JIT: Fixed wrong comparison skip

Author: dstogov

ext/opcache/jit/zend_jit_trace.c

@@ -3433,7 +3433,7 @@ static void zend_jit_trace_update_condition_ranges(const zend_op *opline, const
 	}
 }
 
-static zend_bool zend_jit_may_skip_comparison(const zend_op *opline, const zend_ssa_op *ssa_op, const zend_ssa *ssa, const zend_op **ssa_opcodes)
+static zend_bool zend_jit_may_skip_comparison(const zend_op *opline, const zend_ssa_op *ssa_op, const zend_ssa *ssa, const zend_op **ssa_opcodes, const zend_op_array *op_array)
 {
 	zend_uchar prev_opcode;
 
@@ -3442,18 +3442,23 @@ static zend_bool zend_jit_may_skip_comparison(const zend_op *opline, const zend_
 	 && Z_LVAL_P(RT_CONSTANT(opline, opline->op1)) == 0) {
 		if (ssa_op->op2_use >= 0) {
 			if ((ssa_op-1)->op1_def == ssa_op->op2_use) {
-				prev_opcode = ssa_opcodes[(ssa_op - ssa->ops) - 1]->opcode;
+				ssa_op--;
+				opline = ssa_opcodes[ssa_op - ssa->ops];
+				prev_opcode = opline->opcode;
 				if (prev_opcode == ZEND_PRE_INC
 				 || prev_opcode == ZEND_PRE_DEC
 				 || prev_opcode == ZEND_POST_INC
 				 || prev_opcode == ZEND_POST_DEC) {
-					return 1;
+					return (OP1_INFO() & ((MAY_BE_UNDEF|MAY_BE_ANY|MAY_BE_REF)-MAY_BE_LONG)) == 0;
 				}
 			} else if ((ssa_op-1)->result_def == ssa_op->op2_use) {
-				prev_opcode = ssa_opcodes[(ssa_op - ssa->ops) - 1]->opcode;
+				ssa_op--;
+				opline = ssa_opcodes[ssa_op - ssa->ops];
+				prev_opcode = opline->opcode;
 				if (prev_opcode == ZEND_ADD
 				 || prev_opcode == ZEND_SUB) {
-					return 1;
+					return (OP1_INFO() & ((MAY_BE_UNDEF|MAY_BE_ANY|MAY_BE_REF)-MAY_BE_LONG)) == 0 &&
+						(OP2_INFO() & ((MAY_BE_UNDEF|MAY_BE_ANY|MAY_BE_REF)-MAY_BE_LONG)) == 0;
 				}
 			}
 		}
@@ -3462,18 +3467,23 @@ static zend_bool zend_jit_may_skip_comparison(const zend_op *opline, const zend_
 	 && Z_LVAL_P(RT_CONSTANT(opline, opline->op2)) == 0) {
 		if (ssa_op->op1_use >= 0) {
 			if ((ssa_op-1)->op1_def == ssa_op->op1_use) {
-				prev_opcode = ssa_opcodes[(ssa_op - ssa->ops) - 1]->opcode;
+				ssa_op--;
+				opline = ssa_opcodes[ssa_op - ssa->ops];
+				prev_opcode = opline->opcode;
 				if (prev_opcode == ZEND_PRE_INC
 				 || prev_opcode == ZEND_PRE_DEC
 				 || prev_opcode == ZEND_POST_INC
 				 || prev_opcode == ZEND_POST_DEC) {
-					return 1;
+					return (OP1_INFO() & ((MAY_BE_UNDEF|MAY_BE_ANY|MAY_BE_REF)-MAY_BE_LONG)) == 0;
 				}
 			} else if ((ssa_op-1)->result_def == ssa_op->op1_use) {
-				prev_opcode = ssa_opcodes[(ssa_op - ssa->ops) - 1]->opcode;
+				ssa_op--;
+				opline = ssa_opcodes[ssa_op - ssa->ops];
+				prev_opcode = opline->opcode;
 				if (prev_opcode == ZEND_ADD
 				 || prev_opcode == ZEND_SUB) {
-					return 1;
+					return (OP1_INFO() & ((MAY_BE_UNDEF|MAY_BE_ANY|MAY_BE_REF)-MAY_BE_LONG)) == 0 &&
+						(OP2_INFO() & ((MAY_BE_UNDEF|MAY_BE_ANY|MAY_BE_REF)-MAY_BE_LONG)) == 0;
 				}
 			}
 		}
@@ -4777,9 +4787,9 @@ static const void *zend_jit_trace(zend_jit_trace_rec *trace_buffer, uint32_t par
 						op2_info = OP2_INFO();
 						skip_comparison =
 							ssa_op != ssa->ops &&
-							(op1_info & (MAY_BE_ANY|MAY_BE_UNDEF)) == MAY_BE_LONG &&
-							(op2_info & (MAY_BE_ANY|MAY_BE_UNDEF)) == MAY_BE_LONG &&
-							zend_jit_may_skip_comparison(opline, ssa_op, ssa, ssa_opcodes);
+							(op1_info & (MAY_BE_ANY|MAY_BE_UNDEF|MAY_BE_GUARD)) == MAY_BE_LONG &&
+							(op2_info & (MAY_BE_ANY|MAY_BE_UNDEF|MAY_BE_GUARD)) == MAY_BE_LONG &&
+							zend_jit_may_skip_comparison(opline, ssa_op, ssa, ssa_opcodes, op_array);
 						CHECK_OP1_TRACE_TYPE();
 						CHECK_OP2_TRACE_TYPE();
 						if ((opline->result_type & (IS_SMART_BRANCH_JMPZ|IS_SMART_BRANCH_JMPNZ)) != 0) {
@@ -4825,9 +4835,9 @@ static const void *zend_jit_trace(zend_jit_trace_rec *trace_buffer, uint32_t par
 						op2_info = OP2_INFO();
 						skip_comparison =
 							ssa_op != ssa->ops &&
-							(op1_info & (MAY_BE_ANY|MAY_BE_UNDEF)) == MAY_BE_LONG &&
-							(op2_info & (MAY_BE_ANY|MAY_BE_UNDEF)) == MAY_BE_LONG &&
-							zend_jit_may_skip_comparison(opline, ssa_op, ssa, ssa_opcodes);
+							(op1_info & (MAY_BE_ANY|MAY_BE_UNDEF|MAY_BE_GUARD)) == MAY_BE_LONG &&
+							(op2_info & (MAY_BE_ANY|MAY_BE_UNDEF|MAY_BE_GUARD)) == MAY_BE_LONG &&
+							zend_jit_may_skip_comparison(opline, ssa_op, ssa, ssa_opcodes, op_array);
 						CHECK_OP1_TRACE_TYPE();
 						CHECK_OP2_TRACE_TYPE();
 						if ((opline->result_type & (IS_SMART_BRANCH_JMPZ|IS_SMART_BRANCH_JMPNZ)) != 0) {

ext/opcache/tests/jit/cmp_007.phpt

@@ -0,0 +1,23 @@
+--TEST--
+JIT CMP: 007 Wrong comparison skip
+--INI--
+opcache.enable=1
+opcache.enable_cli=1
+opcache.file_update_protection=0
+opcache.jit_buffer_size=1M
+opcache.protect_memory=1
+--FILE--
+<?php
+function test($a) {
+    var_dump(1 - $a != 0);
+}
+for ($i = 0; $i < 5; $i++) {
+	test(null);
+}
+?>
+--EXPECT--
+bool(true)
+bool(true)
+bool(true)
+bool(true)
+bool(true)