From: Dmitry Stogov <dmitry@zend.com>
Date: Thu, 27 Aug 2020 12:29:11 +0000 (+0300)
Subject: Update operands range information accoring to the taken branches and use this indorma... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e701146070e3287dc4519f543b2228ca54f4f029;p=php

Update operands range information accoring to the taken branches and use this indormation to eliminate useless overflow checks.
---

diff --git a/ext/opcache/jit/zend_jit.c b/ext/opcache/jit/zend_jit.c
index 5d1b2414a8..5254a39518 100644
--- a/ext/opcache/jit/zend_jit.c
+++ b/ext/opcache/jit/zend_jit.c
@@ -111,7 +111,6 @@ static const void *zend_jit_func_trace_counter_handler = NULL;
 static const void *zend_jit_ret_trace_counter_handler = NULL;
 static const void *zend_jit_loop_trace_counter_handler = NULL;
 
-static int zend_may_overflow(const zend_op *opline, const zend_op_array *op_array, zend_ssa *ssa);
 static void ZEND_FASTCALL zend_runtime_jit(void);
 
 static int zend_jit_trace_op_len(const zend_op *opline);
@@ -487,9 +486,10 @@ static void *dasm_link_and_encode(dasm_State             **dasm_state,
 	return entry;
 }
 
-static int zend_may_overflow_ex(const zend_op *opline, const zend_ssa_op *ssa_op, const zend_op_array *op_array, zend_ssa *ssa)
+static int zend_may_overflow(const zend_op *opline, const zend_ssa_op *ssa_op, const zend_op_array *op_array, zend_ssa *ssa)
 {
 	int res;
+	zend_long op1_min, op1_max, op2_min, op2_max;
 
 	if (!ssa->ops || !ssa->var_info) {
 		return 1;
@@ -498,24 +498,38 @@ static int zend_may_overflow_ex(const zend_op *opline, const zend_ssa_op *ssa_op
 		case ZEND_PRE_INC:
 		case ZEND_POST_INC:
 			res = ssa_op->op1_def;
-			return (res < 0 ||
-				!ssa->var_info[res].has_range ||
-				ssa->var_info[res].range.overflow);
+			if (res < 0
+			 || !ssa->var_info[res].has_range
+			 || ssa->var_info[res].range.overflow) {
+				if (!OP1_HAS_RANGE()) {
+					return 1;
+				}
+				op1_max = OP1_MAX_RANGE();
+				if (op1_max == ZEND_LONG_MAX) {
+					return 1;
+				}
+			}
+			return 0;
 		case ZEND_PRE_DEC:
 		case ZEND_POST_DEC:
 			res = ssa_op->op1_def;
-			return (res < 0 ||
-				!ssa->var_info[res].has_range ||
-				ssa->var_info[res].range.underflow);
+			if (res < 0
+			 || !ssa->var_info[res].has_range
+			 || ssa->var_info[res].range.underflow) {
+				if (!OP1_HAS_RANGE()) {
+					return 1;
+				}
+				op1_min = OP1_MIN_RANGE();
+				if (op1_min == ZEND_LONG_MIN) {
+					return 1;
+				}
+			}
+			return 0;
 		case ZEND_ADD:
 			res = ssa_op->result_def;
-			if (res < 0 ||
-			    !ssa->var_info[res].has_range) {
-				return 1;
-			}
-			if (ssa->var_info[res].range.underflow) {
-				zend_long op1_min, op2_min;
-
+			if (res < 0
+			 || !ssa->var_info[res].has_range
+			 || ssa->var_info[res].range.underflow) {
 				if (!OP1_HAS_RANGE() || !OP2_HAS_RANGE()) {
 					return 1;
 				}
@@ -525,9 +539,9 @@ static int zend_may_overflow_ex(const zend_op *opline, const zend_ssa_op *ssa_op
 					return 1;
 				}
 			}
-			if (ssa->var_info[res].range.overflow) {
-				zend_long op1_max, op2_max;
-
+			if (res < 0
+			 || !ssa->var_info[res].has_range
+			 || ssa->var_info[res].range.overflow) {
 				if (!OP1_HAS_RANGE() || !OP2_HAS_RANGE()) {
 					return 1;
 				}
@@ -540,13 +554,9 @@ static int zend_may_overflow_ex(const zend_op *opline, const zend_ssa_op *ssa_op
 			return 0;
 		case ZEND_SUB:
 			res = ssa_op->result_def;
-			if (res < 0 ||
-			    !ssa->var_info[res].has_range) {
-				return 1;
-			}
-			if (ssa->var_info[res].range.underflow) {
-				zend_long op1_min, op2_max;
-
+			if (res < 0
+			 || !ssa->var_info[res].has_range
+			 || ssa->var_info[res].range.underflow) {
 				if (!OP1_HAS_RANGE() || !OP2_HAS_RANGE()) {
 					return 1;
 				}
@@ -556,9 +566,9 @@ static int zend_may_overflow_ex(const zend_op *opline, const zend_ssa_op *ssa_op
 					return 1;
 				}
 			}
-			if (ssa->var_info[res].range.overflow) {
-				zend_long op1_max, op2_min;
-
+			if (res < 0
+			 || !ssa->var_info[res].has_range
+			 || ssa->var_info[res].range.overflow) {
 				if (!OP1_HAS_RANGE() || !OP2_HAS_RANGE()) {
 					return 1;
 				}
@@ -578,13 +588,9 @@ static int zend_may_overflow_ex(const zend_op *opline, const zend_ssa_op *ssa_op
 		case ZEND_ASSIGN_OP:
 			if (opline->extended_value == ZEND_ADD) {
 				res = ssa_op->op1_def;
-				if (res < 0 ||
-				    !ssa->var_info[res].has_range) {
-					return 1;
-				}
-				if (ssa->var_info[res].range.underflow) {
-					zend_long op1_min, op2_min;
-
+				if (res < 0
+				 || !ssa->var_info[res].has_range
+				 || ssa->var_info[res].range.underflow) {
 					if (!OP1_HAS_RANGE() || !OP2_HAS_RANGE()) {
 						return 1;
 					}
@@ -594,9 +600,9 @@ static int zend_may_overflow_ex(const zend_op *opline, const zend_ssa_op *ssa_op
 						return 1;
 					}
 				}
-				if (ssa->var_info[res].range.overflow) {
-					zend_long op1_max, op2_max;
-
+				if (res < 0
+				 || !ssa->var_info[res].has_range
+				 || ssa->var_info[res].range.overflow) {
 					if (!OP1_HAS_RANGE() || !OP2_HAS_RANGE()) {
 						return 1;
 					}
@@ -609,13 +615,9 @@ static int zend_may_overflow_ex(const zend_op *opline, const zend_ssa_op *ssa_op
 				return 0;
 			} else if (opline->extended_value == ZEND_SUB) {
 				res = ssa_op->op1_def;
-				if (res < 0 ||
-				    !ssa->var_info[res].has_range) {
-					return 1;
-				}
-				if (ssa->var_info[res].range.underflow) {
-					zend_long op1_min, op2_max;
-
+				if (res < 0
+				 || !ssa->var_info[res].has_range
+				 || ssa->var_info[res].range.underflow) {
 					if (!OP1_HAS_RANGE() || !OP2_HAS_RANGE()) {
 						return 1;
 					}
@@ -625,9 +627,9 @@ static int zend_may_overflow_ex(const zend_op *opline, const zend_ssa_op *ssa_op
 						return 1;
 					}
 				}
-				if (ssa->var_info[res].range.overflow) {
-					zend_long op1_max, op2_min;
-
+				if (res < 0
+				 || !ssa->var_info[res].has_range
+				 || ssa->var_info[res].range.overflow) {
 					if (!OP1_HAS_RANGE() || !OP2_HAS_RANGE()) {
 						return 1;
 					}
@@ -650,11 +652,6 @@ static int zend_may_overflow_ex(const zend_op *opline, const zend_ssa_op *ssa_op
 	}
 }
 
-static int zend_may_overflow(const zend_op *opline, const zend_op_array *op_array, zend_ssa *ssa)
-{
-	return zend_may_overflow_ex(opline, &ssa->ops[opline - op_array->opcodes], op_array, ssa);
-}
-
 static int zend_jit_build_cfg(const zend_op_array *op_array, zend_cfg *cfg)
 {
 	uint32_t flags;
@@ -2253,7 +2250,7 @@ static int zend_jit(const zend_op_array *op_array, zend_ssa *ssa, const zend_op
 								op1_def_info, OP1_DEF_REG_ADDR(),
 								res_use_info, res_info,
 								res_addr,
-								(op1_info & MAY_BE_LONG) && (op1_def_info & MAY_BE_DOUBLE) && zend_may_overflow(opline, op_array, ssa),
+								(op1_info & MAY_BE_LONG) && (op1_def_info & MAY_BE_DOUBLE) && zend_may_overflow(opline, ssa_op, op_array, ssa),
 								zend_may_throw(opline, ssa_op, op_array, ssa))) {
 							goto jit_failure;
 						}
@@ -2343,7 +2340,7 @@ static int zend_jit(const zend_op_array *op_array, zend_ssa *ssa, const zend_op
 								op2_info, OP2_REG_ADDR(),
 								res_use_info, res_info, res_addr,
 								send_result,
-								(op1_info & MAY_BE_LONG) && (op2_info & MAY_BE_LONG) && (res_info & MAY_BE_DOUBLE) && zend_may_overflow(opline, op_array, ssa),
+								(op1_info & MAY_BE_LONG) && (op2_info & MAY_BE_LONG) && (res_info & MAY_BE_DOUBLE) && zend_may_overflow(opline, ssa_op, op_array, ssa),
 								zend_may_throw(opline, ssa_op, op_array, ssa))) {
 							goto jit_failure;
 						}
@@ -2423,7 +2420,7 @@ static int zend_jit(const zend_op_array *op_array, zend_ssa *ssa, const zend_op
 						if (!zend_jit_assign_op(&dasm_state, opline,
 								op1_info, op1_def_info, OP1_RANGE(),
 								op2_info, OP2_RANGE(),
-								(op1_info & MAY_BE_LONG) && (op2_info & MAY_BE_LONG) && (op1_def_info & MAY_BE_DOUBLE) && zend_may_overflow(opline, op_array, ssa),
+								(op1_info & MAY_BE_LONG) && (op2_info & MAY_BE_LONG) && (op1_def_info & MAY_BE_DOUBLE) && zend_may_overflow(opline, ssa_op, op_array, ssa),
 								zend_may_throw(opline, ssa_op, op_array, ssa))) {
 							goto jit_failure;
 						}
diff --git a/ext/opcache/jit/zend_jit_trace.c b/ext/opcache/jit/zend_jit_trace.c
index 419f4f1459..e549ba7ece 100644
--- a/ext/opcache/jit/zend_jit_trace.c
+++ b/ext/opcache/jit/zend_jit_trace.c
@@ -2906,6 +2906,133 @@ static int zend_jit_trace_deoptimization(dasm_State             **Dst,
 	return 1;
 }
 
+static void zend_jit_trace_set_var_range(zend_ssa_var_info *info, zend_long min, zend_long max)
+{
+	info->has_range = 1;
+	info->range.min = min;
+	info->range.max = max;
+	info->range.underflow = 0;
+	info->range.overflow = 0;
+}
+
+static void zend_jit_trace_update_condition_ranges(const zend_op *opline, const zend_ssa_op *ssa_op, const zend_op_array *op_array, zend_ssa *ssa, zend_bool exit_if_true)
+{
+	zend_long op1_min, op1_max, op2_min, op2_max;
+
+	if ((OP1_INFO() & MAY_BE_ANY) != MAY_BE_LONG
+	 || (OP1_INFO() & MAY_BE_ANY) != MAY_BE_LONG) {
+		return;
+	}
+
+	op1_min = OP1_MIN_RANGE();
+	op1_max = OP1_MAX_RANGE();
+	op2_min = OP2_MIN_RANGE();
+	op2_max = OP2_MAX_RANGE();
+
+	switch (opline->opcode) {
+		case ZEND_IS_EQUAL:
+		case ZEND_CASE:
+		case ZEND_IS_IDENTICAL:
+		case ZEND_CASE_STRICT:
+			if (!exit_if_true) {
+				/* op1 == op2 */
+				if (ssa_op->op1_use >= 0) {
+					zend_jit_trace_set_var_range(
+						&ssa->var_info[ssa_op->op1_use],
+						MAX(op1_min, op2_min),
+						MIN(op1_max, op2_max));
+				}
+				if (ssa_op->op2_use >= 0) {
+					zend_jit_trace_set_var_range(
+						&ssa->var_info[ssa_op->op2_use],
+						MAX(op2_min, op1_min),
+						MIN(op2_max, op1_max));
+				}
+			}
+			break;
+		case ZEND_IS_NOT_EQUAL:
+		case ZEND_IS_NOT_IDENTICAL:
+			if (exit_if_true) {
+				/* op1 == op2 */
+				if (ssa_op->op1_use >= 0) {
+					zend_jit_trace_set_var_range(
+						&ssa->var_info[ssa_op->op1_use],
+						MAX(op1_min, op2_min),
+						MIN(op1_max, op2_max));
+				}
+				if (ssa_op->op2_use >= 0) {
+					zend_jit_trace_set_var_range(
+						&ssa->var_info[ssa_op->op2_use],
+						MAX(op2_min, op1_min),
+						MIN(op2_max, op1_max));
+				}
+			}
+			break;
+		case ZEND_IS_SMALLER_OR_EQUAL:
+			if (!exit_if_true) {
+				/* op1 <= op2 */
+				if (ssa_op->op1_use >= 0) {
+					zend_jit_trace_set_var_range(
+						&ssa->var_info[ssa_op->op1_use],
+						op1_min,
+						MIN(op1_max, op2_max));
+				}
+				if (ssa_op->op2_use >= 0) {
+					zend_jit_trace_set_var_range(
+						&ssa->var_info[ssa_op->op2_use],
+						MAX(op2_min, op1_min),
+						op2_max);
+				}
+			} else {
+				/* op1 > op2 */
+				if (ssa_op->op1_use >= 0) {
+					zend_jit_trace_set_var_range(
+						&ssa->var_info[ssa_op->op1_use],
+						op2_min != ZEND_LONG_MAX ? MAX(op1_min, op2_min + 1) : op1_min,
+						op1_max);
+				}
+				if (ssa_op->op2_use >= 0) {
+					zend_jit_trace_set_var_range(
+						&ssa->var_info[ssa_op->op2_use],
+						op2_min,
+						op2_max != ZEND_LONG_MIN ?MIN(op2_max, op1_max - 1) : op1_max);
+				}
+			}
+			break;
+		case ZEND_IS_SMALLER:
+			if (!exit_if_true) {
+				/* op1 < op2 */
+				if (ssa_op->op1_use >= 0) {
+					zend_jit_trace_set_var_range(
+						&ssa->var_info[ssa_op->op1_use],
+						op1_min,
+						op2_max != ZEND_LONG_MIN ? MIN(op1_max, op2_max - 1) : op1_max);
+				}
+				if (ssa_op->op2_use >= 0) {
+					zend_jit_trace_set_var_range(
+						&ssa->var_info[ssa_op->op2_use],
+						op1_min != ZEND_LONG_MAX ? MAX(op2_min, op1_min + 1) : op2_min,
+						op2_max);
+				}
+			} else {
+				/* op1 >= op2 */
+				if (ssa_op->op1_use >= 0) {
+					zend_jit_trace_set_var_range(
+						&ssa->var_info[ssa_op->op1_use],
+						MAX(op1_min, op2_min),
+						op1_max);
+				}
+				if (ssa_op->op2_use >= 0) {
+					zend_jit_trace_set_var_range(
+						&ssa->var_info[ssa_op->op2_use],
+						op2_min,
+						MIN(op2_max, op1_max));
+				}
+			}
+			break;
+	}
+}
+
 static const void *zend_jit_trace(zend_jit_trace_rec *trace_buffer, uint32_t parent_trace, uint32_t exit_num)
 {
 	const void *handler = NULL;
@@ -3235,7 +3362,7 @@ static const void *zend_jit_trace(zend_jit_trace_rec *trace_buffer, uint32_t par
 								op1_def_info, OP1_DEF_REG_ADDR(),
 								res_use_info, res_info,
 								res_addr,
-								(op1_def_info & (MAY_BE_DOUBLE|MAY_BE_GUARD)) && zend_may_overflow_ex(opline, ssa_op, op_array, ssa),
+								(op1_def_info & (MAY_BE_DOUBLE|MAY_BE_GUARD)) && zend_may_overflow(opline, ssa_op, op_array, ssa),
 								zend_may_throw(opline, ssa_op, op_array, ssa))) {
 							goto jit_failure;
 						}
@@ -3380,7 +3507,7 @@ static const void *zend_jit_trace(zend_jit_trace_rec *trace_buffer, uint32_t par
 								op2_info, OP2_REG_ADDR(),
 								res_use_info, res_info, res_addr,
 								send_result,
-								(op1_info & MAY_BE_LONG) && (op2_info & MAY_BE_LONG) && (res_info & (MAY_BE_DOUBLE|MAY_BE_GUARD)) && zend_may_overflow_ex(opline, ssa_op, op_array, ssa),
+								(op1_info & MAY_BE_LONG) && (op2_info & MAY_BE_LONG) && (res_info & (MAY_BE_DOUBLE|MAY_BE_GUARD)) && zend_may_overflow(opline, ssa_op, op_array, ssa),
 								zend_may_throw(opline, ssa_op, op_array, ssa))) {
 							goto jit_failure;
 						}
@@ -3477,7 +3604,7 @@ static const void *zend_jit_trace(zend_jit_trace_rec *trace_buffer, uint32_t par
 						if (!zend_jit_assign_op(&dasm_state, opline,
 								op1_info, op1_def_info, OP1_RANGE(),
 								op2_info, OP2_RANGE(),
-								(op1_info & MAY_BE_LONG) && (op2_info & MAY_BE_LONG) && (op1_def_info & (MAY_BE_DOUBLE|MAY_BE_GUARD)) && zend_may_overflow_ex(opline, ssa_op, op_array, ssa),
+								(op1_info & MAY_BE_LONG) && (op2_info & MAY_BE_LONG) && (op1_def_info & (MAY_BE_DOUBLE|MAY_BE_GUARD)) && zend_may_overflow(opline, ssa_op, op_array, ssa),
 								zend_may_throw(opline, ssa_op, op_array, ssa))) {
 							goto jit_failure;
 						}
@@ -3775,6 +3902,7 @@ static const void *zend_jit_trace(zend_jit_trace_rec *trace_buffer, uint32_t par
 								goto jit_failure;
 							}
 							smart_branch_opcode = exit_if_true ? ZEND_JMPNZ : ZEND_JMPZ;
+							zend_jit_trace_update_condition_ranges(opline, ssa_op, op_array, ssa, exit_if_true);
 						} else {
 							smart_branch_opcode = 0;
 							exit_addr = NULL;
@@ -3812,6 +3940,7 @@ static const void *zend_jit_trace(zend_jit_trace_rec *trace_buffer, uint32_t par
 								exit_if_true = !exit_if_true;
 							}
 							smart_branch_opcode = exit_if_true ? ZEND_JMPNZ : ZEND_JMPZ;
+							zend_jit_trace_update_condition_ranges(opline, ssa_op, op_array, ssa, exit_if_true);
 						} else {
 							smart_branch_opcode = 0;
 							exit_addr = NULL;