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[WIP] Auto-extend live-ranges #11880

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17 changes: 4 additions & 13 deletions Zend/Optimizer/block_pass.c
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Original file line number Diff line number Diff line change
Expand Up @@ -945,7 +945,7 @@ static void assemble_code_blocks(zend_cfg *cfg, zend_op_array *op_array, zend_op
if (b->len == 0) {
continue;
}
if (b->flags & (ZEND_BB_REACHABLE|ZEND_BB_UNREACHABLE_FREE)) {
if (b->flags & ZEND_BB_REACHABLE) {
opline = op_array->opcodes + b->start + b->len - 1;
if (opline->opcode == ZEND_JMP) {
zend_basic_block *next = b + 1;
Expand Down Expand Up @@ -983,7 +983,7 @@ static void assemble_code_blocks(zend_cfg *cfg, zend_op_array *op_array, zend_op

/* Copy code of reachable blocks into a single buffer */
for (b = blocks; b < end; b++) {
if (b->flags & (ZEND_BB_REACHABLE|ZEND_BB_UNREACHABLE_FREE)) {
if (b->flags & ZEND_BB_REACHABLE) {
memcpy(opline, op_array->opcodes + b->start, b->len * sizeof(zend_op));
b->start = opline - new_opcodes;
opline += b->len;
Expand Down Expand Up @@ -1100,7 +1100,7 @@ static void assemble_code_blocks(zend_cfg *cfg, zend_op_array *op_array, zend_op
/* rebuild map (just for printing) */
memset(cfg->map, -1, sizeof(int) * op_array->last);
for (int n = 0; n < cfg->blocks_count; n++) {
if (cfg->blocks[n].flags & (ZEND_BB_REACHABLE|ZEND_BB_UNREACHABLE_FREE)) {
if (cfg->blocks[n].flags & ZEND_BB_REACHABLE) {
cfg->map[cfg->blocks[n].start] = n;
}
}
Expand Down Expand Up @@ -1725,16 +1725,7 @@ void zend_optimize_cfg(zend_op_array *op_array, zend_optimizer_ctx *ctx)

/* Eliminate NOPs */
for (b = blocks; b < end; b++) {
if (b->flags & ZEND_BB_UNREACHABLE_FREE) {
/* In unreachable_free blocks only preserve loop var frees. */
for (uint32_t i = b->start; i < b->start + b->len; i++) {
zend_op *opline = &op_array->opcodes[i];
if (!zend_optimizer_is_loop_var_free(opline)) {
MAKE_NOP(opline);
}
}
}
if (b->flags & (ZEND_BB_REACHABLE|ZEND_BB_UNREACHABLE_FREE)) {
if (b->flags & ZEND_BB_REACHABLE) {
strip_nops(op_array, b);
}
}
Expand Down
12 changes: 1 addition & 11 deletions Zend/Optimizer/dfa_pass.c
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Expand Up @@ -138,21 +138,14 @@ static void zend_ssa_remove_nops(zend_op_array *op_array, zend_ssa *ssa, zend_op
}

for (b = blocks; b < blocks_end; b++) {
if (b->flags & (ZEND_BB_REACHABLE|ZEND_BB_UNREACHABLE_FREE)) {
if (b->flags & ZEND_BB_REACHABLE) {
if (b->len) {
uint32_t new_start, old_end;
while (i < b->start) {
shiftlist[i] = i - target;
i++;
}

if (b->flags & ZEND_BB_UNREACHABLE_FREE) {
/* Only keep the FREE for the loop var */
ZEND_ASSERT(op_array->opcodes[b->start].opcode == ZEND_FREE
|| op_array->opcodes[b->start].opcode == ZEND_FE_FREE);
b->len = 1;
}

new_start = target;
old_end = b->start + b->len;
while (i < old_end) {
Expand Down Expand Up @@ -757,9 +750,6 @@ static int zend_dfa_optimize_jmps(zend_op_array *op_array, zend_ssa *ssa)

while (next_block_num < ssa->cfg.blocks_count
&& !(ssa->cfg.blocks[next_block_num].flags & ZEND_BB_REACHABLE)) {
if (ssa->cfg.blocks[next_block_num].flags & ZEND_BB_UNREACHABLE_FREE) {
can_follow = 0;
}
next_block_num++;
}

Expand Down
34 changes: 2 additions & 32 deletions Zend/Optimizer/zend_cfg.c
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Expand Up @@ -196,33 +196,6 @@ static void zend_mark_reachable_blocks(const zend_op_array *op_array, zend_cfg *
}
} while (changed);
}

if (cfg->flags & ZEND_FUNC_FREE_LOOP_VAR) {
zend_basic_block *b;
int j;
uint32_t *block_map = cfg->map;

/* Mark blocks that are unreachable, but free a loop var created in a reachable block. */
for (b = blocks; b < blocks + cfg->blocks_count; b++) {
if (b->flags & ZEND_BB_REACHABLE) {
continue;
}

for (j = b->start; j < b->start + b->len; j++) {
zend_op *opline = &op_array->opcodes[j];
if (zend_optimizer_is_loop_var_free(opline)) {
zend_op *def_opline = zend_optimizer_get_loop_var_def(op_array, opline);
if (def_opline) {
uint32_t def_block = block_map[def_opline - op_array->opcodes];
if (blocks[def_block].flags & ZEND_BB_REACHABLE) {
b->flags |= ZEND_BB_UNREACHABLE_FREE;
break;
}
}
}
}
}
}
}
/* }}} */

Expand Down Expand Up @@ -305,9 +278,7 @@ ZEND_API void zend_build_cfg(zend_arena **arena, const zend_op_array *op_array,
case ZEND_MATCH_ERROR:
case ZEND_EXIT:
case ZEND_THROW:
/* Don't treat THROW as terminator if it's used in expression context,
* as we may lose live ranges when eliminating unreachable code. */
if (opline->extended_value != ZEND_THROW_IS_EXPR && i + 1 < op_array->last) {
if (i + 1 < op_array->last) {
BB_START(i + 1);
}
break;
Expand Down Expand Up @@ -430,8 +401,7 @@ ZEND_API void zend_build_cfg(zend_arena **arena, const zend_op_array *op_array,
case ZEND_FREE:
case ZEND_FE_FREE:
if (zend_optimizer_is_loop_var_free(opline)
&& ((opline-1)->opcode != ZEND_MATCH_ERROR
|| (opline-1)->extended_value != ZEND_THROW_IS_EXPR)) {
&& ((opline-1)->opcode != ZEND_MATCH_ERROR)) {
BB_START(i);
flags |= ZEND_FUNC_FREE_LOOP_VAR;
}
Expand Down
3 changes: 1 addition & 2 deletions Zend/Optimizer/zend_cfg.h
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Original file line number Diff line number Diff line change
Expand Up @@ -29,15 +29,14 @@
#define ZEND_BB_CATCH (1<<6) /* start of catch block */
#define ZEND_BB_FINALLY (1<<7) /* start of finally block */
#define ZEND_BB_FINALLY_END (1<<8) /* end of finally block */
#define ZEND_BB_UNREACHABLE_FREE (1<<11) /* unreachable loop free */
#define ZEND_BB_RECV_ENTRY (1<<12) /* RECV entry */

#define ZEND_BB_LOOP_HEADER (1<<16)
#define ZEND_BB_IRREDUCIBLE_LOOP (1<<17)

#define ZEND_BB_REACHABLE (1U<<31)

#define ZEND_BB_PROTECTED (ZEND_BB_ENTRY|ZEND_BB_RECV_ENTRY|ZEND_BB_TRY|ZEND_BB_CATCH|ZEND_BB_FINALLY|ZEND_BB_FINALLY_END|ZEND_BB_UNREACHABLE_FREE)
#define ZEND_BB_PROTECTED (ZEND_BB_ENTRY|ZEND_BB_RECV_ENTRY|ZEND_BB_TRY|ZEND_BB_CATCH|ZEND_BB_FINALLY|ZEND_BB_FINALLY_END)

typedef struct _zend_basic_block {
int *successors; /* successor block indices */
Expand Down
3 changes: 0 additions & 3 deletions Zend/Optimizer/zend_dump.c
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Expand Up @@ -803,9 +803,6 @@ static void zend_dump_block_info(const zend_cfg *cfg, int n, uint32_t dump_flags
if (!(dump_flags & ZEND_DUMP_HIDE_UNREACHABLE) && !(b->flags & ZEND_BB_REACHABLE)) {
fprintf(stderr, " unreachable");
}
if (b->flags & ZEND_BB_UNREACHABLE_FREE) {
fprintf(stderr, " unreachable_free");
}
if (b->flags & ZEND_BB_LOOP_HEADER) {
fprintf(stderr, " loop_header");
}
Expand Down
4 changes: 2 additions & 2 deletions Zend/Optimizer/zend_optimizer.c
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Expand Up @@ -1027,7 +1027,7 @@ static void zend_optimize(zend_op_array *op_array,
*/
if ((ZEND_OPTIMIZER_PASS_9 & ctx->optimization_level) &&
!(ZEND_OPTIMIZER_PASS_7 & ctx->optimization_level)) {
zend_optimize_temporary_variables(op_array, ctx);
// zend_optimize_temporary_variables(op_array, ctx);
if (ctx->debug_level & ZEND_DUMP_AFTER_PASS_9) {
zend_dump_op_array(op_array, 0, "after pass 9", NULL);
}
Expand Down Expand Up @@ -1536,7 +1536,7 @@ ZEND_API void zend_optimize_script(zend_script *script, zend_long optimization_l

if (ZEND_OPTIMIZER_PASS_9 & optimization_level) {
for (i = 0; i < call_graph.op_arrays_count; i++) {
zend_optimize_temporary_variables(call_graph.op_arrays[i], &ctx);
// zend_optimize_temporary_variables(call_graph.op_arrays[i], &ctx);
if (debug_level & ZEND_DUMP_AFTER_PASS_9) {
zend_dump_op_array(call_graph.op_arrays[i], 0, "after pass 9", NULL);
}
Expand Down
12 changes: 2 additions & 10 deletions Zend/zend_compile.c
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Expand Up @@ -5181,10 +5181,8 @@ static void zend_compile_throw(znode *result, zend_ast *ast) /* {{{ */
znode expr_node;
zend_compile_expr(&expr_node, expr_ast);

zend_op *opline = zend_emit_op(NULL, ZEND_THROW, &expr_node, NULL);
zend_emit_op(NULL, ZEND_THROW, &expr_node, NULL);
if (result) {
/* Mark this as an "expression throw" for opcache. */
opline->extended_value = ZEND_THROW_IS_EXPR;
result->op_type = IS_CONST;
ZVAL_TRUE(&result->u.constant);
}
Expand Down Expand Up @@ -5947,10 +5945,6 @@ static void zend_compile_match(znode *result, zend_ast *ast)
if (opline->op1_type == IS_CONST) {
Z_TRY_ADDREF_P(CT_CONSTANT(opline->op1));
}
if (arms->children == 0) {
/* Mark this as an "expression throw" for opcache. */
opline->extended_value = ZEND_THROW_IS_EXPR;
}
}

for (uint32_t i = 0; i < arms->children; ++i) {
Expand Down Expand Up @@ -9432,10 +9426,8 @@ static void zend_compile_exit(znode *result, zend_ast *ast) /* {{{ */
expr_node.op_type = IS_UNUSED;
}

zend_op *opline = zend_emit_op(NULL, ZEND_EXIT, &expr_node, NULL);
zend_emit_op(NULL, ZEND_EXIT, &expr_node, NULL);
if (result) {
/* Mark this as an "expression throw" for opcache. */
opline->extended_value = ZEND_THROW_IS_EXPR;
result->op_type = IS_CONST;
ZVAL_TRUE(&result->u.constant);
}
Expand Down
2 changes: 0 additions & 2 deletions Zend/zend_compile.h
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Expand Up @@ -1021,8 +1021,6 @@ ZEND_API zend_string *zend_type_to_string(zend_type type);
#define ZEND_SEND_BY_REF 1u
#define ZEND_SEND_PREFER_REF 2u

#define ZEND_THROW_IS_EXPR 1u

#define ZEND_FCALL_MAY_HAVE_EXTRA_NAMED_PARAMS 1

/* The send mode, the is_variadic, the is_promoted, and the is_tentative flags are stored as part of zend_type */
Expand Down
41 changes: 35 additions & 6 deletions Zend/zend_opcode.c
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Expand Up @@ -746,6 +746,9 @@ static void emit_live_range(
case ZEND_DECLARE_ANON_CLASS:
/* FAST_CALLs don't have to be destroyed. */
case ZEND_FAST_CALL:
/* JMP_NULL only define null, false and true. */
case ZEND_JMP_NULL:
case ZEND_JMP_SET:
return;
case ZEND_BEGIN_SILENCE:
kind = ZEND_LIVE_SILENCE;
Expand Down Expand Up @@ -912,6 +915,9 @@ static void swap_live_range(zend_live_range *a, zend_live_range *b) {
b->end = tmp;
}

#define LIVE_RANGE_VAR_UNUSED ((uint32_t) -1)
#define LIVE_RANGE_VAR_DEFINED ((uint32_t) -2)

static void zend_calc_live_ranges(
zend_op_array *op_array, zend_needs_live_range_cb needs_live_range) {
uint32_t opnum = op_array->last;
Expand All @@ -928,12 +934,35 @@ static void zend_calc_live_ranges(

if ((opline->result_type & (IS_TMP_VAR|IS_VAR)) && !is_fake_def(opline)) {
uint32_t var_num = EX_VAR_TO_NUM(opline->result.var) - var_offset;
// FIXME: Outdated comment
/* Defs without uses can occur for two reasons: Either because the result is
* genuinely unused (e.g. omitted FREE opcode for an unused boolean result), or
* because there are multiple defining opcodes (e.g. JMPZ_EX and QM_ASSIGN), in
* which case the last one starts the live range. As such, we can simply ignore
* missing uses here. */
if (EXPECTED(last_use[var_num] != (uint32_t) -1)) {
if (UNEXPECTED(last_use[var_num] == LIVE_RANGE_VAR_UNUSED)) {
// FIXME: Make sure not to insert unnecessary live-ranges. But I think this is already handled.
/* Find the innermost try/catch that we are inside of. */
uint32_t live_range_end = (uint32_t) -1;
for (uint32_t i = 0; i < op_array->last_try_catch; i++) {
zend_try_catch_element *try_catch = &op_array->try_catch_array[i];
if (opnum < try_catch->try_op) {
break;
}
if (opnum < try_catch->catch_op) {
live_range_end = try_catch->catch_op;
} else if (opnum < try_catch->finally_end) {
live_range_end = try_catch->finally_end;
}
}
if (live_range_end == (uint32_t) -1) {
live_range_end = op_array->last;
}
if (opnum + 1 != live_range_end) {
emit_live_range(op_array, var_num, opnum, live_range_end, needs_live_range);
}
last_use[var_num] = LIVE_RANGE_VAR_DEFINED;
} else if (last_use[var_num] != LIVE_RANGE_VAR_DEFINED) {
/* Skip trivial live-range */
if (opnum + 1 != last_use[var_num]) {
uint32_t num;
Expand All @@ -948,13 +977,13 @@ static void zend_calc_live_ranges(
#endif
emit_live_range(op_array, var_num, num, last_use[var_num], needs_live_range);
}
last_use[var_num] = (uint32_t) -1;
last_use[var_num] = LIVE_RANGE_VAR_DEFINED;
}
}

if ((opline->op1_type & (IS_TMP_VAR|IS_VAR))) {
uint32_t var_num = EX_VAR_TO_NUM(opline->op1.var) - var_offset;
if (EXPECTED(last_use[var_num] == (uint32_t) -1)) {
if (EXPECTED(last_use[var_num] == LIVE_RANGE_VAR_UNUSED || last_use[var_num] == LIVE_RANGE_VAR_DEFINED)) {
if (EXPECTED(!keeps_op1_alive(opline))) {
/* OP_DATA is really part of the previous opcode. */
last_use[var_num] = opnum - (opline->opcode == ZEND_OP_DATA);
Expand All @@ -966,14 +995,14 @@ static void zend_calc_live_ranges(
if (UNEXPECTED(opline->opcode == ZEND_FE_FETCH_R
|| opline->opcode == ZEND_FE_FETCH_RW)) {
/* OP2 of FE_FETCH is actually a def, not a use. */
if (last_use[var_num] != (uint32_t) -1) {
if (last_use[var_num] != LIVE_RANGE_VAR_UNUSED && last_use[var_num] != LIVE_RANGE_VAR_DEFINED) {
if (opnum + 1 != last_use[var_num]) {
emit_live_range(
op_array, var_num, opnum, last_use[var_num], needs_live_range);
}
last_use[var_num] = (uint32_t) -1;
last_use[var_num] = LIVE_RANGE_VAR_DEFINED;
}
} else if (EXPECTED(last_use[var_num] == (uint32_t) -1)) {
} else if (EXPECTED(last_use[var_num] == LIVE_RANGE_VAR_UNUSED || last_use[var_num] == LIVE_RANGE_VAR_DEFINED)) {
#if 1
/* OP_DATA uses only op1 operand */
ZEND_ASSERT(opline->opcode != ZEND_OP_DATA);
Expand Down
1 change: 1 addition & 0 deletions Zend/zend_vm_def.h
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Expand Up @@ -7680,6 +7680,7 @@ ZEND_VM_COLD_CONST_HANDLER(169, ZEND_COALESCE, CONST|TMP|VAR|CV, JMP_ADDR)
efree_size(ref, sizeof(zend_reference));
}
}
ZVAL_UNDEF(EX_VAR(opline->result.var));
ZEND_VM_NEXT_OPCODE();
}

Expand Down
4 changes: 4 additions & 0 deletions Zend/zend_vm_execute.h
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16 changes: 8 additions & 8 deletions ext/opcache/tests/match/001.phpt
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Expand Up @@ -27,26 +27,26 @@ foreach (range('a', 'i') as $char) {
?>
--EXPECTF--
$_main:
; (lines=15, args=0, vars=1, tmps=2)
; (lines=15, args=0, vars=1, tmps=3)
; (after optimizer)
; %s
0000 INIT_FCALL 2 %d string("range")
0001 SEND_VAL string("a") 1
0002 SEND_VAL string("i") 2
0003 V2 = DO_ICALL
0004 V1 = FE_RESET_R V2 0013
0005 FE_FETCH_R V1 CV0($char) 0013
0003 V1 = DO_ICALL
0004 V2 = FE_RESET_R V1 0013
0005 FE_FETCH_R V2 CV0($char) 0013
0006 INIT_FCALL 1 %d string("var_dump")
0007 INIT_FCALL 1 %d string("test")
0008 SEND_VAR CV0($char) 1
0009 V2 = DO_UCALL
0010 SEND_VAR V2 1
0009 V3 = DO_UCALL
0010 SEND_VAR V3 1
0011 DO_ICALL
0012 JMP 0005
0013 FE_FREE V1
0013 FE_FREE V2
0014 RETURN int(1)
LIVE RANGES:
1: 0005 - 0013 (loop)
2: 0005 - 0013 (loop)

test:
; (lines=9, args=1, vars=1, tmps=0)
Expand Down
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