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mirror of https://github.com/janet-lang/janet synced 2026-04-11 01:11:26 +00:00
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janet/src/core/bytecode.c
Calvin Rose ec5a78d3dc Add pointer shift option for more nanboxing on arm64.
We now try to detect this and do it by default. This is important
as arm64 becomes more common and dominant.
2026-03-23 13:57:43 -05:00

536 lines
19 KiB
C

/*
* Copyright (c) 2026 Calvin Rose
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#ifndef JANET_AMALG
#include "features.h"
#include <janet.h>
#include "gc.h"
#include "util.h"
#include "regalloc.h"
#endif
/* Look up table for instructions */
const enum JanetInstructionType janet_instructions[JOP_INSTRUCTION_COUNT] = {
JINT_0, /* JOP_NOOP, */
JINT_S, /* JOP_ERROR, */
JINT_ST, /* JOP_TYPECHECK, */
JINT_S, /* JOP_RETURN, */
JINT_0, /* JOP_RETURN_NIL, */
JINT_SSI, /* JOP_ADD_IMMEDIATE, */
JINT_SSS, /* JOP_ADD, */
JINT_SSI, /* JOP_SUBTRACT_IMMEDIATE, */
JINT_SSS, /* JOP_SUBTRACT, */
JINT_SSI, /* JOP_MULTIPLY_IMMEDIATE, */
JINT_SSS, /* JOP_MULTIPLY, */
JINT_SSI, /* JOP_DIVIDE_IMMEDIATE, */
JINT_SSS, /* JOP_DIVIDE, */
JINT_SSS, /* JOP_DIVIDE_FLOOR */
JINT_SSS, /* JOP_MODULO, */
JINT_SSS, /* JOP_REMAINDER, */
JINT_SSS, /* JOP_BAND, */
JINT_SSS, /* JOP_BOR, */
JINT_SSS, /* JOP_BXOR, */
JINT_SS, /* JOP_BNOT, */
JINT_SSS, /* JOP_SHIFT_LEFT, */
JINT_SSI, /* JOP_SHIFT_LEFT_IMMEDIATE, */
JINT_SSS, /* JOP_SHIFT_RIGHT, */
JINT_SSI, /* JOP_SHIFT_RIGHT_IMMEDIATE, */
JINT_SSS, /* JOP_SHIFT_RIGHT_UNSIGNED, */
JINT_SSU, /* JOP_SHIFT_RIGHT_UNSIGNED_IMMEDIATE, */
JINT_SS, /* JOP_MOVE_FAR, */
JINT_SS, /* JOP_MOVE_NEAR, */
JINT_L, /* JOP_JUMP, */
JINT_SL, /* JOP_JUMP_IF, */
JINT_SL, /* JOP_JUMP_IF_NOT, */
JINT_SL, /* JOP_JUMP_IF_NIL, */
JINT_SL, /* JOP_JUMP_IF_NOT_NIL, */
JINT_SSS, /* JOP_GREATER_THAN, */
JINT_SSI, /* JOP_GREATER_THAN_IMMEDIATE, */
JINT_SSS, /* JOP_LESS_THAN, */
JINT_SSI, /* JOP_LESS_THAN_IMMEDIATE, */
JINT_SSS, /* JOP_EQUALS, */
JINT_SSI, /* JOP_EQUALS_IMMEDIATE, */
JINT_SSS, /* JOP_COMPARE, */
JINT_S, /* JOP_LOAD_NIL, */
JINT_S, /* JOP_LOAD_TRUE, */
JINT_S, /* JOP_LOAD_FALSE, */
JINT_SI, /* JOP_LOAD_INTEGER, */
JINT_SC, /* JOP_LOAD_CONSTANT, */
JINT_SES, /* JOP_LOAD_UPVALUE, */
JINT_S, /* JOP_LOAD_SELF, */
JINT_SES, /* JOP_SET_UPVALUE, */
JINT_SD, /* JOP_CLOSURE, */
JINT_S, /* JOP_PUSH, */
JINT_SS, /* JOP_PUSH_2, */
JINT_SSS, /* JOP_PUSH_3, */
JINT_S, /* JOP_PUSH_ARRAY, */
JINT_SS, /* JOP_CALL, */
JINT_S, /* JOP_TAILCALL, */
JINT_SSS, /* JOP_RESUME, */
JINT_SSU, /* JOP_SIGNAL, */
JINT_SSS, /* JOP_PROPAGATE */
JINT_SSS, /* JOP_IN, */
JINT_SSS, /* JOP_GET, */
JINT_SSS, /* JOP_PUT, */
JINT_SSU, /* JOP_GET_INDEX, */
JINT_SSU, /* JOP_PUT_INDEX, */
JINT_SS, /* JOP_LENGTH */
JINT_S, /* JOP_MAKE_ARRAY */
JINT_S, /* JOP_MAKE_BUFFER */
JINT_S, /* JOP_MAKE_STRING */
JINT_S, /* JOP_MAKE_STRUCT */
JINT_S, /* JOP_MAKE_TABLE */
JINT_S, /* JOP_MAKE_TUPLE */
JINT_S, /* JOP_MAKE_BRACKET_TUPLE */
JINT_SSS, /* JOP_GREATER_THAN_EQUAL */
JINT_SSS, /* JOP_LESS_THAN_EQUAL */
JINT_SSS, /* JOP_NEXT */
JINT_SSS, /* JOP_NOT_EQUALS, */
JINT_SSI, /* JOP_NOT_EQUALS_IMMEDIATE, */
JINT_SSS /* JOP_CANCEL, */
};
/* Remove all noops while preserving jumps and debugging information.
* Useful as part of a filtering compiler pass. */
void janet_bytecode_remove_noops(JanetFuncDef *def) {
/* Get an instruction rewrite map so we can rewrite jumps */
uint32_t *pc_map = janet_smalloc(sizeof(uint32_t) * (1 + def->bytecode_length));
uint32_t new_bytecode_length = 0;
for (int32_t i = 0; i < def->bytecode_length; i++) {
uint32_t instr = def->bytecode[i];
uint32_t opcode = instr & 0x7F;
pc_map[i] = new_bytecode_length;
if (opcode != JOP_NOOP) {
new_bytecode_length++;
}
}
pc_map[def->bytecode_length] = new_bytecode_length;
/* Linear scan rewrite bytecode and sourcemap. Also fix jumps. */
int32_t j = 0;
for (int32_t i = 0; i < def->bytecode_length; i++) {
uint32_t instr = def->bytecode[i];
uint32_t opcode = instr & 0x7F;
int32_t old_jump_target = 0;
int32_t new_jump_target = 0;
switch (opcode) {
case JOP_NOOP:
continue;
case JOP_JUMP:
/* relative pc is in DS field of instruction */
old_jump_target = i + (((int32_t)instr) >> 8);
new_jump_target = pc_map[old_jump_target];
instr += (uint32_t)(new_jump_target - old_jump_target + (i - j)) << 8;
break;
case JOP_JUMP_IF:
case JOP_JUMP_IF_NIL:
case JOP_JUMP_IF_NOT:
case JOP_JUMP_IF_NOT_NIL:
/* relative pc is in ES field of instruction */
old_jump_target = i + (((int32_t)instr) >> 16);
new_jump_target = pc_map[old_jump_target];
instr += (uint32_t)(new_jump_target - old_jump_target + (i - j)) << 16;
break;
default:
break;
}
def->bytecode[j] = instr;
if (def->sourcemap != NULL) {
def->sourcemap[j] = def->sourcemap[i];
}
j++;
}
/* Rewrite symbolmap */
for (int32_t i = 0; i < def->symbolmap_length; i++) {
JanetSymbolMap *sm = def->symbolmap + i;
/* Don't rewrite upvalue mappings */
if (sm->birth_pc < UINT32_MAX) {
sm->birth_pc = pc_map[sm->birth_pc];
sm->death_pc = pc_map[sm->death_pc];
}
}
def->bytecode_length = new_bytecode_length;
def->bytecode = janet_realloc(def->bytecode, def->bytecode_length * sizeof(uint32_t));
janet_sfree(pc_map);
}
/* Remove redundant loads, moves and other instructions if possible and convert them to
* noops. Input is assumed valid bytecode. */
void janet_bytecode_movopt(JanetFuncDef *def) {
JanetcRegisterAllocator ra;
int recur = 1;
/* Iterate this until no more instructions can be removed. */
while (recur) {
janetc_regalloc_init(&ra);
/* Look for slots that have writes but no reads (and aren't in the closure bitset). */
if (def->closure_bitset != NULL) {
for (int32_t i = 0; i < def->slotcount; i++) {
int32_t index = i >> 5;
uint32_t mask = 1U << (((uint32_t) i) & 31);
if (def->closure_bitset[index] & mask) {
janetc_regalloc_touch(&ra, i);
}
}
}
#define AA ((instr >> 8) & 0xFF)
#define BB ((instr >> 16) & 0xFF)
#define CC (instr >> 24)
#define DD (instr >> 8)
#define EE (instr >> 16)
/* Check reads and writes */
for (int32_t i = 0; i < def->bytecode_length; i++) {
uint32_t instr = def->bytecode[i];
switch (instr & 0x7F) {
/* Group instructions my how they read from slots */
/* No reads or writes */
default:
janet_assert(0, "unhandled instruction");
case JOP_JUMP:
case JOP_NOOP:
case JOP_RETURN_NIL:
/* Write A */
case JOP_LOAD_INTEGER:
case JOP_LOAD_CONSTANT:
case JOP_LOAD_UPVALUE:
case JOP_CLOSURE:
/* Write D */
case JOP_LOAD_NIL:
case JOP_LOAD_TRUE:
case JOP_LOAD_FALSE:
case JOP_LOAD_SELF:
break;
case JOP_MAKE_ARRAY:
case JOP_MAKE_BUFFER:
case JOP_MAKE_STRING:
case JOP_MAKE_STRUCT:
case JOP_MAKE_TABLE:
case JOP_MAKE_TUPLE:
case JOP_MAKE_BRACKET_TUPLE:
/* Reads from the stack, don't remove */
janetc_regalloc_touch(&ra, DD);
break;
/* Read A */
case JOP_ERROR:
case JOP_TYPECHECK:
case JOP_JUMP_IF:
case JOP_JUMP_IF_NOT:
case JOP_JUMP_IF_NIL:
case JOP_JUMP_IF_NOT_NIL:
case JOP_SET_UPVALUE:
/* Write E, Read A */
case JOP_MOVE_FAR:
janetc_regalloc_touch(&ra, AA);
break;
/* Read B */
case JOP_SIGNAL:
/* Write A, Read B */
case JOP_ADD_IMMEDIATE:
case JOP_SUBTRACT_IMMEDIATE:
case JOP_MULTIPLY_IMMEDIATE:
case JOP_DIVIDE_IMMEDIATE:
case JOP_SHIFT_LEFT_IMMEDIATE:
case JOP_SHIFT_RIGHT_IMMEDIATE:
case JOP_SHIFT_RIGHT_UNSIGNED_IMMEDIATE:
case JOP_GREATER_THAN_IMMEDIATE:
case JOP_LESS_THAN_IMMEDIATE:
case JOP_EQUALS_IMMEDIATE:
case JOP_NOT_EQUALS_IMMEDIATE:
case JOP_GET_INDEX:
janetc_regalloc_touch(&ra, BB);
break;
/* Read D */
case JOP_RETURN:
case JOP_PUSH:
case JOP_PUSH_ARRAY:
case JOP_TAILCALL:
janetc_regalloc_touch(&ra, DD);
break;
/* Write A, Read E */
case JOP_MOVE_NEAR:
case JOP_LENGTH:
case JOP_BNOT:
case JOP_CALL:
janetc_regalloc_touch(&ra, EE);
break;
/* Read A, B */
case JOP_PUT_INDEX:
janetc_regalloc_touch(&ra, AA);
janetc_regalloc_touch(&ra, BB);
break;
/* Read A, E */
case JOP_PUSH_2:
janetc_regalloc_touch(&ra, AA);
janetc_regalloc_touch(&ra, EE);
break;
/* Read B, C */
case JOP_PROPAGATE:
/* Write A, Read B and C */
case JOP_BAND:
case JOP_BOR:
case JOP_BXOR:
case JOP_ADD:
case JOP_SUBTRACT:
case JOP_MULTIPLY:
case JOP_DIVIDE:
case JOP_DIVIDE_FLOOR:
case JOP_MODULO:
case JOP_REMAINDER:
case JOP_SHIFT_LEFT:
case JOP_SHIFT_RIGHT:
case JOP_SHIFT_RIGHT_UNSIGNED:
case JOP_GREATER_THAN:
case JOP_LESS_THAN:
case JOP_EQUALS:
case JOP_COMPARE:
case JOP_IN:
case JOP_GET:
case JOP_GREATER_THAN_EQUAL:
case JOP_LESS_THAN_EQUAL:
case JOP_NOT_EQUALS:
case JOP_CANCEL:
case JOP_RESUME:
case JOP_NEXT:
janetc_regalloc_touch(&ra, BB);
janetc_regalloc_touch(&ra, CC);
break;
/* Read A, B, C */
case JOP_PUT:
case JOP_PUSH_3:
janetc_regalloc_touch(&ra, AA);
janetc_regalloc_touch(&ra, BB);
janetc_regalloc_touch(&ra, CC);
break;
}
}
/* Iterate and set noops on instructions that make writes that no one ever reads.
* Only set noops for instructions with no side effects - moves, loads, etc. that can't
* raise errors (outside of systemic errors like oom or stack overflow). */
recur = 0;
for (int32_t i = 0; i < def->bytecode_length; i++) {
uint32_t instr = def->bytecode[i];
switch (instr & 0x7F) {
default:
break;
/* Write D */
case JOP_LOAD_NIL:
case JOP_LOAD_TRUE:
case JOP_LOAD_FALSE:
case JOP_LOAD_SELF:
case JOP_MAKE_ARRAY:
case JOP_MAKE_TUPLE:
case JOP_MAKE_BRACKET_TUPLE: {
if (!janetc_regalloc_check(&ra, DD)) {
def->bytecode[i] = JOP_NOOP;
recur = 1;
}
}
break;
/* Write E, Read A */
case JOP_MOVE_FAR: {
if (!janetc_regalloc_check(&ra, EE)) {
def->bytecode[i] = JOP_NOOP;
recur = 1;
}
}
break;
/* Write A, Read E */
case JOP_MOVE_NEAR:
/* Write A, Read B */
case JOP_GET_INDEX:
/* Write A */
case JOP_LOAD_INTEGER:
case JOP_LOAD_CONSTANT:
case JOP_LOAD_UPVALUE:
case JOP_CLOSURE: {
if (!janetc_regalloc_check(&ra, AA)) {
def->bytecode[i] = JOP_NOOP;
recur = 1;
}
}
break;
}
}
janetc_regalloc_deinit(&ra);
#undef AA
#undef BB
#undef CC
#undef DD
#undef EE
}
}
/* Verify some bytecode */
int janet_verify(JanetFuncDef *def) {
int vargs = !!(def->flags & JANET_FUNCDEF_FLAG_VARARG);
int32_t i;
int32_t maxslot = def->arity + vargs;
int32_t sc = def->slotcount;
if (def->bytecode_length == 0) return 1;
if (maxslot > sc) return 2;
/* Verify each instruction */
for (i = 0; i < def->bytecode_length; i++) {
uint32_t instr = def->bytecode[i];
/* Check for invalid instructions */
if ((instr & 0x7F) >= JOP_INSTRUCTION_COUNT) {
return 3;
}
enum JanetInstructionType type = janet_instructions[instr & 0x7F];
switch (type) {
case JINT_0:
continue;
case JINT_S: {
if ((int32_t)(instr >> 8) >= sc) return 4;
continue;
}
case JINT_SI:
case JINT_SU:
case JINT_ST: {
if ((int32_t)((instr >> 8) & 0xFF) >= sc) return 4;
continue;
}
case JINT_L: {
int32_t jumpdest = i + (((int32_t)instr) >> 8);
if (jumpdest < 0 || jumpdest >= def->bytecode_length) return 5;
continue;
}
case JINT_SS: {
if ((int32_t)((instr >> 8) & 0xFF) >= sc ||
(int32_t)(instr >> 16) >= sc) return 4;
continue;
}
case JINT_SSI:
case JINT_SSU: {
if ((int32_t)((instr >> 8) & 0xFF) >= sc ||
(int32_t)((instr >> 16) & 0xFF) >= sc) return 4;
continue;
}
case JINT_SL: {
int32_t jumpdest = i + (((int32_t)instr) >> 16);
if ((int32_t)((instr >> 8) & 0xFF) >= sc) return 4;
if (jumpdest < 0 || jumpdest >= def->bytecode_length) return 5;
continue;
}
case JINT_SSS: {
if (((int32_t)(instr >> 8) & 0xFF) >= sc ||
((int32_t)(instr >> 16) & 0xFF) >= sc ||
((int32_t)(instr >> 24) & 0xFF) >= sc) return 4;
continue;
}
case JINT_SD: {
if ((int32_t)((instr >> 8) & 0xFF) >= sc) return 4;
if ((int32_t)(instr >> 16) >= def->defs_length) return 6;
continue;
}
case JINT_SC: {
if ((int32_t)((instr >> 8) & 0xFF) >= sc) return 4;
if ((int32_t)(instr >> 16) >= def->constants_length) return 7;
continue;
}
case JINT_SES: {
/* How can we check the last slot index? We need info parent funcdefs. Resort
* to runtime checks for now. Maybe invalid upvalue references could be defaulted
* to nil? (don't commit to this in the long term, though) */
if ((int32_t)((instr >> 8) & 0xFF) >= sc) return 4;
if ((int32_t)((instr >> 16) & 0xFF) >= def->environments_length) return 8;
continue;
}
}
}
/* Verify last instruction is either a jump, return, return-nil, or tailcall. Eventually,
* some real flow analysis would be ideal, but this should be very effective. Will completely
* prevent running over the end of bytecode. However, valid functions with dead code will
* be rejected. */
{
uint32_t lastop = def->bytecode[def->bytecode_length - 1] & 0xFF;
switch (lastop) {
default:
return 9;
case JOP_RETURN:
case JOP_RETURN_NIL:
case JOP_JUMP:
case JOP_ERROR:
case JOP_TAILCALL:
break;
}
}
return 0;
}
/* Allocate an empty funcdef. This function may have added functionality
* as commonalities between asm and compile arise. */
JanetFuncDef *janet_funcdef_alloc(void) {
JanetFuncDef *def = janet_gcalloc(JANET_MEMORY_FUNCDEF, sizeof(JanetFuncDef));
def->environments = NULL;
def->constants = NULL;
def->bytecode = NULL;
def->closure_bitset = NULL;
def->flags = 0;
def->slotcount = 0;
def->symbolmap = NULL;
def->arity = 0;
def->min_arity = 0;
def->max_arity = INT32_MAX;
def->source = NULL;
def->sourcemap = NULL;
def->name = NULL;
def->defs = NULL;
def->defs_length = 0;
def->constants_length = 0;
def->bytecode_length = 0;
def->environments_length = 0;
def->symbolmap_length = 0;
def->named_args_count = 0;
return def;
}
/* Create a simple closure from a funcdef */
JanetFunction *janet_thunk(JanetFuncDef *def) {
JanetFunction *func = janet_gcalloc(JANET_MEMORY_FUNCTION, sizeof(JanetFunction));
func->def = def;
janet_assert(def->environments_length == 0, "tried to create thunk that needs upvalues");
return func;
}