ed255 / RISC_V_RV64I_cheatsheet

I write a C-style pseudo codes to describe what does every single RV64I instruction do. If you spot something wrong, change it plz

RISC-V RV64I cheatsheet

I write C style pseudo codes to explain what does every single RV64I instruction do(not include privileged instructions). rm register for medium operations.

ALU:

1. arithmatic

add rd, rs1, rs2

  rd = rs1 + rs2;
  pc = pc + 4;

addw rd, rs1, rs2

  rd = rs1 + rs2;
  rd = extend_signed_32bit(rd);
  pc = pc + 4;

addi rd, rs1, IMMEDIATE

  rd = extend_signed_12bit(IMMEDIATE);
  rd = rs1 + rd;
  pc = pc + 4;

addiw rd, rs1, IMMEDIATE

  rd = extend_signed_12bit(IMMEDIATE);
  rd = rs1 + rd;
  rd = extend_signed_32bit(rd);
  pc = pc + 4;

auipc rd, IMMEDIATE_UPPER

  rd = IMMEDIATE_UPPER;
  rd = rd << 20;
  rd = extend_signed_32bit(rd);
  rd = pc + rd;
  pc = pc + 4;

sub rd, rs1, rs2

  rd = rs1 - rs2;
  pc = pc + 4;

subw rd, rs1, rs2

  rd = rs1 - rs2;
  rd = extend_signed_32bit(rd);
  pc = pc + 4;

2. logical shift

srl rd, rs1, rs2

  rd = rs2 & 63;
  rd = (uint64_t)rs1 >> rd;
  pc = oc + 4;

srlw rd, rs1, rs2

  rd = rs2 & 31;
  rd = (uint64_t)rs1 >> rd;
  rd = extend_signed_32bit(rd);
  pc = pc + 4;

srli rd, rs1, IMMEDIATE_SHIFTAMOUNT63

  rd = extend_unsigned_6bit(IMMEDIATE_SHIFTAMOUNT63);
  rd = (uint64_t)rs1 >> rd;
  pc = pc + 4;

srliw rd, rs1, IMMEDIATE_SHIFTAMOUNT31

  rd = extend_unsigned_5bit(IMMEDIATE_SHIFTAMOUNT31);
  rd = (uint64_t)rs1 >> rd;
  rd = extend_signed_32bit(rd);
  pc = pc + 4;

sll rd, rs1, rs2

  rd = rs2 & 63;
  rd = rs1 << rd;
  pc = oc + 4;

sllw rd, rs1, rs2

  rd = rs2 & 31;
  rd = rs1 << rd;
  rd = extend_signed_32bit(rd);
  pc = pc + 4;

slli rd, rs1, IMMEDIATE_SHIFTAMOUNT63

  rd = extend_unsigned_6bit(IMMEDIATE_SHIFTAMOUNT63);
  rd = rs1 << rd;
  pc = pc + 4;

slliw rd, rs1, IMMEDIATE_SHIFTAMOUNT31

  rd = extend_unsigned_5bit(IMMEDIATE_SHIFTAMOUNT31);
  rd = rs1 << rd;
  rd = extend_signed_32bit(rd);
  pc = pc + 4;

3. arithmatic shift

sra rd, rs1, rs2

  rd = rs2 & 63;
  rd = rs1 >> rd;
  pc = pc + 4;

sraw rd, rs1, rs2

  rd = rs2 & 31;
  rd = rs1 >> rd;
  rd = extend_signed_32bit(rd);
  pc = pc + 4;

srai rd, rs1, IMMEDIATE_SHIFTAMOUNT63

  rd = extend_unsigned_6bit(IMMEDIATE_SHIFTAMOUNT63);
  rd = rs1 >> rd;
  pc = pc + 4;

sraiw rd, rs1, IMMEDIATE_SHIFTAMOUNT31

  rd = extend_unsigned_5bit(IMMEDIATE_SHIFTAMOUNT31);
  rd = rs1 >> rd;
  rd = extend_signed_32bit(rd);
  pc = pc + 4;

4. boolean bitwise

and rd, rs1, rs2

  rd = rs1 & rs2;
  pc = pc + 4;

andi rd, rs1, IMMEDIATE

  rd = extend_signed_12bit(IMMEDIATE);
  rd = rs1 & rd;
  pc = pc + 4;

or rd, rs1, rs2

  rd = rs1 | rs2;
  pc = pc + 4;

ori rd, rs1, IMMEDIATE

  rd = extend_signed_12bit(IMMEDIATE);
  rd = rs1 | rd;
  pc = pc + 4;

xor rd, rs1, rs2

  rd = rs1 ^ rs2;
  pc = pc + 4;

ori rd, rs1, IMMEDIATE

  rd = extend_signed_12bit(IMMEDIATE);
  rd = rs1 ^ rd;
  pc = pc + 4;

5. comparison

slt rd, rs1, rs2

  rd = rs1 < rs2;
  pc = pc + 4;

sltu rd, rs1, rs2

  rd = (uint64_t)rs1 < (uint64_t)rs2;
  pc = pc + 4;

slti rd, rs1, IMMEDIATE

  rd = extend_signed_12bit(IMMEDIATE);
  rd = rs1 < rd;
  pc = pc + 4;

sltiu rd, rs1, IMMEDIATE

  rd = extend_signed_12bit(IMMEDIATE);
  rd = (uint64_t)rs1 < (uint64_t)rd;
  pc = pc + 4;

transfer control:

1. conditional

beq rs1, rs2, IMMEDIATE_BRANCH

  rm1 = rs1 == rs2;
  rm2 = IMMEDIATE_BRANCH;
  rm2 = rm2 << 1;
  rm2 = extend_signed_13bit(rm2);
  rm2 = rm2 - 4;
  rm2 = rm2 * rm1;
  pc = pc + 4;
  pc = pc + rm2;

bne rs1, rs2, IMMEDIATE_BRANCH

  rm1 = rs1 != rs2;
  rm2 = IMMEDIATE_BRANCH;
  rm2 = rm2 << 1;
  rm2 = extend_signed_13bit(rm2);
  rm2 = rm2 - 4;
  rm2 = rm2 * rm1;
  pc = pc + 4;
  pc = pc + rm2;

blt rs1, rs2, IMMEDIATE_BRANCH

  rm1 = rs1 < rs2;
  rm2 = IMMEDIATE_BRANCH;
  rm2 = rm2 << 1;
  rm2 = extend_signed_13bit(rm2);
  rm2 = rm2 - 4;
  rm2 = rm2 * rm1;
  pc = pc + 4;
  pc = pc + rm2;

bltu rs1, rs2, IMMEDIATE_BRANCH

  rm1 = (uint64_t)rs1 < (uint64_t)rs2;
  rm2 = IMMEDIATE_BRANCH;
  rm2 = rm2 << 1;
  rm2 = extend_signed_13bit(rm2);
  rm2 = rm2 - 4;
  rm2 = rm2 * rm1;
  pc = pc + 4;
  pc = pc + rm2;

bge rs1, rs2, IMMEDIATE_BRANCH

  rm1 = rs1 >= rs2;
  rm2 = IMMEDIATE_BRANCH;
  rm2 = rm2 << 1;
  rm2 = extend_signed_13bit(rm2);
  rm2 = rm2 - 4;
  rm2 = rm2 * rm1;
  pc = pc + 4;
  pc = pc + rm2;

bgeu rs1, rs2, IMMEDIATE_BRANCH

  rm1 = (uint64_t)rs1 >= (uint64_t)rs2;
  rm2 = IMMEDIATE_BRANCH;
  rm2 = rm2 << 1;
  rm2 = extend_signed_13bit(rm2);
  rm2 = rm2 - 4;
  rm2 = rm2 * rm1;
  pc = pc + 4;
  pc = pc + rm2;

2. unconditional

jal rd, IMMEDIATE_JUMP

  rd = pc + 4;
  rm1 = IMMEDIATE_JUMP;
  rm1 = rm1 << 1;
  rm1 = extend_signed_21bit(rm1);
  pc = pc + rm1;

jalr rd, rs1, IMMEDIATE

  rd = pc + 4;
  rm1 = extend_signed_12bit(IMMEDIATE);
  pc = rs1 + rm1;
  pc = pc & -2;

data transmission:

1. load

lb rd, IMMEDIATE(rs1)

  rd = extend_signed_12bit(IMMEDIATE);
  rs1 = rs1 + rd;
  rd = *(int8_t*)rs1;

lbu rd, IMMEDIATE(rs1)

  rd = extend_signed_12bit(IMMEDIATE);
  rs1 = rs1 + rd;
  rd = *(uint8_t*)rs1;

lh rd, IMMEDIATE(rs1)

  rd = extend_signed_12bit(IMMEDIATE);
  rs1 = rs1 + rd;
  rd = *(int16_t*)rs1;

lhu rd, IMMEDIATE(rs1)

  rd = extend_signed_12bit(IMMEDIATE);
  rs1 = rs1 + rd;
  rd = *(uint16_t*)rs1;

lw rd, IMMEDIATE(rs1)

  rd = extend_signed_12bit(IMMEDIATE);
  rs1 = rs1 + rd;
  rd = *(int32_t*)rs1;

lwu rd, IMMEDIATE(rs1)

  rd = extend_signed_12bit(IMMEDIATE);
  rs1 = rs1 + rd;
  rd = *(uint32_t*)rs1;

ld rd, IMMEDIATE(rs1)

  rd = extend_signed_12bit(IMMEDIATE);
  rs1 = rs1 + rd;
  rd = *(int64_t*)rs1;

lui rd, IMMEDIATE_UPPER

  rd = IMMEDIATE_UPPER;
  rd = rd << 20;
  rd = extend_signed_32bit(rd);
  pc = pc + 4;

2. store

sb rs2, IMMEDIATE_STORE(rs1)

  rm1 = extend_signed_12bit(IMMEDIATE_STORE);
  rs1 = rs1 + rm1;
  *(int8_t*)rs1 = rs2;

sh rs2, IMMEDIATE_STORE(rs1)

  rm1 = extend_signed_12bit(IMMEDIATE_STORE);
  rs1 = rs1 + rm1;
  *(int16_t*)rs1 = rs2;

sw rs2, IMMEDIATE_STORE(rs1)

  rm1 = extend_signed_12bit(IMMEDIATE_STORE);
  rs1 = rs1 + rm1;
  *(int32_t*)rs1 = rs2;

sd rs2, IMMEDIATE_STORE(rs1)

  rm1 = extend_signed_12bit(IMMEDIATE_STORE);
  rs1 = rs1 + rm1;
  *(int64_t*)rs1 = rs2;