Remove NOP instructions, introduced bvy SCCP.

This commit discloses unrelated issue caused ext/soap/tests/bug70211.phpt failure.

ext/opcache/Optimizer/dfa_pass.c

@@ -332,7 +332,9 @@ 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);
+		if (sccp_optimize_op_array(op_array, ssa, call_map)) {
+			remove_nops = 1;
+		}
 
 		for (v = op_array->last_var; v < ssa->vars_count; v++) {
 

ext/opcache/Optimizer/sccp.c

@@ -1209,11 +1209,12 @@ static zval *value_from_type_and_range(sccp_ctx *ctx, int var_num, zval *tmp) {
 /* This will try to replace uses of SSA variables we have determined to be constant. Not all uses
  * can be replaced, because some instructions don't accept constant operands or only accept them
  * if they have a certain type. */
-static void replace_constant_operands(sccp_ctx *ctx) {
+static int replace_constant_operands(sccp_ctx *ctx) {
 	zend_ssa *ssa = ctx->ssa;
 	zend_op_array *op_array = ctx->op_array;
 	int i;
 	zval tmp;
+	int removed_ops;
 
 	/* We iterate the variables backwards, so we can eliminate sequences like INIT_ROPE
 	 * and INIT_ARRAY. */
@@ -1291,10 +1292,12 @@ static void replace_constant_operands(sccp_ctx *ctx) {
 						zend_ssa_remove_instr(ssa, call->arg_info[i].opline,
 							&ssa->ops[call->arg_info[i].opline - op_array->opcodes]);
 					}
+					removed_ops = call->num_args + 2;
 				} else {
 					/* Ordinary computational instruction -> remove it */
 					zend_ssa_remove_result_def(ssa, ssa_op);
 					zend_ssa_remove_instr(ssa, opline, ssa_op);
+					removed_ops++;
 				}
 			} else if (ssa_op->op1_def == i) {
 				/* Compound assign or incdec -> convert to direct ASSIGN */
@@ -1318,6 +1321,7 @@ static void replace_constant_operands(sccp_ctx *ctx) {
 
 				/* Remove OP_DATA opcode */
 				if (opline->opcode == ZEND_ASSIGN_DIM) {
+					removed_ops++;
 					zend_ssa_remove_instr(ssa, opline + 1, ssa_op + 1);
 				}
 
@@ -1334,6 +1338,8 @@ static void replace_constant_operands(sccp_ctx *ctx) {
 			zend_ssa_remove_phi(ssa, var->definition_phi);
 		}*/
 	}
+
+	return removed_ops;
 }
 
 static void sccp_context_init(sccp_ctx *ctx,
@@ -1370,10 +1376,11 @@ static void sccp_context_free(sccp_ctx *ctx) {
 	efree(ctx->values);
 }
 
-void sccp_optimize_op_array(zend_op_array *op_array, zend_ssa *ssa, zend_call_info **call_map)
+int sccp_optimize_op_array(zend_op_array *op_array, zend_ssa *ssa, zend_call_info **call_map)
 {
 	scdf_ctx scdf;
 	sccp_ctx ctx;
+	int removed_ops = 0;
 
 	sccp_context_init(&ctx, ssa, op_array, call_map);
 
@@ -1384,9 +1391,11 @@ void sccp_optimize_op_array(zend_op_array *op_array, zend_ssa *ssa, zend_call_in
 	scdf_init(&scdf, op_array, ssa, &ctx);
 	scdf_solve(&scdf, "SCCP");
 
-	scdf_remove_unreachable_blocks(&scdf);
+	removed_ops += scdf_remove_unreachable_blocks(&scdf);
-	replace_constant_operands(&ctx);
+	removed_ops += replace_constant_operands(&ctx);
 
 	scdf_free(&scdf);
 	sccp_context_free(&ctx);
+
+	return removed_ops;
 }

ext/opcache/Optimizer/scdf.c

@@ -216,14 +216,18 @@ static zend_bool kept_alive_by_live_range(scdf_ctx *scdf, uint32_t block) {
 /* Removes unreachable blocks. This will remove both the instructions (and phis) in the
  * blocks, as well as remove them from the successor / predecessor lists and mark them
  * unreachable. Blocks already marked unreachable are not removed. */
-void scdf_remove_unreachable_blocks(scdf_ctx *scdf) {
+int scdf_remove_unreachable_blocks(scdf_ctx *scdf) {
 	zend_ssa *ssa = scdf->ssa;
 	int i;
+	int removed_ops = 0;
+
 	for (i = 0; i < ssa->cfg.blocks_count; i++) {
 		if (!zend_bitset_in(scdf->executable_blocks, i)
 				&& (ssa->cfg.blocks[i].flags & ZEND_BB_REACHABLE)
 				&& !kept_alive_by_live_range(scdf, i)) {
+			removed_ops += ssa->cfg.blocks[i].len;
 			zend_ssa_remove_block(scdf->op_array, ssa, i);
 		}
 	}
+	return removed_ops;
 }

ext/opcache/Optimizer/scdf.h

@@ -51,7 +51,7 @@ void scdf_init(scdf_ctx *scdf, zend_op_array *op_array, zend_ssa *ssa, void *ctx
 void scdf_solve(scdf_ctx *scdf, const char *name);
 void scdf_free(scdf_ctx *scdf);
 
-void scdf_remove_unreachable_blocks(scdf_ctx *scdf);
+int scdf_remove_unreachable_blocks(scdf_ctx *scdf);
 
 /* Add uses to worklist */
 static inline void scdf_add_to_worklist(scdf_ctx *scdf, int var_num) {

ext/opcache/Optimizer/zend_optimizer_internal.h

@@ -110,6 +110,6 @@ uint32_t zend_optimizer_classify_function(zend_string *name, uint32_t num_args);
 void zend_optimizer_migrate_jump(zend_op_array *op_array, zend_op *new_opline, zend_op *opline);
 void zend_optimizer_shift_jump(zend_op_array *op_array, zend_op *opline, uint32_t *shiftlist);
 zend_uchar zend_compound_assign_to_binary_op(zend_uchar opcode);
-void sccp_optimize_op_array(zend_op_array *op_arrya, zend_ssa *ssa, zend_call_info **call_map);
+int sccp_optimize_op_array(zend_op_array *op_arrya, zend_ssa *ssa, zend_call_info **call_map);
 
 #endif