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[asan] speedup by more than 2x handling of the small memset/memcpy/etc calls 

llvm-svn: 175728
This commit is contained in:
Kostya Serebryany 2013-02-21 07:07:39 +00:00
parent 9e722aed4a
commit ab5be26af5
3 changed files with 23 additions and 3 deletions
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13
compiler-rt/lib/asan/asan_interceptors.cc
View File

@ -26,6 +26,16 @@
namespace __asan {
// Return true if we can quickly decide that the region is unpoisoned.
static inline bool QuickCheckForUnpoisonedRegion(uptr beg, uptr size) {
if (size == 0) return true;
if (size <= 32)
return !AddressIsPoisoned(beg) &&
!AddressIsPoisoned(beg + size - 1) &&
!AddressIsPoisoned(beg + size / 2);
return false;
}
// We implement ACCESS_MEMORY_RANGE, ASAN_READ_RANGE,
// and ASAN_WRITE_RANGE as macro instead of function so
// that no extra frames are created, and stack trace contains
@ -34,7 +44,8 @@ namespace __asan {
#define ACCESS_MEMORY_RANGE(offset, size, isWrite) do { \
uptr __offset = (uptr)(offset); \
uptr __size = (uptr)(size); \
if (__asan_region_is_poisoned(__offset, __size)) { \
if (!QuickCheckForUnpoisonedRegion(__offset, __size) && \
__asan_region_is_poisoned(__offset, __size)) { \
GET_CURRENT_PC_BP_SP; \
__asan_report_error(pc, bp, sp, __offset, isWrite, __size); \
} \

2
compiler-rt/lib/asan/asan_mapping.h
View File

@ -206,7 +206,7 @@ static inline bool AddrIsAlignedByGranularity(uptr a) {
static inline bool AddressIsPoisoned(uptr a) {
PROFILE_ASAN_MAPPING();
const uptr kAccessSize = 1;
u8 *shadow_address = (u8*)MemToShadow(a);
u8 *shadow_address = (u8*)MEM_TO_SHADOW(a);
s8 shadow_value = *shadow_address;
if (shadow_value) {
u8 last_accessed_byte = (a & (SHADOW_GRANULARITY - 1))

11
compiler-rt/lib/asan/tests/asan_noinst_test.cc
View File

@ -764,7 +764,7 @@ TEST(AddressSanitizerInterface, PoisonedRegion) {
// 10.50% [.] __sanitizer::mem_is_zero
// I.e. mem_is_zero should consume ~ SHADOW_GRANULARITY less CPU cycles
// than memset itself.
TEST(AddressSanitizerInterface, DISABLED_Stress_memset) {
TEST(AddressSanitizerInterface, DISABLED_StressLargeMemset) {
size_t size = 1 << 20;
char *x = new char[size];
for (int i = 0; i < 100000; i++)
@ -772,6 +772,15 @@ TEST(AddressSanitizerInterface, DISABLED_Stress_memset) {
delete [] x;
}
// Same here, but we run memset with small sizes.
TEST(AddressSanitizerInterface, DISABLED_StressSmallMemset) {
size_t size = 32;
char *x = new char[size];
for (int i = 0; i < 100000000; i++)
Ident(memset)(x, 0, size);
delete [] x;
}
static const char *kInvalidPoisonMessage = "invalid-poison-memory-range";
static const char *kInvalidUnpoisonMessage = "invalid-unpoison-memory-range";