1	0	src2	src1	001	dest	111 1011	cv.cmpleu.b rD, rs1, rs2
0 1001	1	0	src2	src1	101	dest	111 1011	cv.cmpleu.sc.b rD, rs1, rs2
0 1001	1	Imm6[0|5:1]		src1	111	dest	111 1011	cv.cmpleu.sci.b rD, rs1, Imm6

SIMD Complex-number operations

SIMD Complex-number operations are extra instructions that uses the packed-SIMD extentions to represent Complex-numbers. These extentions use only the half-words mode and only operand in registers. A number C = {Re, Im} is represented as a vector of two 16-Bits signed numbers. C[0] is the real part [15:0], C[1] is the imaginary part [31:16]. Such operations are subtraction of 2 complexes with post rotation by -j, the complex and conjugate, complex multiplications and complex additions/substractions. The complex multiplications are performed in two separate instructions, one to compute the real part, and one to compute the imaginary part.

As for all the other SIMD instructions, no flags are raised and CSR register are unmodified. No carry, overflow is generated. Instructions are rounded up as the mask & 0xFFFF explicits.

SIMD Complex-number operations

Mnemonic	Description
cv.cplxmul.r{/,.div2,.div4,.div8}	rD[1] = rD[1] rD[0] = (rs1[0]*rs2[0] - rs1[1]*rs2[1]) >> {15,16,17,18} Note: Arithmetic shift right.
cv.cplxmul.i{/,.div2,.div4,.div8}	rD[1] = (rs1[0]*rs2[1] + rs1[1]*rs2[0]) >> {15,16,17,18} rD[0] = rD[0] Note: Arithmetic shift right.
cv.cplxconj	rD[1] = -rs1[1] rD[0] = rs1[0]
cv.subrotmj{/,.div2,.div4,.div8}	rD[1] = ((rs2[0] - rs1[0]) & 0xFFFF) >> {0,1,2,3} rD[0] = ((rs1[1] - rs2[1]) & 0xFFFF) >> {0,1,2,3} Note: Arithmetic shift right.
cv.add{.div2,.div4,.div8}	rD[1] = ((rs1[1] + rs2[1]) & 0xFFFF) >> {1,2,3} rD[0] = ((rs1[0] + rs2[0]) & 0xFFFF) >> {1,2,3} Note: Arithmetic shift right.
cv.sub{.div2,.div4,.div8}	rD[1] = ((rs1[1] - rs2[1]) & 0xFFFF) >> {1,2,3} rD[0] = ((rs1[0] - rs2[0]) & 0xFFFF) >> {1,2,3} Note: Arithmetic shift right.

SIMD Complex-number Encoding

SIMD Complex-number encoding

31 : 27	26	25	24 : 20	19 : 15	14 : 12	11 : 7	6 : 0
funct5	F		rs2	rs1	funct3	rD	opcode
0 1010	1	0	src2	src1	000	dest	111 1011	cv.cplxmul.r rD, rs1, rs2
0 1010	1	0	src2	src1	010	dest	111 1011	cv.cplxmul.r.div2 rD, rs1, rs2
0 1010	1	0	src2	src1	100	dest	111 1011	cv.cplxmul.r.div4 rD, rs1, rs2
0 1010	1	0	src2	src1	110	dest	111 1011	cv.cplxmul.r.div8 rD, rs1, rs2
0 1010	1	1	src2	src1	000	dest	111 1011	cv.cplxmul.i rD, rs1, rs2
0 1010	1	1	src2	src1	010	dest	111 1011	cv.cplxmul.i.div2 rD, rs1, rs2
0 1010	1	1	src2	src1	100	dest	111 1011	cv.cplxmul.i.div4 rD, rs1, rs2
0 1010	1	1	src2	src1	110	dest	111 1011	cv.cplxmul.i.div8 rD, rs1, rs2
0 1011	1	0	00000	src1	000	dest	111 1011	cv.cplxconj rD, rs1
0 1100	1	0	src2	src1	000	dest	111 1011	cv.subrotmj rD, rs1, rs2
0 1100	1	0	src2	src1	010	dest	111 1011	cv.subrotmj.div2 rD, rs1, rs2
0 1100	1	0	src2	src1	100	dest	111 1011	cv.subrotmj.div4 rD, rs1, rs2
0 1100	1	0	src2	src1	110	dest	111 1011	cv.subrotmj.div8 rD, rs1, rs2
0 1101	1	0	src2	src1	010	dest	111 1011	cv.add.div2 rD, rs1, rs2
0 1101	1	0	src2	src1	100	dest	111 1011	cv.add.div4 rD, rs1, rs2
0 1101	1	0	src2	src1	110	dest	111 1011	cv.add.div8 rD, rs1, rs2
0 1110	1	0	src2	src1	010	dest	111 1011	cv.sub.div2 rD, rs1, rs2
0 1110	1	0	src2	src1	100	dest	111 1011	cv.sub.div4 rD, rs1, rs2
0 1110	1	0	src2	src1	110	dest	111 1011	cv.sub.div8 rD, rs1, rs2