initial version of regalloc

This commit is contained in:
Yaossg 2024-11-21 20:23:11 +08:00
parent b8108acb2e
commit 40eb2ce96f
2 changed files with 392 additions and 196 deletions

584
boot.c
View File

@ -429,8 +429,8 @@ int parse_type() {
int epilog_label;
int local_table[4096]; // id -> local id
int next_local_id = 2;
int max_local_id = 2;
int next_local_id = 12;
int max_local_id = 12;
const int MARKER_TEMP = 0;
const int MARKER_SCALAR = 1;
@ -441,47 +441,137 @@ int local_marker[4096];
int global_marker[4096];
int local_type[4096];
int global_type[4096];
int reg_type[4096];
int next_reg_id = 18;
int max_reg_id = 18;
int indirection[4096];
int overflow[4096];
const int REG_ZERO = 0;
const int REG_RA = 1;
const int REG_SP = 2;
const int REG_GP = 3;
const int REG_TP = 4;
const int REG_T0 = 5;
const int REG_T1 = 6;
const int REG_T2 = 7;
const int REG_FP = 8;
const int REG_S1 = 9;
const int REG_A0 = 10;
const int REG_A1 = 11;
const int REG_A2 = 12;
const int REG_A3 = 13;
const int REG_A4 = 14;
const int REG_A5 = 15;
const int REG_A6 = 16;
const int REG_A7 = 17;
const int REG_S2 = 18;
const int REG_S3 = 19;
const int REG_S4 = 20;
const int REG_S5 = 21;
const int REG_S6 = 22;
const int REG_S7 = 23;
const int REG_S8 = 24;
const int REG_S9 = 25;
const int REG_S10 = 26;
const int REG_S11 = 27;
const int REG_T3 = 28;
const int REG_T4 = 29;
const int REG_T5 = 30;
const int REG_T6 = 31;
void reset_reg() {
next_reg_id = REG_S2;
for (int i = 0; i < 4096; ++i) {
reg_type[i] = TYPE_VOID;
indirection[i] = 0;
overflow[i] = 0;
}
}
const char* reg_name(int reg) {
if (reg == 0) return "zero";
if (reg == 1) return "ra";
if (reg == 2) return "sp";
if (reg == 3) return "gp";
if (reg == 4) return "tp";
if (reg == 5) return "t0";
if (reg == 6) return "t1";
if (reg == 7) return "t2";
if (reg == 8) return "fp";
// reserved begin
if (reg == 9) return "s1";
if (reg == 10) return "a0";
if (reg == 11) return "a1";
if (reg == 12) return "a2";
if (reg == 13) return "a3";
if (reg == 14) return "a4";
if (reg == 15) return "a5";
if (reg == 16) return "a6";
if (reg == 17) return "a7";
// allocation begin
if (reg == 18) return "s2";
if (reg == 19) return "s3";
if (reg == 20) return "s4";
if (reg == 21) return "s5";
if (reg == 22) return "s6";
if (reg == 23) return "s7";
if (reg == 24) return "s8";
if (reg == 25) return "s9";
if (reg == 26) return "s10";
if (reg == 27) return "s11";
// overflow begin
if (reg == 28) return "t3";
if (reg == 29) return "t4";
if (reg == 30) return "t5";
if (reg == 31) return "t6";
return 0;
}
int is_overflow(int reg) {
return reg > REG_S11;
}
void reset_local() {
next_local_id = 2;
max_local_id = 2;
next_local_id = 12;
max_local_id = 12;
for (int i = 0; i < 4096; ++i) {
local_table[i] = 0;
local_marker[i] = MARKER_TEMP;
local_type[i] = TYPE_VOID;
indirection[i] = 0;
}
reset_reg();
}
void reset_temp() {
while (next_local_id > 2 && local_marker[next_local_id - 1] == MARKER_TEMP) {
while (next_local_id > 12 && local_marker[next_local_id - 1] == MARKER_TEMP) {
--next_local_id;
}
reset_reg();
}
int next_reg(int type) {
int reg = next_local_id++;
local_type[reg] = type;
indirection[reg] = 0;
int next_local_slot(int type) {
int slot = next_local_id++;
local_type[slot] = type;
if (next_local_id > max_local_id) {
max_local_id = next_local_id;
}
return reg;
return slot;
}
int declare_local(int id, int type) {
if (local_table[id] != 0) return local_table[id];
int reg = next_reg(type);
local_marker[reg] = MARKER_SCALAR;
return local_table[id] = reg;
int slot = next_local_slot(type);
local_marker[slot] = MARKER_SCALAR;
return local_table[id] = slot;
}
int declare_local_array(int id, int type, int size) {
if (local_table[id] != 0) return local_table[id];
int reg;
for (int i = 0; i < size; ++i) local_marker[reg = next_reg(type)] = MARKER_ARRAY;
return local_table[id] = reg;
int slot;
for (int i = 0; i < size; ++i) local_marker[slot = next_local_slot(type)] = MARKER_ARRAY;
return local_table[id] = slot;
}
void declare_global(int id, int marker, int type) {
@ -489,6 +579,23 @@ void declare_global(int id, int marker, int type) {
global_type[id] = type;
}
int next_reg(int type) {
int reg = next_reg_id++;
if (is_overflow(reg)) {
int slot = next_local_slot(type);
local_marker[slot] = MARKER_TEMP;
overflow[reg] = slot;
}
reg_type[reg] = type;
if (next_reg_id > max_reg_id) {
max_reg_id = next_reg_id;
}
return reg;
}
// prolog & epilog helpers
int check_itype_immediate(int value) {
return value >= -2048 && value <= 2047;
}
@ -522,74 +629,176 @@ void asm_addi(const char* rd, const char* rs, int imm) {
}
}
void load_address(int rd, int id) {
if (id == -1) {
eprintf("void cannot be arithmetically operated\n");
exit(1);
}
int offset = -id * 8 - 8;
if (indirection[id]) {
if (check_itype_immediate(offset)) {
printf(" ld t%d, %d(fp) # indirection\n", rd, offset);
} else {
printf(" li t%d, %d\n", rd, offset);
printf(" add t%d, fp, t%d\n", rd, rd);
printf(" ld t%d, 0(t%d) # indirection\n", rd, rd);
}
// assembly helpers
// address loaders
// rd must be one of 0, 1, 2
void load_local_address(int rd, int slot_id) {
// TODO use sp instead
int offset = -slot_id * 8 - 8;
const char* rd_name = reg_name(rd);
if (check_itype_immediate(offset)) {
printf(" addi %s, fp, %d\n", rd_name, offset);
} else {
if (check_itype_immediate(offset)) {
printf(" addi t%d, fp, %d\n", rd, offset);
} else {
printf(" li t%d, %d\n", rd, offset);
printf(" add t%d, fp, t%d\n", rd, rd);
printf(" li %s, %d\n", rd_name, offset);
printf(" add %s, fp, %s\n", rd_name, rd_name);
}
}
const char* load_op(int reg) {
int type = reg_type[reg];
if (type & TYPE_PTR_MASK) {
return "ld";
} else if (type == TYPE_CHAR) {
return "lb";
} else { // int
return "lw";
}
}
const char* store_op_of_type(int type) {
if (type & TYPE_PTR_MASK) {
return "sd";
} else if (type == TYPE_CHAR) {
return "sb";
} else { // int
return "sw";
}
}
const char* store_op(int reg) {
return store_op_of_type(reg_type[reg]);
}
// load a non-trivial register into t0, t1 or t2
// rd must be one of t0, t1, t2
void load(int rd, int reg) {
const char* op = load_op(reg);
const char* rd_name = reg_name(rd);
if (is_overflow(reg)) {
load_local_address(rd, overflow[reg]);
if (indirection[reg]) {
printf(" ld %s, 0(%s)\n", rd_name, rd_name);
}
reg = rd;
}
printf(" %s %s, 0(%s) # load non-trivial register\n", op, rd_name, reg_name(reg));
}
// store t0 into a non-trivial register
void store_t0(int reg) {
const char* op = store_op(reg);
if (is_overflow(reg)) {
load_local_address(REG_T2, overflow[reg]);
if (indirection[reg]) {
printf(" ld t2, 0(t2)\n");
}
reg = REG_T2;
}
printf(" %s t0, 0(%s) # store non-trivial register\n", op, reg_name(reg));
}
int is_nontrivial(int reg) {
return is_overflow(reg) || indirection[reg];
}
void _asm_r(const char* op, int rd, int rs1) {
const char* rd_name = reg_name(rd);
const char* rs1_name = reg_name(rs1);
if (is_nontrivial(rd)) rd_name = "t0";
if (is_nontrivial(rs1)) {
rs1_name = "t0";
load(REG_T0, rs1);
}
printf(" %s %s, %s\n", op, rd_name, rs1_name);
if (is_nontrivial(rd)) {
store_t0(rd);
}
}
void load(int rd, int id) {
load_address(rd, id);
int type = local_type[id];
const char* op = "lw"; // int
if (type == TYPE_CHAR) {
op = "lb";
} else if (type & TYPE_PTR_MASK) {
op = "ld";
void _asm_rr(const char* op, int rd, int rs1, int rs2) {
const char* rd_name = reg_name(rd);
const char* rs1_name = reg_name(rs1);
const char* rs2_name = reg_name(rs2);
if (is_nontrivial(rd)) rd_name = "t0";
if (is_nontrivial(rs1)) {
rs1_name = "t0";
load(REG_T0, rs1);
}
if (is_nontrivial(rs2)) {
rs2_name = "t1";
load(REG_T1, rs2);
}
printf(" %s %s, %s, %s\n", op, rd_name, rs1_name, rs2_name);
if (is_nontrivial(rd)) {
store_t0(rd);
}
printf(" %s t%d, 0(t%d) # id: type %d\n", op, rd, rd, type);
}
void store_t0(int id) {
load_address(1, id);
int type = local_type[id];
const char* op = "sw"; // int
if (type == TYPE_CHAR) {
op = "sb";
} else if (type & TYPE_PTR_MASK) {
op = "sd";
void _asm_ri(const char* op, int rd, int rs1, int imm) {
const char* rd_name = reg_name(rd);
const char* rs1_name = reg_name(rs1);
if (is_nontrivial(rd)) rd_name = "t0";
if (is_nontrivial(rs1)) {
rs1_name = "t0";
load(REG_T0, rs1);
}
printf(" %s t0, 0(t1) # id: type %d\n", op, type);
printf(" %s %s, %s, %d\n", op, rd_name, rs1_name, imm);
if (is_nontrivial(rd)) {
store_t0(rd);
}
}
void _asm_branch(const char* op, int rs1, int label) {
const char* rs1_name = reg_name(rs1);
if (is_nontrivial(rs1)) {
rs1_name = "t0";
load(REG_T0, rs1);
}
printf(" %s %s, L%d\n", op, rs1_name, label);
}
int asm_r(int type, const char* op, int rs1) {
int rd = next_reg(type);
_asm_r(op, rd, rs1);
return rd;
}
int asm_rr(int type, const char* op, int rs1, int rs2) {
int rd = next_reg(type);
_asm_rr(op, rd, rs1, rs2);
return rd;
}
void asm_mv(int rd, int rs1) {
_asm_r("mv", rd, rs1);
}
int materialize_t0(int type) {
int reg = next_reg(type);
store_t0(reg);
return reg;
int rd = next_reg(type);
asm_mv(rd, REG_T0);
return rd;
}
int dereference(int reg) {
local_type[reg] = local_type[reg] & ~TYPE_PTR_MASK;
indirection[reg] = 1;
return reg;
int materialize_address(int type, int marker) {
if (marker == MARKER_ARRAY) {
type = type | TYPE_PTR_MASK;
}
int rd = materialize_t0(TYPE_VOID_PTR);
reg_type[rd] = type;
indirection[rd] = marker == MARKER_SCALAR;
return rd;
}
int lookup_from_slot(int slot) {
load_local_address(REG_T0, slot);
return materialize_address(local_type[slot], local_marker[slot]);
}
int lookup(int id) {
int local = local_table[id];
if (local) {
if (local_marker[local] == MARKER_ARRAY) {
load_address(0, local);
return materialize_t0(local_type[local] | TYPE_PTR_MASK);
}
return local;
int slot = local_table[id];
if (slot) {
return lookup_from_slot(slot);
}
const char* name = id_table + id_lut[id];
if (global_marker[id]) {
@ -598,11 +807,7 @@ int lookup(int id) {
exit(1);
}
printf(" la t0, %s # id: %d\n", name, id);
int reg = materialize_t0(global_type[id] | TYPE_PTR_MASK);
if (global_marker[id] == MARKER_SCALAR) {
reg = dereference(reg);
}
return reg;
return materialize_address(global_type[id], global_marker[id]);
}
eprintf("unresolved identifier: %s\n", name);
exit(1);
@ -619,65 +824,33 @@ int asm_label(int label) {
return label;
}
int is_not_reusable(int rs1, int expected_type) {
return indirection[rs1] || local_marker[rs1] != MARKER_TEMP || local_type[rs1] != expected_type;
}
int asm_r(const char* op, int rs1) {
load(0, rs1);
printf(" %s t0, t0\n", op);
int rd = rs1;
if (is_not_reusable(rs1, TYPE_INT)) {
rd = next_reg(TYPE_INT);
}
store_t0(rd);
return rd;
}
int asm_r_arith(const char* op, int rs1) {
if (local_type[rs1] & TYPE_PTR_MASK) {
if (reg_type[rs1] & TYPE_PTR_MASK) {
eprintf("pointer cannot be arithmetically operated by %s\n", op);
exit(1);
}
return asm_r(op, rs1);
}
int asm_rr(const char* op, int rs1, int rs2) {
load(0, rs1);
load(1, rs2);
printf(" %s t0, t0, t1\n", op);
int rd = rs1;
if (is_not_reusable(rd, TYPE_INT)) {
rd = rs2;
if (is_not_reusable(rd, TYPE_INT)) {
rd = next_reg(TYPE_INT);
}
}
store_t0(rd);
return rd;
return asm_r(TYPE_INT, op, rs1);
}
int asm_rr_arith(const char* op, int rs1, int rs2) {
if (local_type[rs1] & TYPE_PTR_MASK || local_type[rs2] & TYPE_PTR_MASK) {
if (reg_type[rs1] & TYPE_PTR_MASK || reg_type[rs2] & TYPE_PTR_MASK) {
eprintf("pointer cannot be arithmetically operated by %s\n", op);
exit(1);
}
return asm_rr(op, rs1, rs2);
return asm_rr(TYPE_INT, op, rs1, rs2);
}
int asm_rr_cmp(const char* op, int rs1, int rs2) {
// since NULL is virtually 0, it is considered valid example of a pointer comparing with an integer
return asm_rr(op, rs1, rs2);
// since NULL is virtually 0, it is considered a valid example of a pointer comparing with an integer
return asm_rr(TYPE_INT, op, rs1, rs2);
}
void asm_beqz(int rs1, int label) {
load(0, rs1);
printf(" beqz t0, L%d\n", label);
_asm_branch("beqz", rs1, label);
}
void asm_bnez(int rs1, int label) {
load(0, rs1);
printf(" bnez t0, L%d\n", label);
_asm_branch("bnez", rs1, label);
}
void asm_j(int label) {
@ -714,15 +887,9 @@ int step_of(int type) {
return 1;
}
void asm_shift_t0(const char* op, int type) {
if (type == TYPE_INT_PTR) {
printf(" %s t0, t0, 2\n", op);
}
}
int asm_add(int lhs, int rhs) {
int type1 = local_type[lhs] & TYPE_PTR_MASK;
int type2 = local_type[rhs] & TYPE_PTR_MASK;
int type1 = reg_type[lhs] & TYPE_PTR_MASK;
int type2 = reg_type[rhs] & TYPE_PTR_MASK;
if (type1 != type2) {
int ptr;
int idx;
@ -733,27 +900,26 @@ int asm_add(int lhs, int rhs) {
ptr = rhs;
idx = lhs;
}
int ptr_type = local_type[ptr];
int ptr_type = reg_type[ptr];
if (ptr_type == TYPE_VOID_PTR) {
eprintf("void pointer cannot be arithmetically operated\n");
exit(1);
}
load(0, idx);
load(1, ptr);
asm_shift_t0("slli", ptr_type);
printf(" add t0, t0, t1\n");
return materialize_t0(ptr_type);
int offset = next_reg(TYPE_INT);
int shift = 2 * (ptr_type == TYPE_INT_PTR);
_asm_ri("slli", offset, idx, shift);
return asm_rr(ptr_type, "add", ptr, offset);
}
if (type1 && type2) {
eprintf("operands of addition cannot be both pointers\n");
exit(1);
}
return asm_rr("add", lhs, rhs);
return asm_rr(TYPE_INT, "add", lhs, rhs);
}
int asm_sub(int lhs, int rhs) {
int lhs_type = local_type[lhs];
int rhs_type = local_type[rhs];
int lhs_type = reg_type[lhs];
int rhs_type = reg_type[rhs];
int type1 = lhs_type & TYPE_PTR_MASK;
int type2 = rhs_type & TYPE_PTR_MASK;
if (type1 && type2) {
@ -765,17 +931,36 @@ int asm_sub(int lhs, int rhs) {
eprintf("void pointer cannot be arithmetically operated\n");
exit(1);
}
load(0, lhs);
load(1, rhs);
printf(" sub t0, t0, t1\n");
asm_shift_t0("srai", lhs_type);
int difference = asm_rr(TYPE_INT, "sub", lhs, rhs);
int shift = 2 * (lhs_type == TYPE_INT_PTR);
_asm_ri("slli", REG_T0, difference, shift);
return materialize_t0(TYPE_INT);
}
if (type1) {
int neg = asm_r_arith("neg", rhs);
return asm_add(lhs, neg);
}
return asm_rr("sub", lhs, rhs);
return asm_rr_arith("sub", lhs, rhs);
}
int dereference(int reg) {
if (indirection[reg]) {
load(reg, reg);
} else {
indirection[reg] = 1;
}
reg_type[reg] = reg_type[reg] & ~TYPE_PTR_MASK;
return reg;
}
int addressof(int reg) {
if (indirection[reg] && !(reg_type[reg] & TYPE_PTR_MASK)) {
reg_type[reg] = reg_type[reg] | TYPE_PTR_MASK;
indirection[reg] = 0;
} else {
printf("cannot take address of this expression");
}
return reg;
}
// parser
@ -811,10 +996,11 @@ int parse_function_call(int id) {
}
}
for (int i = 0; i < arg; ++i) {
load(0, args[i]);
printf(" mv a%d, t0\n", i);
asm_mv(i + REG_A0, args[i]);
}
// TODO saved by caller
printf(" call %s\n", name);
// TODO saved by caller
int type = global_type[id];
if (type != TYPE_VOID) {
printf(" mv t0, a0\n");
@ -855,20 +1041,16 @@ int parse_postfix_expr() {
while (1) {
next_token();
if (token_type == TOKEN_INC) {
int type = local_type[lhs];
int type = reg_type[lhs];
int reg = next_reg(type);
load(0, lhs);
store_t0(reg);
printf(" addi t0, t0, %d\n", step_of(type));
store_t0(lhs);
asm_mv(reg, lhs);
_asm_ri("addi", lhs, lhs, step_of(type));
lhs = reg;
} else if (token_type == TOKEN_DEC) {
int type = local_type[lhs];
int type = reg_type[lhs];
int reg = next_reg(type);
load(0, lhs);
store_t0(reg);
printf(" addi t0, t0, -%d\n", step_of(type));
store_t0(lhs);
asm_mv(reg, lhs);
_asm_ri("addi", lhs, lhs, -step_of(type));
lhs = reg;
} else if (token_type == TOKEN_BRACKET_LEFT) {
int rhs = parse_expr();
@ -886,16 +1068,15 @@ int parse_prefix_expr() {
next_token();
if (token_type == TOKEN_AND) {
int reg = parse_postfix_expr();
int type = local_type[reg];
int type = reg_type[reg];
if (type & TYPE_PTR_MASK) {
eprintf("cannot take address of a pointer\n");
exit(1);
}
load_address(0, reg);
return materialize_t0(type | TYPE_PTR_MASK);
return addressof(reg);
} else if (token_type == TOKEN_STAR) {
int reg = parse_postfix_expr();
int type = local_type[reg];
int type = reg_type[reg];
if (!(type & TYPE_PTR_MASK)) {
eprintf("cannot dereference a non-pointer\n");
exit(1);
@ -904,8 +1085,7 @@ int parse_prefix_expr() {
eprintf("cannot dereference void pointer\n");
exit(1);
}
load(0, reg);
return dereference(materialize_t0(type));
return dereference(reg);
} else if (token_type == TOKEN_MINUS) {
int reg = parse_postfix_expr();
return asm_r_arith("neg", reg);
@ -914,18 +1094,14 @@ int parse_prefix_expr() {
return asm_r_arith("not", reg);
} else if (token_type == TOKEN_NOT) {
int reg = parse_postfix_expr();
return asm_r("seqz", reg);
return asm_r(TYPE_INT, "seqz", reg);
} else if (token_type == TOKEN_INC) {
int reg = parse_postfix_expr();
load(0, reg);
printf(" addi t0, t0, %d\n", step_of(local_type[reg]));
store_t0(reg);
_asm_ri("addi", reg, reg, step_of(reg_type[reg]));
return reg;
} else if (token_type == TOKEN_DEC) {
int reg = parse_postfix_expr();
load(0, reg);
printf(" addi t0, t0, -%d\n", step_of(local_type[reg]));
store_t0(reg);
_asm_ri("addi", reg, reg, -step_of(reg_type[reg]));
return reg;
} else {
unget_token();
@ -1003,11 +1179,11 @@ int parse_cmp_expr() {
} else if (token_type == TOKEN_LE) {
int rhs = parse_shift_expr();
int sgt = asm_rr_cmp("sgt", lhs, rhs);
lhs = asm_r("seqz", sgt);
lhs = asm_r(TYPE_INT, "seqz", sgt);
} else if (token_type == TOKEN_GE) {
int rhs = parse_shift_expr();
int slt = asm_rr_cmp("slt", lhs, rhs);
lhs = asm_r("seqz", slt);
lhs = asm_r(TYPE_INT, "seqz", slt);
} else {
unget_token();
break;
@ -1023,11 +1199,11 @@ int parse_eq_expr() {
if (token_type == TOKEN_EQ) {
int rhs = parse_cmp_expr();
int xor0 = asm_rr_cmp("xor", lhs, rhs);
lhs = asm_r("seqz", xor0);
lhs = asm_r(TYPE_INT, "seqz", xor0);
} else if (token_type == TOKEN_NE) {
int rhs = parse_cmp_expr();
int xor0 = asm_rr_cmp("xor", lhs, rhs);
lhs = asm_r("snez", xor0);
lhs = asm_r(TYPE_INT, "snez", xor0);
} else {
unget_token();
break;
@ -1084,48 +1260,58 @@ int parse_bitwise_or_expr() {
int parse_logical_and_expr() {
int lhs = parse_bitwise_or_expr();
int label = next_label();
int label_used = 0;
int logical = 0;
int label;
int result;
while (1) {
next_token();
if (token_type == TOKEN_LAND) {
lhs = asm_r("snez", lhs);
asm_beqz(lhs, label);
if (!logical) {
logical = 1;
label = next_label();
result = next_reg(TYPE_INT);
_asm_r("snez", result, lhs);
}
asm_beqz(result, label);
int rhs = parse_bitwise_or_expr();
rhs = asm_r("snez", rhs);
lhs = asm_rr("and", lhs, rhs);
label_used = 1;
_asm_r("snez", result, rhs);
} else {
unget_token();
break;
}
}
if (label_used) {
if (logical) {
asm_label(label);
return result;
}
return lhs;
}
int parse_logical_or_expr() {
int lhs = parse_logical_and_expr();
int label = next_label();
int label_used = 0;
int logical = 0;
int label;
int result;
while (1) {
next_token();
if (token_type == TOKEN_LOR) {
lhs = asm_r("snez", lhs);
asm_bnez(lhs, label);
if (!logical) {
logical = 1;
label = next_label();
result = next_reg(TYPE_INT);
_asm_r("snez", result, lhs);
}
asm_bnez(result, label);
int rhs = parse_logical_and_expr();
rhs = asm_r("snez", rhs);
lhs = asm_rr("or", lhs, rhs);
label_used = 1;
_asm_r("snez", result, rhs);
} else {
unget_token();
break;
}
}
if (label_used) {
if (logical) {
asm_label(label);
return result;
}
return lhs;
}
@ -1135,8 +1321,7 @@ int parse_assign_expr() {
next_token();
if (token_type == TOKEN_ASSIGN) {
int rhs = parse_assign_expr();
load(0, rhs);
store_t0(lhs);
asm_mv(lhs, rhs);
return lhs;
} else {
unget_token();
@ -1165,10 +1350,9 @@ void parse_local_variable(int type) {
int size = token_data;
expect_token(TOKEN_BRACKET_RIGHT);
declare_local_array(id, type, size);
next_token();
} else {
declare_local(id, type);
return;
}
int slot = declare_local(id, type);
if (token_type == TOKEN_SEMICOLON) {
unget_token();
return;
@ -1176,8 +1360,13 @@ void parse_local_variable(int type) {
unget_token();
expect_token(TOKEN_ASSIGN);
int reg = parse_expr();
load(0, reg);
store_t0(local_table[id]);
if (type != reg_type[reg]) {
eprintf("type mismatch in assignment\n");
exit(1);
}
asm_mv(REG_T0, reg);
load_local_address(REG_T2, slot);
printf(" %s t0, 0(t2)\n", store_op_of_type(type));
}
void parse_stmt();
@ -1290,9 +1479,8 @@ void parse_stmt() {
return;
}
unget_token();
int reg = parse_expr();
load(0, reg);
printf(" mv a0, t0\n");
int rs1 = parse_expr();
asm_mv(REG_A0, rs1);
asm_j(epilog_label);
} else if (token_type == TOKEN_BREAK) {
int label = asm_get_break_label();
@ -1335,7 +1523,7 @@ void parse_function(const char* name) {
}
int arg_type = parse_type();
if (arg_type < 0 || arg_type == TYPE_VOID) {
eprintf("unexpected a non-void argument type");
eprintf("unexpected a non-void argument type: %d\n", arg_type);
exit(1);
}
expect_token(TOKEN_ID);
@ -1392,16 +1580,23 @@ void parse_function(const char* name) {
asm_addi("sp", "sp", -frame_size);
asm_sd("ra", frame_size - 8, "sp");
asm_sd("fp", frame_size - 16, "sp");
for (int reg = REG_S2; reg <= REG_S11; ++reg) {
asm_sd(reg_name(reg), frame_size - reg * 8 + 15 * 8, "sp");
}
asm_addi("fp", "sp", frame_size);
for (int i = 0; i < arg; ++i) {
printf(" mv t0, a%d\n", i);
store_t0(args[i]);
int slot = args[i];
load_local_address(REG_T2, slot);
printf(" %s a%d, 0(t2)\n", store_op_of_type(local_type[slot]), i);
}
asm_j(label);
// epilog
asm_label(epilog_label);
asm_ld("fp", frame_size - 16, "sp");
asm_ld("ra", frame_size - 8, "sp");
asm_ld("fp", frame_size - 16, "sp");
for (int reg = REG_S2; reg <= REG_S11; ++reg) {
asm_ld(reg_name(reg), frame_size - reg * 8 + 15 * 8, "sp");
}
asm_addi("sp", "sp", frame_size);
printf(" ret\n");
}
@ -1496,6 +1691,7 @@ void dump_string_table() {
}
int main() {
eprintf("start compiling...\n");
parse_top_level();
dump_string_table();
return 0;

View File

@ -5,7 +5,7 @@ gcc ../boot.c ../boot-lib.c -o gcc.out &&
riscv64-linux-gnu-gcc-12 -static boot1.s ../boot-lib.c -o boot1.out &&
qemu-riscv64 boot1.out < boot-all.c > boot2.s &&
riscv64-linux-gnu-gcc-12 -static boot2.s ../boot-lib.c -o boot2.out &&
qemu-riscv64 boot2.out < boot-all.c > boot3.s &&
qemu-riscv64 boot2.out < boot-all.c > boot3.s
cmp --silent boot1.s boot2.s && echo "boot1.s == boot2.s" || echo "boot1.s != boot2.s"
cmp --silent boot2.s boot3.s && echo "boot2.s == boot3.s" || echo "boot2.s != boot3.s"
cmp --silent boot1.s boot3.s && echo "boot1.s == boot3.s" || echo "boot1.s != boot3.s"