d0p1/tcc-stupidos
1
1
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

arm-asm: Support bigger immediates for data processing instructions

Browse source
This commit is contained in:
Danny Milosavljevic 2021-01-03 02:28:19 +01:00
parent 14b7973ab5
commit d66c155239
No known key found for this signature in database
GPG key ID: E71A35542C30BAA5
1 changed files with 40 additions and 17 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

57
arm-asm.c
View file

@ -550,6 +550,8 @@ static void asm_data_processing_opcode(TCCState *s1, int token)
return;
} else {
uint32_t opcode = 0;
uint32_t immediate_value;
uint8_t half_immediate_rotation;
if (nb_shift && shift.type == OP_REG32) {
if ((ops[0].type == OP_REG32 && ops[0].reg == 15) ||
(ops[1].type == OP_REG32 && ops[1].reg == 15)) {
@ -583,11 +585,25 @@ static void asm_data_processing_opcode(TCCState *s1, int token)
operands |= ops[2].reg;
break;
case OP_IM8:
case OP_IM32:
operands |= ENCODE_IMMEDIATE_FLAG;
operands |= ops[2].e.v;
break;
immediate_value = ops[2].e.v;
for (half_immediate_rotation = 0; half_immediate_rotation < 16; ++half_immediate_rotation) {
if (immediate_value >= 0x00 && immediate_value < 0x100)
break;
// rotate left by two
immediate_value = ((immediate_value & 0x3FFFFFFF) << 2) | ((immediate_value & 0xC0000000) >> 30);
}
if (half_immediate_rotation >= 16) {
/* fallthrough */
} else {
operands |= immediate_value;
operands |= half_immediate_rotation << 8;
break;
}
case OP_IM8N: // immediate negative value
operands |= ENCODE_IMMEDIATE_FLAG;
immediate_value = ops[2].e.v;
/* Instruction swapping:
0001 = EOR - Rd:= Op1 EOR Op2 -> difficult
0011 = RSB - Rd:= Op2 - Op1 -> difficult
@ -597,54 +613,61 @@ static void asm_data_processing_opcode(TCCState *s1, int token)
1100 = ORR - Rd:= Op1 OR Op2 -> difficult
*/
switch (opcode_nos) {
#if 0
case 0x0: // AND - Rd:= Op1 AND Op2
opcode = 0xe << 21; // BIC
operands |= (ops[2].e.v ^ 0xFF) & 0xFF;
immediate_value = ~immediate_value;
break;
case 0x2: // SUB - Rd:= Op1 - Op2
opcode = 0x4 << 21; // ADD
operands |= (-ops[2].e.v) & 0xFF;
immediate_value = -immediate_value;
break;
case 0x4: // ADD - Rd:= Op1 + Op2
opcode = 0x2 << 21; // SUB
operands |= (-ops[2].e.v) & 0xFF;
immediate_value = -immediate_value;
break;
case 0x5: // ADC - Rd:= Op1 + Op2 + C
opcode = 0x6 << 21; // SBC
operands |= (ops[2].e.v ^ 0xFF) & 0xFF;
immediate_value = ~immediate_value;
break;
case 0x6: // SBC - Rd:= Op1 - Op2 + C
opcode = 0x5 << 21; // ADC
operands |= (ops[2].e.v ^ 0xFF) & 0xFF;
immediate_value = ~immediate_value;
break;
#endif
case 0xa: // CMP - CC on: Op1 - Op2
opcode = 0xb << 21; // CMN
operands |= (-ops[2].e.v) & 0xFF;
immediate_value = -immediate_value;
break;
case 0xb: // CMN - CC on: Op1 + Op2
opcode = 0xa << 21; // CMP
operands |= (-ops[2].e.v) & 0xFF;
immediate_value = -immediate_value;
break;
// moveq r1, r3: 0x01a01003; mov Rd, Op2
case 0xd: // MOV - Rd:= Op2
opcode = 0xf << 21; // MVN
operands |= (ops[2].e.v ^ 0xFF) & 0xFF;
immediate_value = ~immediate_value;
break;
#if 0
case 0xe: // BIC - Rd:= Op1 AND NOT Op2
opcode = 0x0 << 21; // AND
operands |= (ops[2].e.v ^ 0xFF) & 0xFF;
immediate_value = ~immediate_value;
break;
#endif
case 0xf: // MVN - Rd:= NOT Op2
opcode = 0xd << 21; // MOV
operands |= (ops[2].e.v ^ 0xFF) & 0xFF;
immediate_value = ~immediate_value;
break;
default:
tcc_error("cannot use '%s' with a negative immediate value", get_tok_str(token, NULL));
}
for (half_immediate_rotation = 0; half_immediate_rotation < 16; ++half_immediate_rotation) {
if (immediate_value >= 0x00 && immediate_value < 0x100)
break;
// rotate left by two
immediate_value = ((immediate_value & 0x3FFFFFFF) << 2) | ((immediate_value & 0xC0000000) >> 30);
}
if (half_immediate_rotation >= 16) {
tcc_error("immediate value 0x%X cannot be encoded into ARM immediate", (unsigned) immediate_value);
return;
}
operands |= immediate_value;
operands |= half_immediate_rotation << 8;
break;
default:
expect("(second source operand) register or immediate value");