JIT: prefer string reallocation instead of allocation/memcpy/dealloca…

…tion
php · Sep 7, 2021 · 7fcb45d · 7fcb45d
1 parent aed94e2
commit 7fcb45d
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Showing 4 changed files with 45 additions and 6 deletions.
diff --git a/ext/opcache/jit/zend_jit_arm64.dasc b/ext/opcache/jit/zend_jit_arm64.dasc
@@ -4804,12 +4804,14 @@ static int zend_jit_concat_helper(dasm_State    **Dst,
 			}
 			|	LOAD_ZVAL_ADDR FCARG2x, op1_addr
 			|	LOAD_ZVAL_ADDR CARG3, op2_addr
-			|	EXT_CALL zend_jit_fast_concat_helper, REG0
+			if (op1_type == IS_CV || op1_type == IS_CONST) {
+				|	EXT_CALL zend_jit_fast_concat_helper, REG0
+			} else {
+				|	EXT_CALL zend_jit_fast_concat_tmp_helper, REG0
+			}
 		}
 		/* concatination with empty string may increase refcount */
-		op1_info |= MAY_BE_RCN;
 		op2_info |= MAY_BE_RCN;
-		|	FREE_OP op1_type, op1, op1_info, 0, opline, ZREG_TMP1, ZREG_TMP2
 		|	FREE_OP op2_type, op2, op2_info, 0, opline, ZREG_TMP1, ZREG_TMP2
 		|5:
 	}

diff --git a/ext/opcache/jit/zend_jit_disasm.c b/ext/opcache/jit/zend_jit_disasm.c
@@ -637,6 +637,7 @@ static int zend_jit_disasm_init(void)
 	REGISTER_HELPER(zend_jit_assign_dim_op_helper);
 	REGISTER_HELPER(zend_jit_fast_assign_concat_helper);
 	REGISTER_HELPER(zend_jit_fast_concat_helper);
+	REGISTER_HELPER(zend_jit_fast_concat_tmp_helper);
 	REGISTER_HELPER(zend_jit_isset_dim_helper);
 	REGISTER_HELPER(zend_jit_free_call_frame);
 	REGISTER_HELPER(zend_jit_fetch_global_helper);

diff --git a/ext/opcache/jit/zend_jit_helpers.c b/ext/opcache/jit/zend_jit_helpers.c
@@ -1265,6 +1265,40 @@ static void ZEND_FASTCALL zend_jit_fast_concat_helper(zval *result, zval *op1, z
 	ZSTR_VAL(result_str)[result_len] = '\0';
 }
 
+static void ZEND_FASTCALL zend_jit_fast_concat_tmp_helper(zval *result, zval *op1, zval *op2)
+{
+	zend_string *op1_str = Z_STR_P(op1);
+	size_t op1_len = ZSTR_LEN(op1_str);
+	size_t op2_len = Z_STRLEN_P(op2);
+	size_t result_len = op1_len + op2_len;
+	zend_string *result_str;
+
+	if (UNEXPECTED(op1_len > SIZE_MAX - op2_len)) {
+		zend_throw_error(NULL, "String size overflow");
+		return;
+	}
+
+	do {
+		if (!ZSTR_IS_INTERNED(op1_str)) {
+			if (GC_REFCOUNT(op1_str) == 1) {
+				Z_STR_P(op1) = result_str =
+					perealloc(op1_str, ZEND_MM_ALIGNED_SIZE(_ZSTR_STRUCT_SIZE(result_len)), 0);
+				ZSTR_LEN(result_str) = result_len;
+				zend_string_forget_hash_val(result_str);
+				break;
+			}
+			GC_DELREF(op1_str);
+		}
+		result_str = zend_string_alloc(result_len, 0);
+		memcpy(ZSTR_VAL(result_str), ZSTR_VAL(op1_str), op1_len);
+	} while (0);
+
+	ZVAL_NEW_STR(result, result_str);
+
+	memcpy(ZSTR_VAL(result_str) + op1_len, Z_STRVAL_P(op2), op2_len);
+	ZSTR_VAL(result_str)[result_len] = '\0';
+}
+
 static int ZEND_FASTCALL zend_jit_isset_dim_helper(zval *container, zval *offset)
 {
 	if (UNEXPECTED(Z_TYPE_P(offset) == IS_UNDEF)) {

diff --git a/ext/opcache/jit/zend_jit_x86.dasc b/ext/opcache/jit/zend_jit_x86.dasc
@@ -5251,15 +5251,17 @@ static int zend_jit_concat_helper(dasm_State    **Dst,
 				|	sub r4, 12
 				|	PUSH_ZVAL_ADDR op2_addr, r0
 			|.endif
-			|	EXT_CALL zend_jit_fast_concat_helper, r0
+			if (op1_type == IS_CV || op1_type == IS_CONST) {
+				|	EXT_CALL zend_jit_fast_concat_helper, r0
+			} else {
+				|	EXT_CALL zend_jit_fast_concat_tmp_helper, r0
+			}
 			|.if not(X64)
 			|	add r4, 12
 			|.endif
 		}
 		/* concatination with empty string may increase refcount */
-		op1_info |= MAY_BE_RCN;
 		op2_info |= MAY_BE_RCN;
-		|	FREE_OP op1_type, op1, op1_info, 0, opline
 		|	FREE_OP op2_type, op2, op2_info, 0, opline
 		|5:
 	}