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riscv64-asm.c: added asm_emit_j (J-type), changed jal to J-type

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additionally added a comment about B-type instruction format
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noneofyourbusiness 2023-11-26 11:59:02 +01:00
parent fb164e0ab4
commit 70328621f1
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1 changed files with 45 additions and 1 deletions
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46
riscv64-asm.c
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@ -112,6 +112,7 @@ typedef struct Operand {
} Operand;
static void asm_emit_i(int token, uint32_t opcode, const Operand* rd, const Operand* rs1, const Operand* rs2);
static void asm_emit_j(int token, uint32_t opcode, const Operand* rd, const Operand* rs2);
/* Parse a text containing operand and store the result in OP */
static void parse_operand(TCCState *s1, Operand *op)
@ -218,7 +219,7 @@ static void asm_binary_opcode(TCCState* s1, int token)
asm_emit_u(token, (0x05 << 2) | 3, &ops[0], &ops[1]);
return;
case TOK_ASM_jal:
asm_emit_u(token, 0x6f, ops, ops + 1);
asm_emit_j(token, 0x6f, ops, ops + 1);
return;
default:
expect("binary instruction");
@ -275,6 +276,40 @@ static void asm_emit_i(int token, uint32_t opcode, const Operand* rd, const Oper
gen_le32(opcode | ENCODE_RD(rd->reg) | ENCODE_RS1(rs1->reg) | (rs2->e.v << 20));
}
static void asm_emit_j(int token, uint32_t opcode, const Operand* rd, const Operand* rs2)
{
uint64_t imm;
if (rd->type != OP_REG) {
tcc_error("'%s': Expected destination operand that is a register", get_tok_str(token, NULL));
return;
}
if (rs2->type != OP_IM12S && rs2->type != OP_IM32) {
tcc_error("'%s': Expected second source operand that is an immediate value", get_tok_str(token, NULL));
return;
}
imm = rs2->e.v;
if (imm >= 0x100000) {
tcc_error("'%s': Expected second source operand that is an immediate value between 0 and 0xfffff", get_tok_str(token, NULL));
return;
}
if (imm & 1) {
tcc_error("'%s': Expected second source operand that is an even immediate value", get_tok_str(token, NULL));
return;
}
/* J-type instruction:
31 imm[20]
30...21 imm[10:1]
20 imm[11]
19...12 imm[19:12]
11...7 rd
6...0 opcode */
gen_le32(opcode | ENCODE_RD(rd->reg) | (((imm >> 20) & 1) << 31) | (((imm >> 1) & 0x3ff) << 21) | (((imm >> 11) & 1) << 20) | (((imm >> 12) & 0xff) << 12));
}
static void asm_shift_opcode(TCCState *s1, int token)
{
Operand ops[3];
@ -571,6 +606,15 @@ static void asm_branch_opcode(TCCState* s1, int token)
default:
expect("known branch instruction");
}
/* B-type instruction:
31 imm[12]
30...25 imm[10:5]
24...20 rs2
19...15 rs1
14...12 funct3
8...11 imm[4:1]
7 imm[11]
6...0 opcode */
asm_emit_opcode(opcode | ENCODE_RS1(ops[0].reg) | ENCODE_RS2(ops[1].reg) | (((offset >> 1) & 0xF) << 8) | (((offset >> 5) & 0x1f) << 25) | (((offset >> 11) & 1) << 7) | (((offset >> 12) & 1) << 31));
}