1 /*
2  * Copyright 2018 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #ifndef SkSafe32_DEFINED
9 #define SkSafe32_DEFINED
10 
11 static constexpr int32_t Sk64_pin_to_s32(int64_t x) {
12     return x < SK_MinS32 ? SK_MinS32 : (x > SK_MaxS32 ? SK_MaxS32 : x);
13 }
14 
15 static constexpr int32_t Sk32_sat_add(int32_t a, int32_t b) {
16     return Sk64_pin_to_s32((int64_t)a + (int64_t)b);
17 }
18 
19 static constexpr int32_t Sk32_sat_sub(int32_t a, int32_t b) {
20     return Sk64_pin_to_s32((int64_t)a - (int64_t)b);
21 }
22 
23 // To avoid UBSAN complaints about 2's compliment overflows
24 //
25 static constexpr int32_t Sk32_can_overflow_sub(int32_t a, int32_t b) {
26     return (int32_t)((uint32_t)a - (uint32_t)b);
27 }
28 
29 #endif
30