bc: implement pass-by-reference code from upstream

function                                             old     new   delta
zxc_program_popResultAndCopyToVar                    298     493    +195
bc_vec_pushIndex                                       -      75     +75
zxc_vm_process                                       859     928     +69
xc_program_dereference                                 -      66     +66
bc_vec_npush                                           -      65     +65
zbc_num_s                                            239     249     +10
zxc_program_num                                     1024    1032      +8
zbc_num_divmod                                       150     156      +6
xc_program_search                                    143     146      +3
zxc_program_assign                                   392     389      -3
zdc_program_execStr                                  520     517      -3
xc_program_pushVar                                   198     195      -3
zxc_program_exec                                    4101    4092      -9
zbc_program_call                                     318     308     -10
zbc_func_insert                                      120     104     -16
zbc_parse_stmt_possibly_auto                        1460    1439     -21
bc_vec_push                                           53      12     -41
xc_parse_pushIndex                                    61      18     -43
------------------------------------------------------------------------------
(add/remove: 3/0 grow/shrink: 6/9 up/down: 497/-149)          Total: 348 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2019-01-25 14:24:03 +01:00
parent db5a6daa7f
commit 53799506ac
3 changed files with 504 additions and 87 deletions

View File

@ -4,8 +4,8 @@
* Adapted from https://github.com/gavinhoward/bc
* Original code copyright (c) 2018 Gavin D. Howard and contributors.
*/
//TODO: GNU extensions:
// support "define f(*param[])" - "pass array by reference" syntax
//TODO:
// maybe implement a^b for non-integer b?
#define DEBUG_LEXER 0
#define DEBUG_COMPILE 0
@ -380,6 +380,12 @@ typedef struct BcInstPtr {
size_t inst_idx;
} BcInstPtr;
typedef enum BcType {
BC_TYPE_VAR,
BC_TYPE_ARRAY,
BC_TYPE_REF,
} BcType;
typedef enum BcLexType {
XC_LEX_EOF,
XC_LEX_INVALID,
@ -1092,15 +1098,25 @@ static void bc_vec_pop_all(BcVec *v)
bc_vec_npop(v, v->len);
}
static size_t bc_vec_push(BcVec *v, const void *data)
static size_t bc_vec_npush(BcVec *v, size_t n, const void *data)
{
size_t len = v->len;
if (len >= v->cap) bc_vec_grow(v, 1);
memmove(v->v + (v->size * len), data, v->size);
v->len++;
if (len + n > v->cap) bc_vec_grow(v, n);
memmove(v->v + (v->size * len), data, v->size * n);
v->len = len + n;
return len;
}
static size_t bc_vec_push(BcVec *v, const void *data)
{
return bc_vec_npush(v, 1, data);
//size_t len = v->len;
//if (len >= v->cap) bc_vec_grow(v, 1);
//memmove(v->v + (v->size * len), data, v->size);
//v->len = len + 1;
//return len;
}
// G.prog.results often needs "pop old operand, push result" idiom.
// Can do this without a few extra ops
static size_t bc_result_pop_and_push(const void *data)
@ -3528,14 +3544,14 @@ static void xc_parse_pushName(char *name)
// (The above describes 32-bit case).
#define SMALL_INDEX_LIMIT (0x100 - sizeof(size_t))
static void xc_parse_pushIndex(size_t idx)
static void bc_vec_pushIndex(BcVec *v, size_t idx)
{
size_t mask;
unsigned amt;
dbg_lex("%s:%d pushing index %zd", __func__, __LINE__, idx);
if (idx < SMALL_INDEX_LIMIT) {
xc_parse_push(idx);
bc_vec_pushByte(v, idx);
return;
}
@ -3548,14 +3564,19 @@ static void xc_parse_pushIndex(size_t idx)
}
// amt is at least 1 here - "one byte of length data follows"
xc_parse_push((SMALL_INDEX_LIMIT - 1) + amt);
bc_vec_pushByte(v, (SMALL_INDEX_LIMIT - 1) + amt);
do {
xc_parse_push((unsigned char)idx);
bc_vec_pushByte(v, (unsigned char)idx);
idx >>= 8;
} while (idx != 0);
}
static void xc_parse_pushIndex(size_t idx)
{
bc_vec_pushIndex(&G.prs.func->code, idx);
}
static void xc_parse_pushInst_and_Index(unsigned inst, size_t idx)
{
xc_parse_push(inst);
@ -4340,7 +4361,7 @@ static BC_STATUS zbc_parse_break_or_continue(BcLexType type)
}
#define zbc_parse_break_or_continue(...) (zbc_parse_break_or_continue(__VA_ARGS__) COMMA_SUCCESS)
static BC_STATUS zbc_func_insert(BcFunc *f, char *name, bool var)
static BC_STATUS zbc_func_insert(BcFunc *f, char *name, BcType type)
{
BcId *autoid;
BcId a;
@ -4349,13 +4370,13 @@ static BC_STATUS zbc_func_insert(BcFunc *f, char *name, bool var)
autoid = (void*)f->autos.v;
for (i = 0; i < f->autos.len; i++, autoid++) {
if (strcmp(name, autoid->name) == 0
&& var == autoid->idx
&& type == (BcType) autoid->idx
) {
RETURN_STATUS(bc_error("duplicate function parameter or auto name"));
}
}
a.idx = var;
a.idx = type;
a.name = name;
bc_vec_push(&f->autos, &a);
@ -4368,7 +4389,7 @@ static BC_STATUS zbc_parse_funcdef(void)
{
BcParse *p = &G.prs;
BcStatus s;
bool var, comma, voidfunc;
bool comma, voidfunc;
char *name;
dbg_lex_enter("%s:%d entered", __func__, __LINE__);
@ -4406,6 +4427,16 @@ static BC_STATUS zbc_parse_funcdef(void)
comma = false;
while (p->lex != BC_LEX_RPAREN) {
BcType t = BC_TYPE_VAR;
if (p->lex == XC_LEX_OP_MULTIPLY) {
t = BC_TYPE_REF;
s = zxc_lex_next();
if (s) RETURN_STATUS(s);
s = zbc_POSIX_does_not_allow("references");
if (s) RETURN_STATUS(s);
}
if (p->lex != XC_LEX_NAME)
RETURN_STATUS(bc_error_bad_function_definition());
@ -4415,9 +4446,8 @@ static BC_STATUS zbc_parse_funcdef(void)
s = zxc_lex_next();
if (s) goto err;
var = p->lex != BC_LEX_LBRACKET;
if (!var) {
if (p->lex == BC_LEX_LBRACKET) {
if (t == BC_TYPE_VAR) t = BC_TYPE_ARRAY;
s = zxc_lex_next();
if (s) goto err;
@ -4429,6 +4459,10 @@ static BC_STATUS zbc_parse_funcdef(void)
s = zxc_lex_next();
if (s) goto err;
}
else if (t == BC_TYPE_REF) {
s = bc_error_at("vars can't be references");
goto err;
}
comma = p->lex == BC_LEX_COMMA;
if (comma) {
@ -4436,7 +4470,7 @@ static BC_STATUS zbc_parse_funcdef(void)
if (s) goto err;
}
s = zbc_func_insert(p->func, name, var);
s = zbc_func_insert(p->func, name, t);
if (s) goto err;
}
@ -4488,7 +4522,7 @@ static BC_STATUS zbc_parse_auto(void)
if (s) RETURN_STATUS(s);
for (;;) {
bool var;
BcType t;
if (p->lex != XC_LEX_NAME)
RETURN_STATUS(bc_error_at("bad 'auto' syntax"));
@ -4497,8 +4531,9 @@ static BC_STATUS zbc_parse_auto(void)
s = zxc_lex_next();
if (s) goto err;
var = (p->lex != BC_LEX_LBRACKET);
if (!var) {
t = BC_TYPE_VAR;
if (p->lex == BC_LEX_LBRACKET) {
t = BC_TYPE_ARRAY;
s = zxc_lex_next();
if (s) goto err;
@ -4510,7 +4545,7 @@ static BC_STATUS zbc_parse_auto(void)
if (s) goto err;
}
s = zbc_func_insert(p->func, name, var);
s = zbc_func_insert(p->func, name, t);
if (s) goto err;
if (p->lex == XC_LEX_NLINE
@ -5119,12 +5154,64 @@ static BC_STATUS zdc_parse_exprs_until_eof(void)
#define STACK_HAS_MORE_THAN(s, n) ((s)->len > ((size_t)(n)))
#define STACK_HAS_EQUAL_OR_MORE_THAN(s, n) ((s)->len >= ((size_t)(n)))
static BcVec* xc_program_search(char *id, bool var)
static size_t xc_program_index(char *code, size_t *bgn)
{
unsigned char *bytes = (void*)(code + *bgn);
unsigned amt;
unsigned i;
size_t res;
amt = *bytes++;
if (amt < SMALL_INDEX_LIMIT) {
*bgn += 1;
return amt;
}
amt -= (SMALL_INDEX_LIMIT - 1); // amt is 1 or more here
*bgn += amt + 1;
res = 0;
i = 0;
do {
res |= (size_t)(*bytes++) << i;
i += 8;
} while (--amt != 0);
return res;
}
static char *xc_program_name(char *code, size_t *bgn)
{
code += *bgn;
*bgn += strlen(code) + 1;
return xstrdup(code);
}
static BcVec* xc_program_dereference(BcVec *vec)
{
BcVec *v;
size_t vidx, nidx, i = 0;
//assert(vec->size == sizeof(uint8_t));
vidx = xc_program_index(vec->v, &i);
nidx = xc_program_index(vec->v, &i);
v = bc_vec_item(&G.prog.arrs, vidx);
v = bc_vec_item(v, nidx);
//assert(v->size != sizeof(uint8_t));
return v;
}
static BcVec* xc_program_search(char *id, BcType type)
{
BcId e, *ptr;
BcVec *v, *map;
size_t i;
int new;
bool var = (type == BC_TYPE_VAR);
v = var ? &G.prog.vars : &G.prog.arrs;
map = var ? &G.prog.var_map : &G.prog.arr_map;
@ -5178,17 +5265,20 @@ static BC_STATUS zxc_program_num(BcResult *r, BcNum **num)
case XC_RESULT_VAR:
case XC_RESULT_ARRAY:
case XC_RESULT_ARRAY_ELEM: {
BcVec *v;
void *p;
v = xc_program_search(r->d.id.name, r->t == XC_RESULT_VAR);
// dc variables are all stacks, so here we have this:
p = bc_vec_top(v);
// TODO: eliminate these stacks for bc-only config?
BcType type = (r->t == XC_RESULT_VAR) ? BC_TYPE_VAR : BC_TYPE_ARRAY;
BcVec *v = xc_program_search(r->d.id.name, type);
void *p = bc_vec_top(v);
if (r->t == XC_RESULT_ARRAY_ELEM) {
size_t idx = r->d.id.idx;
v = p;
if (v->len <= r->d.id.idx)
bc_array_expand(v, r->d.id.idx + 1);
*num = bc_vec_item(v, r->d.id.idx);
if (v->size == sizeof(uint8_t))
v = xc_program_dereference(v);
//assert(v->size == sizeof(BcNum));
if (v->len <= idx)
bc_array_expand(v, idx + 1);
*num = bc_vec_item(v, idx);
} else {
*num = p;
}
@ -5347,39 +5437,6 @@ static BC_STATUS zxc_program_read(void)
}
#define zxc_program_read(...) (zxc_program_read(__VA_ARGS__) COMMA_SUCCESS)
static size_t xc_program_index(char *code, size_t *bgn)
{
unsigned char *bytes = (void*)(code + *bgn);
unsigned amt;
unsigned i;
size_t res;
amt = *bytes++;
if (amt < SMALL_INDEX_LIMIT) {
*bgn += 1;
return amt;
}
amt -= (SMALL_INDEX_LIMIT - 1); // amt is 1 or more here
*bgn += amt + 1;
res = 0;
i = 0;
do {
res |= (size_t)(*bytes++) << i;
i += 8;
} while (--amt != 0);
return res;
}
static char *xc_program_name(char *code, size_t *bgn)
{
code += *bgn;
*bgn += strlen(code) + 1;
return xstrdup(code);
}
static void xc_program_printString(const char *str)
{
#if ENABLE_DC
@ -5755,43 +5812,81 @@ static BC_STATUS zdc_program_assignStr(BcResult *r, BcVec *v, bool push)
#define zdc_program_assignStr(...) (zdc_program_assignStr(__VA_ARGS__) COMMA_SUCCESS)
#endif // ENABLE_DC
static BC_STATUS zxc_program_popResultAndCopyToVar(char *name, bool var)
static BC_STATUS zxc_program_popResultAndCopyToVar(char *name, BcType t)
{
BcStatus s;
BcResult *ptr, r;
BcVec *v;
BcVec *vec;
BcNum *n;
bool var = (t == BC_TYPE_VAR);
if (!STACK_HAS_MORE_THAN(&G.prog.results, 0))
RETURN_STATUS(bc_error_stack_has_too_few_elements());
ptr = bc_vec_top(&G.prog.results);
if ((ptr->t == XC_RESULT_ARRAY) != !var)
if ((ptr->t == XC_RESULT_ARRAY) == var)
RETURN_STATUS(bc_error_variable_is_wrong_type());
v = xc_program_search(name, var);
vec = xc_program_search(name, t);
#if ENABLE_DC
if (ptr->t == XC_RESULT_STR && !var)
RETURN_STATUS(bc_error_variable_is_wrong_type());
if (ptr->t == XC_RESULT_STR)
RETURN_STATUS(zdc_program_assignStr(ptr, v, true));
if (ptr->t == XC_RESULT_STR) {
if (!var)
RETURN_STATUS(bc_error_variable_is_wrong_type());
RETURN_STATUS(zdc_program_assignStr(ptr, vec, true));
}
#endif
s = zxc_program_num(ptr, &n);
if (s) RETURN_STATUS(s);
// Do this once more to make sure that pointers were not invalidated.
v = xc_program_search(name, var);
vec = xc_program_search(name, t);
if (var) {
bc_num_init_DEF_SIZE(&r.d.n);
bc_num_copy(&r.d.n, n);
} else {
bc_array_init(&r.d.v, true);
bc_array_copy(&r.d.v, (BcVec *) n);
}
BcVec *v = (BcVec*) n;
bool ref, ref_size;
bc_vec_push(v, &r.d);
ref = (v->size == sizeof(BcVec) && t != BC_TYPE_ARRAY);
ref_size = (v->size == sizeof(uint8_t));
if (ref || (ref_size && t == BC_TYPE_REF)) {
bc_vec_init(&r.d.v, sizeof(uint8_t), NULL);
if (ref) {
size_t vidx, idx;
BcId id;
id.name = ptr->d.id.name;
v = xc_program_search(ptr->d.id.name, BC_TYPE_REF);
// Make sure the pointer was not invalidated.
vec = xc_program_search(name, t);
vidx = bc_map_find_exact(&G.prog.arr_map, &id);
//assert(vidx != BC_VEC_INVALID_IDX);
vidx = ((BcId*) bc_vec_item(&G.prog.arr_map, vidx))->idx;
idx = v->len - 1;
bc_vec_pushIndex(&r.d.v, vidx);
bc_vec_pushIndex(&r.d.v, idx);
}
// If we get here, we are copying a ref to a ref.
else bc_vec_npush(&r.d.v, v->len, v->v);
// We need to return early.
goto ret;
}
if (ref_size && t != BC_TYPE_REF)
v = xc_program_dereference(v);
bc_array_init(&r.d.v, true);
bc_array_copy(&r.d.v, v);
}
ret:
bc_vec_push(vec, &r.d);
bc_vec_pop(&G.prog.results);
RETURN_STATUS(s);
@ -5818,7 +5913,7 @@ static BC_STATUS zxc_program_assign(char inst)
if (left->t != XC_RESULT_VAR)
RETURN_STATUS(bc_error_variable_is_wrong_type());
v = xc_program_search(left->d.id.name, true);
v = xc_program_search(left->d.id.name, BC_TYPE_VAR);
RETURN_STATUS(zdc_program_assignStr(right, v, false));
}
@ -5897,7 +5992,7 @@ static BC_STATUS xc_program_pushVar(char *code, size_t *bgn,
#if ENABLE_DC
if (pop || copy) {
BcVec *v = xc_program_search(name, true);
BcVec *v = xc_program_search(name, BC_TYPE_VAR);
BcNum *num = bc_vec_top(v);
free(name);
@ -6014,16 +6109,19 @@ static BC_STATUS zbc_program_call(char *code, size_t *idx)
for (i = 0; i < nparams; ++i) {
BcResult *arg;
BcStatus s;
bool arr;
a = bc_vec_item(&func->autos, nparams - 1 - i);
arg = bc_vec_top(&G.prog.results);
if ((!a->idx) != (arg->t == XC_RESULT_ARRAY) // array/variable mismatch
arr = (a->idx == BC_TYPE_ARRAY || a->idx == BC_TYPE_REF);
if (arr != (arg->t == XC_RESULT_ARRAY) // array/variable mismatch
// || arg->t == XC_RESULT_STR - impossible, f("str") is not a legal syntax (strings are not bc expressions)
) {
RETURN_STATUS(bc_error_variable_is_wrong_type());
}
s = zxc_program_popResultAndCopyToVar(a->name, a->idx);
s = zxc_program_popResultAndCopyToVar(a->name, (BcType) a->idx);
if (s) RETURN_STATUS(s);
}
@ -6031,12 +6129,13 @@ static BC_STATUS zbc_program_call(char *code, size_t *idx)
for (; i < func->autos.len; i++, a++) {
BcVec *v;
v = xc_program_search(a->name, a->idx);
if (a->idx) {
v = xc_program_search(a->name, (BcType) a->idx);
if (a->idx == BC_TYPE_VAR) {
BcNum n2;
bc_num_init_DEF_SIZE(&n2);
bc_vec_push(v, &n2);
} else {
//assert(a->idx == BC_TYPE_ARRAY);
BcVec v2;
bc_array_init(&v2, true);
bc_vec_push(v, &v2);
@ -6087,7 +6186,7 @@ static BC_STATUS zbc_program_return(char inst)
a = (void*)f->autos.v;
for (i = 0; i < f->autos.len; i++, a++) {
BcVec *v;
v = xc_program_search(a->name, a->idx);
v = xc_program_search(a->name, (BcType) a->idx);
bc_vec_pop(v);
}
@ -6399,7 +6498,7 @@ static BC_STATUS zdc_program_execStr(char *code, size_t *bgn, bool cond)
if (exec) {
BcVec *v;
v = xc_program_search(name, true);
v = xc_program_search(name, BC_TYPE_VAR);
n = bc_vec_top(v);
}
@ -6724,7 +6823,7 @@ static BC_STATUS zxc_program_exec(void)
}
case DC_INST_PUSH_TO_VAR: {
char *name = xc_program_name(code, &ip->inst_idx);
s = zxc_program_popResultAndCopyToVar(name, true);
s = zxc_program_popResultAndCopyToVar(name, BC_TYPE_VAR);
free(name);
break;
}

106
testsuite/bc_references.bc Normal file
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@ -0,0 +1,106 @@
define printarray(a[], len) {
auto i
for (i = 0; i < len; ++i) {
a[i]
}
}
define a2(a[], len) {
auto i
for (i = 0; i < len; ++i) {
a[i] = a[i] * a[i]
}
printarray(a[], len)
}
define a4(a__[], len) {
auto i
for (i = 0; i < len; ++i) {
a__[i] = a__[i] * a__[i]
}
printarray(a__[], len)
}
define a6(*a__[], len) {
auto i
for (i = 0; i < len; ++i) {
a__[i] = a__[i] * a__[i]
}
printarray(a__[], len)
}
define a1(*a[], len) {
auto i
for (i = 0; i < len; ++i) {
a[i] = i
}
a2(a[], len)
printarray(a[], len)
}
define a3(*a__[], len) {
auto i
for (i = 0; i < len; ++i) {
a__[i] = i
}
a4(a__[], len)
printarray(a__[], len)
}
define a5(*a__[], len) {
auto i
for (i = 0; i < len; ++i) {
a__[i] = i
}
a2(a__[], len)
printarray(a__[], len)
}
define a7(*a__[], len) {
auto i
for (i = 0; i < len; ++i) {
a__[i] = i
}
a6(a__[], len)
printarray(a__[], len)
}
len = 16
a1(a[], len)
printarray(a[], len)
a3(a[], len)
printarray(a[], len)
a5(a[], len)
printarray(a[], len)
a7(a[], len)
printarray(a[], len)
halt

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