Revert "Revert "JIT build fix""

This reverts commit 4e2f958.

Author: nielsdos

Zend/Optimizer/dfa_pass.c

@@ -466,10 +466,7 @@ int zend_dfa_optimize_calls(zend_op_array *op_array, zend_ssa *ssa)
 							int var_num = ssa_op->op1_use;
 							zend_ssa_var *var = ssa->vars + var_num;
 
-							if (ssa_op->op1_def >= 0) {
-								zend_ssa_replace_op1_def_op1_use(ssa, ssa_op);
-							}
-
+							ZEND_ASSERT(ssa_op->op1_def < 0);
 							zend_ssa_unlink_use_chain(ssa, op_num, ssa_op->op1_use);
 							ssa_op->op1_use = -1;
 							ssa_op->op1_use_chain = -1;
@@ -1069,49 +1066,73 @@ static bool zend_dfa_try_to_replace_result(zend_op_array *op_array, zend_ssa *ss
 	return 0;
 }
 
+static bool op_dominates(const zend_op_array *op_array, const zend_ssa *ssa, const zend_op *a, const zend_op *b)
+{
+	uint32_t a_block = ssa->cfg.map[a - op_array->opcodes];
+	uint32_t b_block = ssa->cfg.map[b - op_array->opcodes];
+	if (a_block == b_block) {
+		return a < b;
+	} else {
+		return dominates(ssa->cfg.blocks, a_block, b_block);
+	}
+}
+
+static bool op_dominates_all_uses(const zend_op_array *op_array, const zend_ssa *ssa, int start) {
+	int use;
+	FOREACH_USE(ssa->vars + ssa->ops[start].op1_def, use) {
+		if (!op_dominates(op_array, ssa, op_array->opcodes + start, op_array->opcodes + use)) {
+			return false;
+		}
+	} FOREACH_USE_END();
+	return true;
+}
+
 /* Sets a flag on SEND ops when a copy can be a avoided. */
-static void zend_dfa_optimize_send_copies(zend_op_array *op_array, zend_ssa *ssa)
+static void zend_dfa_optimize_send_copies(zend_op_array *op_array, const zend_ssa *ssa)
 {
-	/* func_get_args() and indirect accesses could make the optimization observable */
-	if (ssa->cfg.flags & (ZEND_FUNC_VARARG | ZEND_FUNC_INDIRECT_VAR_ACCESS)) {
+	/* func_get_args() etc could make the optimization observable */
+	if (ssa->cfg.flags & ZEND_FUNC_VARARG) {
 		return;
 	}
 
 	for (uint32_t i = 0; i < op_array->last; i++) {
-		zend_op *opline = op_array->opcodes + i;
+		const zend_op *opline = &op_array->opcodes[i];
 		if ((opline->opcode != ZEND_SEND_VAR && opline->opcode != ZEND_SEND_VAR_EX) || opline->op2_type != IS_UNUSED || opline->op1_type != IS_CV) {
 			continue;
 		}
-
-		zend_ssa_op *ssa_op = ssa->ops + i;
-		int op1_def = ssa_op->op1_def;
-		if (op1_def == -1) {
-			continue;
-		}
-
-		int ssa_cv = ssa_op->op1_use;
-
 #if 0
-		/* Argument move must not be observable in backtraces */
+		/* NULL must not be visible in backtraces */
+		int ssa_cv = ssa->ops[i].op1_use;
 		if (ssa->vars[ssa_cv].var < op_array->num_args) {
 			continue;
 		}
 #endif
-
 		/* Unsetting a CV is always fine if it gets overwritten afterwards.
 		 * Since type inference often infers very wide types, we are very loose in matching types. */
 		uint32_t type = ssa->var_info[ssa_cv].type;
 		if ((type & (MAY_BE_REF|MAY_BE_UNDEF)) || !(type & MAY_BE_RC1) || !(type & (MAY_BE_STRING|MAY_BE_ARRAY))) {
 			continue;
 		}
 
-		zend_ssa_var *ssa_var = ssa->vars + op1_def;
-
-		if (ssa_var->no_val && !ssa_var->alias) {
-			/* Flag will be used by VM type spec handler */
-			opline->extended_value = 1;
-		} else if (opline->opcode == ZEND_SEND_VAR) {
-			zend_ssa_replace_op1_def_op1_use(ssa, ssa_op);
+		if (opline->opcode == ZEND_SEND_VAR) {
+			/* Check if the call dominates the assignment and the assignment dominates all the future uses of this SSA variable */
+			int next_use = ssa->ops[i].op1_use_chain;
+			if (next_use >= 0
+				&& op_array->opcodes[next_use].opcode == ZEND_ASSIGN
+				&& ssa->ops[next_use].op1_use == ssa_cv
+				&& ssa->ops[next_use].op2_use >= 0
+				&& op_dominates(op_array, ssa, opline, op_array->opcodes + next_use)) {
+				if (op_dominates_all_uses(op_array, ssa, next_use)) {
+					op_array->opcodes[i].extended_value = 1;
+					//fprintf(stderr, "yes optimize 1\n");
+				}
+			}
+		} else /* ZEND_SEND_VAR_EX */ {
+			ZEND_ASSERT(ssa->ops[i].op1_def != -1);
+			if (ssa->vars[ssa->ops[i].op1_def].no_val) {
+				op_array->opcodes[i].extended_value = 1;
+				//fprintf(stderr, "yes optimize 2\n");
+			}
 		}
 	}
 }
@@ -1134,14 +1155,6 @@ void zend_dfa_optimize_op_array(zend_op_array *op_array, zend_optimizer_ctx *ctx
 		ssa_verify_integrity(op_array, ssa, "before dfa");
 #endif
 
-		/* Optimization should not be done on main because of globals. */
-		if (op_array->function_name) {
-			zend_dfa_optimize_send_copies(op_array, ssa);
-#if ZEND_DEBUG_DFA
-			ssa_verify_integrity(op_array, ssa, "after optimize send copies");
-#endif
-		}
-
 		if (ZEND_OPTIMIZER_PASS_8 & ctx->optimization_level) {
 			if (sccp_optimize_op_array(ctx, op_array, ssa, call_map)) {
 				remove_nops = 1;
@@ -1182,6 +1195,11 @@ void zend_dfa_optimize_op_array(zend_op_array *op_array, zend_optimizer_ctx *ctx
 #endif
 		}
 
+		/* Optimization should not be done on main because of globals. */
+		if (op_array->function_name) {
+			zend_dfa_optimize_send_copies(op_array, ssa);
+		}
+
 		for (v = op_array->last_var; v < ssa->vars_count; v++) {
 
 			op_1 = ssa->vars[v].definition;

Zend/Optimizer/sccp.c

@@ -98,7 +98,7 @@ typedef struct _sccp_ctx {
 #define MAKE_TOP(zv) (Z_TYPE_INFO_P(zv) = TOP)
 #define MAKE_BOT(zv) (Z_TYPE_INFO_P(zv) = BOT)
 
-static void scp_dump_value(const zval *zv) {
+static void scp_dump_value(zval *zv) {
 	if (IS_TOP(zv)) {
 		fprintf(stderr, " top");
 	} else if (IS_BOT(zv)) {
@@ -245,8 +245,6 @@ static bool can_replace_op1(
 		case ZEND_SEND_USER:
 		case ZEND_FE_RESET_RW:
 			return 0;
-		case ZEND_SEND_VAR:
-			return ssa_op->op1_def == -1;
 		/* Do not accept CONST */
 		case ZEND_ROPE_ADD:
 		case ZEND_ROPE_END:
@@ -1052,12 +1050,6 @@ static void sccp_visit_instr(scdf_ctx *scdf, zend_op *opline, zend_ssa_op *ssa_o
 		case ZEND_SEND_VAL:
 		case ZEND_SEND_VAR:
 		{
-			if (opline->opcode == ZEND_SEND_VAR) {
-				/* TODO ? */
-				/* Can be UNDEF or a value copy */
-				SET_RESULT_BOT(op1);
-			}
-
 			/* If the value of a SEND for an ICALL changes, we need to reconsider the
 			 * ICALL result value. Otherwise we can ignore the opcode. */
 			zend_call_info *call;
@@ -2042,14 +2034,8 @@ static int remove_call(sccp_ctx *ctx, zend_op *opline, zend_ssa_op *ssa_op)
 		&ssa->ops[call->caller_init_opline - op_array->opcodes]);
 
 	for (i = 0; i < call->num_args; i++) {
-		zend_op *op = call->arg_info[i].opline;
-		zend_ssa_op *this_ssa_op = &ssa->ops[op - op_array->opcodes];
-
-		if (op->opcode == ZEND_SEND_VAR && this_ssa_op->op1_def >= 0) {
-			zend_ssa_replace_op1_def_op1_use(ssa, this_ssa_op);
-		}
-
-		zend_ssa_remove_instr(ssa, op, this_ssa_op);
+		zend_ssa_remove_instr(ssa, call->arg_info[i].opline,
+			&ssa->ops[call->arg_info[i].opline - op_array->opcodes]);
 	}
 
 	// TODO: remove call_info completely???

Zend/Optimizer/zend_cfg.c

@@ -761,7 +761,7 @@ ZEND_API void zend_cfg_compute_dominators_tree(const zend_op_array *op_array, ze
 }
 /* }}} */
 
-static bool dominates(zend_basic_block *blocks, int a, int b) /* {{{ */
+bool dominates(const zend_basic_block *blocks, int a, int b) /* {{{ */
 {
 	while (blocks[b].level > blocks[a].level) {
 		b = blocks[b].idom;

Zend/Optimizer/zend_cfg.h

@@ -120,6 +120,7 @@ void zend_cfg_remark_reachable_blocks(const zend_op_array *op_array, zend_cfg *c
 ZEND_API void zend_cfg_build_predecessors(zend_arena **arena, zend_cfg *cfg);
 ZEND_API void zend_cfg_compute_dominators_tree(const zend_op_array *op_array, zend_cfg *cfg);
 ZEND_API void zend_cfg_identify_loops(const zend_op_array *op_array, zend_cfg *cfg);
+bool dominates(const zend_basic_block *blocks, int a, int b);
 
 END_EXTERN_C()
 

Zend/Optimizer/zend_dfg.c

@@ -152,7 +152,6 @@ static zend_always_inline void _zend_dfg_add_use_def_op(const zend_op_array *op_
 		case ZEND_BIND_STATIC:
 		case ZEND_SEND_VAR_NO_REF:
 		case ZEND_SEND_VAR_NO_REF_EX:
-		case ZEND_SEND_VAR:
 		case ZEND_SEND_VAR_EX:
 		case ZEND_SEND_FUNC_ARG:
 		case ZEND_SEND_REF:
@@ -174,6 +173,7 @@ static zend_always_inline void _zend_dfg_add_use_def_op(const zend_op_array *op_
 				goto add_op1_def;
 			}
 			break;
+		case ZEND_SEND_VAR:
 		case ZEND_CAST:
 		case ZEND_QM_ASSIGN:
 		case ZEND_JMP_SET:

Zend/Optimizer/zend_inference.c

@@ -2950,9 +2950,6 @@ static zend_always_inline zend_result _zend_update_type_info(
 				if (t1 & (MAY_BE_RC1|MAY_BE_REF)) {
 					tmp |= MAY_BE_RCN;
 				}
-				if ((t1 & (MAY_BE_ARRAY|MAY_BE_STRING)) && (t1 & MAY_BE_RC1) && !(t1 & (MAY_BE_UNDEF|MAY_BE_REF)) && ssa_vars[ssa_op->op1_def].no_val && !ssa_vars[ssa_op->op1_def].alias) {
-					tmp |= MAY_BE_UNDEF;
-				}
 				UPDATE_SSA_TYPE(tmp, ssa_op->op1_def);
 				COPY_SSA_OBJ_TYPE(ssa_op->op1_use, ssa_op->op1_def);
 			}
@@ -2994,9 +2991,6 @@ static zend_always_inline zend_result _zend_update_type_info(
 		case ZEND_SEND_FUNC_ARG:
 			if (ssa_op->op1_def >= 0) {
 				tmp = (t1 & MAY_BE_UNDEF)|MAY_BE_REF|MAY_BE_RC1|MAY_BE_RCN|MAY_BE_ANY|MAY_BE_ARRAY_KEY_ANY|MAY_BE_ARRAY_OF_ANY|MAY_BE_ARRAY_OF_REF;
-				if (opline->opcode == ZEND_SEND_VAR_EX && (t1 & (MAY_BE_ARRAY|MAY_BE_STRING)) && (t1 & MAY_BE_RC1) && !(t1 & (MAY_BE_UNDEF|MAY_BE_REF)) && ssa_vars[ssa_op->op1_def].no_val && !ssa_vars[ssa_op->op1_def].alias) {
-					tmp |= MAY_BE_UNDEF;
-				}
 				UPDATE_SSA_TYPE(tmp, ssa_op->op1_def);
 			}
 			break;

Zend/Optimizer/zend_ssa.c

@@ -18,19 +18,13 @@
 */
 
 #include "zend_compile.h"
+#include "zend_cfg.h"
 #include "zend_dfg.h"
 #include "zend_ssa.h"
 #include "zend_dump.h"
 #include "zend_inference.h"
 #include "Optimizer/zend_optimizer_internal.h"
 
-static bool dominates(const zend_basic_block *blocks, int a, int b) {
-	while (blocks[b].level > blocks[a].level) {
-		b = blocks[b].idom;
-	}
-	return a == b;
-}
-
 static bool will_rejoin(
 		const zend_cfg *cfg, const zend_dfg *dfg, const zend_basic_block *block,
 		int other_successor, int exclude, int var) {
@@ -682,7 +676,6 @@ static zend_always_inline int _zend_ssa_rename_op(const zend_op_array *op_array,
 		case ZEND_SEND_VAR_NO_REF:
 		case ZEND_SEND_VAR_NO_REF_EX:
 		case ZEND_SEND_VAR_EX:
-		case ZEND_SEND_VAR:
 		case ZEND_SEND_FUNC_ARG:
 		case ZEND_SEND_REF:
 		case ZEND_SEND_UNPACK:
@@ -703,6 +696,7 @@ static zend_always_inline int _zend_ssa_rename_op(const zend_op_array *op_array,
 				goto add_op1_def;
 			}
 			break;
+		case ZEND_SEND_VAR:
 		case ZEND_CAST:
 		case ZEND_QM_ASSIGN:
 		case ZEND_JMP_SET:
@@ -1680,13 +1674,3 @@ void zend_ssa_rename_var_uses(zend_ssa *ssa, int old, int new, bool update_types
 	old_var->phi_use_chain = NULL;
 }
 /* }}} */
-
-void zend_ssa_replace_op1_def_op1_use(zend_ssa *ssa, zend_ssa_op *ssa_op)
-{
-	int op1_new = ssa_op->op1_use;
-	ZEND_ASSERT(op1_new >= 0);
-	ZEND_ASSERT(ssa_op->op1_def >= 0);
-	/* zend_ssa_rename_var_uses() clear use_chain & phi_use_chain for us */
-	zend_ssa_rename_var_uses(ssa, ssa_op->op1_def, op1_new, true);
-	zend_ssa_remove_op1_def(ssa, ssa_op);
-}

Zend/Optimizer/zend_ssa.h

@@ -159,7 +159,6 @@ void zend_ssa_remove_uses_of_var(zend_ssa *ssa, int var_num);
 void zend_ssa_remove_block(zend_op_array *op_array, zend_ssa *ssa, int b);
 void zend_ssa_rename_var_uses(zend_ssa *ssa, int old_var, int new_var, bool update_types);
 void zend_ssa_remove_block_from_cfg(zend_ssa *ssa, int b);
-void zend_ssa_replace_op1_def_op1_use(zend_ssa *ssa, zend_ssa_op *ssa_op);
 
 static zend_always_inline void _zend_ssa_remove_def(zend_ssa_var *var)
 {

ext/opcache/jit/zend_jit.c

@@ -156,7 +156,7 @@ static int zend_jit_assign_to_variable(dasm_State    **Dst,
                                        zend_jit_addr   res_addr,
                                        bool       check_exception);
 
-static bool dominates(const zend_basic_block *blocks, int a, int b) {
+bool dominates(const zend_basic_block *blocks, int a, int b) {
 	while (blocks[b].level > blocks[a].level) {
 		b = blocks[b].idom;
 	}