diff --git a/compiler-rt/lib/asan/asan_allocator.cc b/compiler-rt/lib/asan/asan_allocator.cc
index 89746eb618f4..60d8671c4aff 100644
--- a/compiler-rt/lib/asan/asan_allocator.cc
+++ b/compiler-rt/lib/asan/asan_allocator.cc
@@ -46,24 +46,17 @@ static const size_t kMinAllocSize = REDZONE * 2;
 static const uint64_t kMaxAvailableRam = 128ULL << 30;  // 128G
 static const size_t kMaxThreadLocalQuarantine = 1 << 20;  // 1M
 
-#if ASAN_LOW_MEMORY == 1
-static const size_t kMinMmapSize  = 4UL << 17;  // 128K
-  static const size_t kMaxSizeForThreadLocalFreeList = 1 << 15;  // 32K
-#else
-static const size_t kMinMmapSize  = 4UL << 20;  // 4M
-  static const size_t kMaxSizeForThreadLocalFreeList = 1 << 17;  // 128K
-#endif
+static const size_t kMinMmapSize = (ASAN_LOW_MEMORY) ? 4UL << 17 : 4UL << 20;
+static const size_t kMaxSizeForThreadLocalFreeList =
+    (ASAN_LOW_MEMORY) ? 1 << 15 : 1 << 17;
 
 // Size classes less than kMallocSizeClassStep are powers of two.
 // All other size classes are multiples of kMallocSizeClassStep.
 static const size_t kMallocSizeClassStepLog = 26;
 static const size_t kMallocSizeClassStep = 1UL << kMallocSizeClassStepLog;
 
-#if __WORDSIZE == 32
-static const size_t kMaxAllowedMallocSize = 3UL << 30;  // 3G
-#else
-static const size_t kMaxAllowedMallocSize = 8UL << 30;  // 8G
-#endif
+static const size_t kMaxAllowedMallocSize =
+    (__WORDSIZE == 32) ? 3UL << 30 : 8UL << 30;
 
 static inline bool IsAligned(uintptr_t a, uintptr_t alignment) {
   return (a & (alignment - 1)) == 0;
diff --git a/compiler-rt/lib/asan/asan_internal.h b/compiler-rt/lib/asan/asan_internal.h
index fde24d597a82..8acd36274e11 100644
--- a/compiler-rt/lib/asan/asan_internal.h
+++ b/compiler-rt/lib/asan/asan_internal.h
@@ -129,6 +129,12 @@ extern "C" void* _ReturnAddress(void);
 # define ASAN_FLEXIBLE_MAPPING_AND_OFFSET 0
 #endif
 
+// If set, values like allocator chunk size, as well as defaults for some flags
+// will be changed towards less memory overhead.
+#ifndef ASAN_LOW_MEMORY
+# define ASAN_LOW_MEMORY 0
+#endif
+
 // All internal functions in asan reside inside the __asan namespace
 // to avoid namespace collisions with the user programs.
 // Seperate namespace also makes it simpler to distinguish the asan run-time
diff --git a/compiler-rt/lib/asan/asan_rtl.cc b/compiler-rt/lib/asan/asan_rtl.cc
index fff199bf3528..4075d1f63fa4 100644
--- a/compiler-rt/lib/asan/asan_rtl.cc
+++ b/compiler-rt/lib/asan/asan_rtl.cc
@@ -410,15 +410,8 @@ void __asan_init() {
 
   FLAG_v = IntFlagValue(options, "verbosity=", 0);
 
-#if ASAN_LOW_MEMORY == 1
-  FLAG_quarantine_size =
-    IntFlagValue(options, "quarantine_size=", 1UL << 24);  // 16M
-  FLAG_redzone = IntFlagValue(options, "redzone=", 64);
-#else
-  FLAG_quarantine_size =
-    IntFlagValue(options, "quarantine_size=", 1UL << 28);  // 256M
-  FLAG_redzone = IntFlagValue(options, "redzone=", 128);
-#endif
+  FLAG_redzone = IntFlagValue(options, "redzone=",
+      (ASAN_LOW_MEMORY) ? 64 : 128);
   CHECK(FLAG_redzone >= 32);
   CHECK((FLAG_redzone & (FLAG_redzone - 1)) == 0);
 
@@ -443,6 +436,9 @@ void __asan_init() {
     Atexit(asan_atexit);
   }
 
+  FLAG_quarantine_size = IntFlagValue(options, "quarantine_size=",
+      (ASAN_LOW_MEMORY) ? 1UL << 24 : 1UL << 28);
+
   // interceptors
   InitializeAsanInterceptors();
 
diff --git a/compiler-rt/lib/asan/tests/asan_test.cc b/compiler-rt/lib/asan/tests/asan_test.cc
index 733b3dbc8f11..7a3819858850 100644
--- a/compiler-rt/lib/asan/tests/asan_test.cc
+++ b/compiler-rt/lib/asan/tests/asan_test.cc
@@ -453,11 +453,7 @@ static void MallocStress(size_t n) {
 }
 
 TEST(AddressSanitizer, MallocStressTest) {
-#if ASAN_LOW_MEMORY == 1
-  MallocStress(20000);
-#else
-  MallocStress(200000);
-#endif
+  MallocStress((ASAN_LOW_MEMORY) ? 20000 : 200000);
 }
 
 static void TestLargeMalloc(size_t size) {
@@ -489,13 +485,11 @@ TEST(AddressSanitizer, HugeMallocTest) {
 
 TEST(AddressSanitizer, ThreadedMallocStressTest) {
   const int kNumThreads = 4;
+  const int kNumIterations = (ASAN_LOW_MEMORY) ? 10000 : 100000;
   pthread_t t[kNumThreads];
   for (int i = 0; i < kNumThreads; i++) {
-#if ASAN_LOW_MEMORY == 1
-    pthread_create(&t[i], 0, (void* (*)(void *x))MallocStress, (void*)10000);
-#else
-    pthread_create(&t[i], 0, (void* (*)(void *x))MallocStress, (void*)100000);
-#endif
+    pthread_create(&t[i], 0, (void* (*)(void *x))MallocStress,
+        (void*)kNumIterations);
   }
   for (int i = 0; i < kNumThreads; i++) {
     pthread_join(t[i], 0);