From: Dmitry Stogov <dmitry@zend.com>
Date: Tue, 20 Oct 2020 17:29:33 +0000 (+0300)
Subject: Improve JIT for fetching character form string
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0ac810bbc542aff06db75832a100640a0efb39d4;p=php

Improve JIT for fetching character form string
---

diff --git a/ext/opcache/jit/zend_jit_disasm_x86.c b/ext/opcache/jit/zend_jit_disasm_x86.c
index 730a5d1319..afd830e89f 100644
--- a/ext/opcache/jit/zend_jit_disasm_x86.c
+++ b/ext/opcache/jit/zend_jit_disasm_x86.c
@@ -421,6 +421,7 @@ static int zend_jit_disasm_init(void)
 	REGISTER_HELPER(zend_jit_fetch_dim_r_helper);
 	REGISTER_HELPER(zend_jit_fetch_dim_is_helper);
 	REGISTER_HELPER(zend_jit_fetch_dim_isset_helper);
+	REGISTER_HELPER(zend_jit_fetch_dim_str_offset_r_helper);
 	REGISTER_HELPER(zend_jit_fetch_dim_str_r_helper);
 	REGISTER_HELPER(zend_jit_fetch_dim_str_is_helper);
 	REGISTER_HELPER(zend_jit_fetch_dim_obj_r_helper);
diff --git a/ext/opcache/jit/zend_jit_helpers.c b/ext/opcache/jit/zend_jit_helpers.c
index c366e6274a..11912e3a70 100644
--- a/ext/opcache/jit/zend_jit_helpers.c
+++ b/ext/opcache/jit/zend_jit_helpers.c
@@ -834,7 +834,30 @@ try_again:
 	return _zval_get_long_func(dim);
 }
 
-static void ZEND_FASTCALL zend_jit_fetch_dim_str_r_helper(zval *container, zval *dim, zval *result)
+static zend_always_inline zend_string* zend_jit_fetch_dim_str_offset(zend_string *str, zend_long offset)
+{
+	if (UNEXPECTED((zend_ulong)offset >= (zend_ulong)ZSTR_LEN(str))) {
+		if (EXPECTED(offset < 0)) {
+			/* Handle negative offset */
+			zend_long real_offset = (zend_long)ZSTR_LEN(str) + offset;
+
+			if (EXPECTED(real_offset >= 0)) {
+				return ZSTR_CHAR((zend_uchar)ZSTR_VAL(str)[real_offset]);
+			}
+		}
+		zend_error(E_WARNING, "Uninitialized string offset " ZEND_LONG_FMT, offset);
+		return ZSTR_EMPTY_ALLOC();
+	} else {
+		return ZSTR_CHAR((zend_uchar)ZSTR_VAL(str)[offset]);
+	}
+}
+
+static zend_string* ZEND_FASTCALL zend_jit_fetch_dim_str_offset_r_helper(zend_string *str, zend_long offset)
+{
+	return zend_jit_fetch_dim_str_offset(str, offset);
+}
+
+static zend_string* ZEND_FASTCALL zend_jit_fetch_dim_str_r_helper(zend_string *str, zval *dim)
 {
 	zend_long offset;
 
@@ -843,22 +866,10 @@ static void ZEND_FASTCALL zend_jit_fetch_dim_str_r_helper(zval *container, zval
 	} else {
 		offset = Z_LVAL_P(dim);
 	}
-
-	if (UNEXPECTED(Z_STRLEN_P(container) < ((offset < 0) ? -(size_t)offset : ((size_t)offset + 1)))) {
-		zend_error(E_WARNING, "Uninitialized string offset " ZEND_LONG_FMT, offset);
-		ZVAL_EMPTY_STRING(result);
-	} else {
-		zend_uchar c;
-		zend_long real_offset;
-
-		real_offset = (UNEXPECTED(offset < 0)) /* Handle negative offset */
-			? (zend_long)Z_STRLEN_P(container) + offset : offset;
-		c = (zend_uchar)Z_STRVAL_P(container)[real_offset];
-		ZVAL_CHAR(result, c);
-	}
+	return zend_jit_fetch_dim_str_offset(str, offset);
 }
 
-static void ZEND_FASTCALL zend_jit_fetch_dim_str_is_helper(zval *container, zval *dim, zval *result)
+static void ZEND_FASTCALL zend_jit_fetch_dim_str_is_helper(zend_string *str, zval *dim, zval *result)
 {
 	zend_long offset;
 
@@ -892,16 +903,19 @@ try_string_offset:
 		offset = Z_LVAL_P(dim);
 	}
 
-	if (UNEXPECTED(Z_STRLEN_P(container) < ((offset < 0) ? -(size_t)offset : ((size_t)offset + 1)))) {
+	if ((zend_ulong)offset >= (zend_ulong)ZSTR_LEN(str)) {
+		if (offset < 0) {
+			/* Handle negative offset */
+			zend_long real_offset = (zend_long)ZSTR_LEN(str) + offset;
+
+			if (real_offset >= 0) {
+				ZVAL_CHAR(result, (zend_uchar)ZSTR_VAL(str)[real_offset]);
+				return;
+			}
+		}
 		ZVAL_NULL(result);
 	} else {
-		zend_uchar c;
-		zend_long real_offset;
-
-		real_offset = (UNEXPECTED(offset < 0)) /* Handle negative offset */
-			? (zend_long)Z_STRLEN_P(container) + offset : offset;
-		c = (zend_uchar)Z_STRVAL_P(container)[real_offset];
-		ZVAL_CHAR(result, c);
+		ZVAL_CHAR(result, (zend_uchar)ZSTR_VAL(str)[offset]);
 	}
 }
 
diff --git a/ext/opcache/jit/zend_jit_x86.dasc b/ext/opcache/jit/zend_jit_x86.dasc
index ee998a69e4..53dbb9b225 100644
--- a/ext/opcache/jit/zend_jit_x86.dasc
+++ b/ext/opcache/jit/zend_jit_x86.dasc
@@ -11623,24 +11623,30 @@ static int zend_jit_fetch_dim_read(dasm_State        **Dst,
 				}
 			}
 			|	SET_EX_OPLINE opline, r0
-		    if (Z_REG(op1_addr) != ZREG_FCARG1a || Z_OFFSET(op1_addr) != 0) {
-				|	LOAD_ZVAL_ADDR FCARG1a, op1_addr
-		    }
-			|	LOAD_ZVAL_ADDR FCARG2a, op2_addr
-			|.if X64
-				|   LOAD_ZVAL_ADDR CARG3, res_addr
-			|.else
-				|	sub r4, 12
-				|   PUSH_ZVAL_ADDR res_addr, r0
-			|.endif
+			|	GET_ZVAL_LVAL ZREG_FCARG1a, op1_addr
 			if (opline->opcode != ZEND_FETCH_DIM_IS) {
-				|	EXT_CALL zend_jit_fetch_dim_str_r_helper, r0
+				if ((op2_info & (MAY_BE_ANY|MAY_BE_UNDEF|MAY_BE_GUARD)) == MAY_BE_LONG) {
+					|	GET_ZVAL_LVAL ZREG_FCARG2a, op2_addr
+					|	EXT_CALL zend_jit_fetch_dim_str_offset_r_helper, r0
+				} else {
+					|	LOAD_ZVAL_ADDR FCARG2a, op2_addr
+					|	EXT_CALL zend_jit_fetch_dim_str_r_helper, r0
+				}
+				|	SET_ZVAL_PTR res_addr, r0
+				|	SET_ZVAL_TYPE_INFO res_addr, IS_STRING
 			} else {
+				|	LOAD_ZVAL_ADDR FCARG2a, op2_addr
+				|.if X64
+					|   LOAD_ZVAL_ADDR CARG3, res_addr
+				|.else
+					|	sub r4, 12
+					|   PUSH_ZVAL_ADDR res_addr, r0
+				|.endif
 				|	EXT_CALL zend_jit_fetch_dim_str_is_helper, r0
+				|.if not(X64)
+				|	add r4, 12
+				|.endif
 			}
-			|.if not(X64)
-			|	add r4, 12
-			|.endif
 			if ((op1_info & MAY_BE_ARRAY) ||
 				(op1_info & ((MAY_BE_ANY|MAY_BE_UNDEF)-(MAY_BE_ARRAY|MAY_BE_STRING)))) {
 				|	jmp >9 // END