Initial integration of Sparse Conditional Constant Propagation (SCCP), originally developed in https://github.com/nikic/php-src/tree/opt, into DFA optimization pass.

Author: dstogov

Zend/zend_bitset.h

@@ -245,6 +245,14 @@ static inline int zend_bitset_last(zend_bitset set, uint32_t len)
 	} \
 } while (0)
 
+static inline int zend_bitset_pop_first(zend_bitset set, uint32_t len) {
+	int i = zend_bitset_first(set, len);
+	if (i >= 0) {
+		zend_bitset_excl(set, i);
+	}
+	return i;
+}
+
 #endif /* _ZEND_BITSET_H_ */
 
 /*

ext/opcache/Optimizer/dfa_pass.c

@@ -319,7 +319,7 @@ static zend_bool opline_supports_assign_contraction(
 	return 1;
 }
 
-void zend_dfa_optimize_op_array(zend_op_array *op_array, zend_optimizer_ctx *ctx, zend_ssa *ssa)
+void zend_dfa_optimize_op_array(zend_op_array *op_array, zend_optimizer_ctx *ctx, zend_ssa *ssa, zend_call_info **call_map)
 {
 	if (ctx->debug_level & ZEND_DUMP_BEFORE_DFA_PASS) {
 		zend_dump_op_array(op_array, ZEND_DUMP_SSA, "before dfa pass", ssa);
@@ -332,6 +332,8 @@ void zend_dfa_optimize_op_array(zend_op_array *op_array, zend_optimizer_ctx *ctx
 		zend_op *opline;
 		zval tmp;
 
+		sccp_optimize_op_array(op_array, ssa, call_map);
+
 		for (v = op_array->last_var; v < ssa->vars_count; v++) {
 
 			op_1 = ssa->vars[v].definition;
@@ -598,7 +600,7 @@ void zend_optimize_dfa(zend_op_array *op_array, zend_optimizer_ctx *ctx)
 		return;
 	}
 
-	zend_dfa_optimize_op_array(op_array, ctx, &ssa);
+	zend_dfa_optimize_op_array(op_array, ctx, &ssa, NULL);
 
 	/* Destroy SSA */
 	zend_arena_release(&ctx->arena, checkpoint);