skia2/include/private/SkSafe32.h
Mike Reed 36c0b57698 use safe increment for edge walker
Bug: oss-fuzz:6126
Change-Id: I8f6865cbbbfbe37acf940cc2d4ae93204ba7168d
Reviewed-on: https://skia-review.googlesource.com/107783
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
2018-02-15 17:14:19 +00:00

33 lines
876 B
C

/*
* Copyright 2018 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkSafe32_DEFINED
#define SkSafe32_DEFINED
static constexpr int32_t Sk64_pin_to_s32(int64_t x) {
return x < SK_MinS32 ? SK_MinS32 : (x > SK_MaxS32 ? SK_MaxS32 : x);
}
static constexpr int32_t Sk32_sat_add(int32_t a, int32_t b) {
return Sk64_pin_to_s32((int64_t)a + (int64_t)b);
}
static constexpr int32_t Sk32_sat_sub(int32_t a, int32_t b) {
return Sk64_pin_to_s32((int64_t)a - (int64_t)b);
}
// To avoid UBSAN complaints about 2's compliment overflows
//
static constexpr int32_t Sk32_can_overflow_add(int32_t a, int32_t b) {
return (int32_t)((uint32_t)a + (uint32_t)b);
}
static constexpr int32_t Sk32_can_overflow_sub(int32_t a, int32_t b) {
return (int32_t)((uint32_t)a - (uint32_t)b);
}
#endif