Add compiler optimizations for #1163 - eachp

Should result in much better bytecode in the simple case.
This commit is contained in:
Calvin Rose 2023-05-31 12:26:27 -05:00
parent 77189b6e66
commit 644ac8caf8
2 changed files with 81 additions and 22 deletions

View File

@ -445,7 +445,7 @@
,(case kind
:each ~(,in ,ds ,k)
:keys k
:pairs ~(,tuple ,k (,in ,ds ,k))))
:pairs ~[,k (,in ,ds ,k)]))
,;body
(set ,k (,next ,ds ,k))))))

View File

@ -306,12 +306,16 @@ static JanetSlot janetc_varset(JanetFopts opts, int32_t argn, const Janet *argv)
}
/* Add attributes to a global def or var table */
static JanetTable *handleattr(JanetCompiler *c, int32_t argn, const Janet *argv) {
static JanetTable *handleattr(JanetCompiler *c, const char *kind, int32_t argn, const Janet *argv) {
int32_t i;
JanetTable *tab = janet_table(2);
const char *binding_name = janet_type(argv[0]) == JANET_SYMBOL
? ((const char *)janet_unwrap_symbol(argv[0]))
: "<multiple bindings>";
if (argn < 2) {
janetc_error(c, janet_formatc("expected at least 2 arguments to %s", kind));
return NULL;
}
for (i = 1; i < argn - 1; i++) {
Janet attr = argv[i];
switch (janet_type(attr)) {
@ -335,18 +339,51 @@ static JanetTable *handleattr(JanetCompiler *c, int32_t argn, const Janet *argv)
return tab;
}
static JanetSlot dohead(const char *kind, JanetCompiler *c, JanetFopts opts, Janet *head, int32_t argn, const Janet *argv) {
typedef struct SlotHeadPair {
Janet lhs;
JanetSlot rhs;
} SlotHeadPair;
SlotHeadPair *dohead_destructure(JanetCompiler *c, SlotHeadPair *into, JanetFopts opts, Janet lhs, Janet rhs) {
/* Detect if we can do an optimization to avoid some allocations */
int can_destructure_lhs = janet_checktype(lhs, JANET_TUPLE)
|| janet_checktype(lhs, JANET_ARRAY);
int rhs_is_indexed = janet_checktype(rhs, JANET_ARRAY)
|| (janet_checktype(rhs, JANET_TUPLE) && (janet_tuple_flag(janet_unwrap_tuple(rhs)) & JANET_TUPLE_FLAG_BRACKETCTOR));
uint32_t has_drop = opts.flags & JANET_FOPTS_DROP;
JanetFopts subopts = janetc_fopts_default(c);
JanetSlot ret;
if (argn < 2) {
janetc_error(c, janet_formatc("expected at least 2 arguments to %s", kind));
return janetc_cslot(janet_wrap_nil());
}
*head = argv[0];
subopts.flags = opts.flags & ~(JANET_FOPTS_TAIL | JANET_FOPTS_DROP);
if (has_drop && can_destructure_lhs && rhs_is_indexed) {
/* Code is of the form (def [a b] [1 2]), avoid the allocation of two tuples */
JanetView view_lhs, view_rhs;
janet_indexed_view(lhs, &view_lhs.items, &view_lhs.len);
janet_indexed_view(rhs, &view_rhs.items, &view_rhs.len);
int found_amp = 0;
for (int32_t i = 0; i < view_lhs.len; i++) {
if (janet_symeq(view_lhs.items[i], "&")) {
found_amp = 1;
/* Good error will be generated later. */
break;
}
}
if (!found_amp) {
for (int32_t i = 0; i < view_lhs.len; i++) {
Janet sub_rhs = view_rhs.len <= i ? janet_wrap_nil() : view_rhs.items[i];
into = dohead_destructure(c, into, subopts, view_lhs.items[i], sub_rhs);
}
return into;
}
}
/* No optimization, do the simple way */
subopts.hint = opts.hint;
ret = janetc_value(subopts, argv[argn - 1]);
return ret;
JanetSlot ret = janetc_value(subopts, rhs);
SlotHeadPair shp = {lhs, ret};
janet_v_push(into, shp);
return into;
}
/* Def or var a symbol in a local scope */
@ -412,12 +449,23 @@ static int varleaf(
static JanetSlot janetc_var(JanetFopts opts, int32_t argn, const Janet *argv) {
JanetCompiler *c = opts.compiler;
Janet head;
JanetTable *attr_table = handleattr(c, argn, argv);
JanetSlot ret = dohead("var", c, opts, &head, argn, argv);
if (c->result.status == JANET_COMPILE_ERROR)
JanetTable *attr_table = handleattr(c, "var", argn, argv);
if (c->result.status == JANET_COMPILE_ERROR) {
return janetc_cslot(janet_wrap_nil());
destructure(c, argv[0], ret, varleaf, attr_table);
}
SlotHeadPair *into = NULL;
into = dohead_destructure(c, into, opts, argv[0], argv[argn - 1]);
if (c->result.status == JANET_COMPILE_ERROR) {
janet_v_free(into);
return janetc_cslot(janet_wrap_nil());
}
JanetSlot ret;
janet_assert(janet_v_count(into) > 0, "bad destructure");
for (int32_t i = 0; i < janet_v_count(into); i++) {
destructure(c, into[i].lhs, into[i].rhs, varleaf, attr_table);
ret = into[i].rhs;
}
janet_v_free(into);
return ret;
}
@ -461,13 +509,24 @@ static int defleaf(
static JanetSlot janetc_def(JanetFopts opts, int32_t argn, const Janet *argv) {
JanetCompiler *c = opts.compiler;
Janet head;
opts.flags &= ~JANET_FOPTS_HINT;
JanetTable *attr_table = handleattr(c, argn, argv);
JanetSlot ret = dohead("def", c, opts, &head, argn, argv);
if (c->result.status == JANET_COMPILE_ERROR)
JanetTable *attr_table = handleattr(c, "def", argn, argv);
if (c->result.status == JANET_COMPILE_ERROR) {
return janetc_cslot(janet_wrap_nil());
destructure(c, argv[0], ret, defleaf, attr_table);
}
opts.flags &= ~JANET_FOPTS_HINT;
SlotHeadPair *into = NULL;
into = dohead_destructure(c, into, opts, argv[0], argv[argn - 1]);
if (c->result.status == JANET_COMPILE_ERROR) {
janet_v_free(into);
return janetc_cslot(janet_wrap_nil());
}
JanetSlot ret;
janet_assert(janet_v_count(into) > 0, "bad destructure");
for (int32_t i = 0; i < janet_v_count(into); i++) {
destructure(c, into[i].lhs, into[i].rhs, defleaf, attr_table);
ret = into[i].rhs;
}
janet_v_free(into);
return ret;
}