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arm-asm: Support shift of 0 in asm_shift_opcode

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Danny Milosavljevic 2021-01-03 06:04:10 +01:00
parent 9539f51369
commit a7205f738b
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GPG key ID: E71A35542C30BAA5
1 changed files with 21 additions and 35 deletions
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56
arm-asm.c
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@ -433,26 +433,6 @@ static void asm_block_data_transfer_opcode(TCCState *s1, int token)
} }
} }
static uint32_t asm_encode_rotation(Operand* rotation)
{
uint64_t amount;
switch (rotation->type) {
case OP_REG32:
tcc_error("cannot rotate immediate value by register");
return 0;
case OP_IM8:
amount = rotation->e.v;
if (amount >= 0 && amount < 32 && (amount & 1) == 0)
return (amount >> 1) << 8;
else
tcc_error("rotating is only possible by a multiple of 2");
break;
default:
tcc_error("unknown rotation amount");
return 0;
}
}
static uint32_t asm_encode_shift(Operand* shift) static uint32_t asm_encode_shift(Operand* shift)
{ {
uint64_t amount; uint64_t amount;
@ -690,6 +670,7 @@ static void asm_shift_opcode(TCCState *s1, int token)
{ {
Operand ops[3]; Operand ops[3];
int nb_ops; int nb_ops;
int definitely_neutral = 0;
uint32_t opcode = 0xd << 21; // MOV uint32_t opcode = 0xd << 21; // MOV
uint32_t operands = 0; uint32_t operands = 0;
@ -736,6 +717,15 @@ static void asm_shift_opcode(TCCState *s1, int token)
return; return;
} }
switch (ARM_INSTRUCTION_GROUP(token)) {
case TOK_ASM_lslseq:
case TOK_ASM_lsrseq:
case TOK_ASM_asrseq:
case TOK_ASM_rorseq:
opcode |= ENCODE_SET_CONDITION_CODES;
break;
}
switch (ops[1].type) { switch (ops[1].type) {
case OP_REG32: case OP_REG32:
operands |= ops[1].reg; operands |= ops[1].reg;
@ -746,40 +736,36 @@ static void asm_shift_opcode(TCCState *s1, int token)
break; break;
} }
if (ops[2].type == OP_REG32) { switch (ops[2].type) {
case OP_REG32:
if ((ops[0].type == OP_REG32 && ops[0].reg == 15) || if ((ops[0].type == OP_REG32 && ops[0].reg == 15) ||
(ops[1].type == OP_REG32 && ops[1].reg == 15)) { (ops[1].type == OP_REG32 && ops[1].reg == 15)) {
tcc_error("Using the 'pc' register in data processing instructions that have a register-controlled shift is not implemented by ARM"); tcc_error("Using the 'pc' register in data processing instructions that have a register-controlled shift is not implemented by ARM");
} }
operands |= asm_encode_shift(&ops[2]);
break;
case OP_IM8:
if (ops[2].e.v)
operands |= asm_encode_shift(&ops[2]);
else
definitely_neutral = 1;
break;
} }
if (operands & ENCODE_IMMEDIATE_FLAG) if (!definitely_neutral) switch (ARM_INSTRUCTION_GROUP(token)) {
operands |= asm_encode_rotation(&ops[2]);
else
operands |= asm_encode_shift(&ops[2]);
switch (ARM_INSTRUCTION_GROUP(token)) {
case TOK_ASM_lslseq: case TOK_ASM_lslseq:
opcode |= ENCODE_SET_CONDITION_CODES;
/* fallthrough */
case TOK_ASM_lsleq: case TOK_ASM_lsleq:
operands |= ENCODE_BARREL_SHIFTER_MODE_LSL; operands |= ENCODE_BARREL_SHIFTER_MODE_LSL;
break; break;
case TOK_ASM_lsrseq: case TOK_ASM_lsrseq:
opcode |= ENCODE_SET_CONDITION_CODES;
/* fallthrough */
case TOK_ASM_lsreq: case TOK_ASM_lsreq:
operands |= ENCODE_BARREL_SHIFTER_MODE_LSR; operands |= ENCODE_BARREL_SHIFTER_MODE_LSR;
break; break;
case TOK_ASM_asrseq: case TOK_ASM_asrseq:
opcode |= ENCODE_SET_CONDITION_CODES;
/* fallthrough */
case TOK_ASM_asreq: case TOK_ASM_asreq:
operands |= ENCODE_BARREL_SHIFTER_MODE_ASR; operands |= ENCODE_BARREL_SHIFTER_MODE_ASR;
break; break;
case TOK_ASM_rorseq: case TOK_ASM_rorseq:
opcode |= ENCODE_SET_CONDITION_CODES;
/* fallthrough */
case TOK_ASM_roreq: case TOK_ASM_roreq:
operands |= ENCODE_BARREL_SHIFTER_MODE_ROR; operands |= ENCODE_BARREL_SHIFTER_MODE_ROR;
break; break;