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riscv: asm: implement j offset

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This commit is contained in:
Ekaitz Zarraga 2024-04-25 15:00:12 +02:00
parent 159776304f
commit 8baadb3b55
1 changed files with 33 additions and 19 deletions
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52
riscv64-asm.c
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@ -244,6 +244,25 @@ static void parse_branch_offset_operand(TCCState *s1, Operand *op){
}
}
static void parse_jump_offset_operand(TCCState *s1, Operand *op){
ExprValue e = {0};
asm_expr(s1, &e);
op->type = OP_IM32;
op->e = e;
/* compare against unsigned 12-bit maximum */
if (!op->e.sym) {
if ((int) op->e.v >= -0x1000 && (int) op->e.v < 0x1000)
op->type = OP_IM12S;
} else if (op->e.sym->type.t & (VT_EXTERN | VT_STATIC)) {
greloca(cur_text_section, op->e.sym, ind, R_RISCV_JAL, 0);
op->type = OP_IM12S;
op->e.v = 0;
} else {
expect("operand");
}
}
static void parse_operands(TCCState *s1, Operand* ops, int count){
int i;
for (i = 0; i < count; i++) {
@ -296,27 +315,19 @@ static void parse_mem_access_operands(TCCState *s1, Operand* ops){
/* This is special: First operand is optional */
static void asm_jal_opcode(TCCState *s1, int token){
static const Operand ra = {.type = OP_REG, .reg = 1};
static const Operand zero = {.type = OP_REG};
Operand ops[2];
parse_operand(s1, &ops[0]);
if ( ops[0].type != OP_REG ) {
/* no more operands, it's the pseudoinstruction:
* jal offset
* Expand to:
* jal ra, offset
*/
ops[1] = ops[0];
ops[0] = ra;
goto emit;
}
if ( tok == ',')
next();
else
expect("','");
parse_operand(s1, &ops[1]);
emit:
if (ops[1].e.sym && ops[1].e.sym->type.t & (VT_EXTERN | VT_STATIC)){
greloca(cur_text_section, ops[1].e.sym, ind, R_RISCV_JAL, 0);
if (token == TOK_ASM_j ){
ops[0] = zero; // j offset
} else if (asm_parse_regvar(tok) == -1) {
ops[0] = ra; // jal offset
} else {
// jal reg, offset
parse_operand(s1, &ops[0]);
if ( tok == ',') next(); else expect("','");
}
parse_jump_offset_operand(s1, &ops[1]);
asm_emit_j(token, 0x6f, &ops[0], &ops[1]);
}
@ -1309,6 +1320,9 @@ ST_FUNC void asm_opcode(TCCState *s1, int token)
case TOK_ASM_jalr:
asm_jalr_opcode(s1, token); /* it can be a pseudo instruction too*/
break;
case TOK_ASM_j:
asm_jal_opcode(s1, token); /* jal zero, offset*/
return;
case TOK_ASM_jal:
asm_jal_opcode(s1, token); /* it can be a pseudo instruction too*/
break;