diff --git a/compiler-rt/lib/asan/asan_allocator.h b/compiler-rt/lib/asan/asan_allocator.h
index 06cabe60ff7ce87405008777996fff33f969181e..ac7adc627411590d94199bae239d9a0b4d67de3b 100644
--- a/compiler-rt/lib/asan/asan_allocator.h
+++ b/compiler-rt/lib/asan/asan_allocator.h
@@ -24,7 +24,7 @@
 // will co-exist in the source base for a while. The actual allocator is chosen
 // at build time by redefining this macro.
 #ifndef ASAN_ALLOCATOR_VERSION
-# if (ASAN_LINUX && !ASAN_ANDROID) || ASAN_MAC
+# if (ASAN_LINUX && !ASAN_ANDROID) || ASAN_MAC || ASAN_WINDOWS
 #  define ASAN_ALLOCATOR_VERSION 2
 # else
 #  define ASAN_ALLOCATOR_VERSION 1
diff --git a/compiler-rt/lib/asan/asan_allocator2.cc b/compiler-rt/lib/asan/asan_allocator2.cc
index 5854d0ffd4a8cecf46986d5c5cd57e0b9501da6e..039d1b0c9855ad19fa1acd61ac275e1832dacbac 100644
--- a/compiler-rt/lib/asan/asan_allocator2.cc
+++ b/compiler-rt/lib/asan/asan_allocator2.cc
@@ -115,7 +115,7 @@ static u32 RZSize2Log(u32 rz_size) {
   CHECK_GE(rz_size, 16);
   CHECK_LE(rz_size, 2048);
   CHECK(IsPowerOfTwo(rz_size));
-  u32 res = __builtin_ctz(rz_size) - 4;
+  u32 res = Log2(rz_size) - 4;
   CHECK_EQ(rz_size, RZLog2Size(res));
   return res;
 }
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_allocator.h b/compiler-rt/lib/sanitizer_common/sanitizer_allocator.h
index c0d7b5e2d9a5d139ef1c90d029ccf055c8766bdc..48e5b1afc40cb2d6f15784e2cf9a078226fe6b1c 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_allocator.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_allocator.h
@@ -121,7 +121,7 @@ class SizeClassMap {
     if (size <= kMidSize)
       return (size + kMinSize - 1) >> kMinSizeLog;
     if (size > kMaxSize) return 0;
-    uptr l = SANITIZER_WORDSIZE - 1 - __builtin_clzl(size);
+    uptr l = MostSignificantSetBitIndex(size);
     uptr hbits = (size >> (l - S)) & M;
     uptr lbits = size & ((1 << (l - S)) - 1);
     uptr l1 = l - kMidSizeLog;
@@ -143,7 +143,7 @@ class SizeClassMap {
         Printf("\n");
       uptr d = s - prev_s;
       uptr p = prev_s ? (d * 100 / prev_s) : 0;
-      uptr l = SANITIZER_WORDSIZE - 1 - __builtin_clzl(s);
+      uptr l = MostSignificantSetBitIndex(s);
       uptr cached = MaxCached(i) * s;
       Printf("c%02zd => s: %zd diff: +%zd %02zd%% l %zd "
              "cached: %zd %zd; id %zd\n",
@@ -886,7 +886,7 @@ class LargeMmapAllocator {
     h->size = size;
     h->map_beg = map_beg;
     h->map_size = map_size;
-    uptr size_log = SANITIZER_WORDSIZE - __builtin_clzl(map_size) - 1;
+    uptr size_log = MostSignificantSetBitIndex(map_size);
     CHECK_LT(size_log, ARRAY_SIZE(stats.by_size_log));
     {
       SpinMutexLock l(&mutex_);
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_quarantine.h b/compiler-rt/lib/sanitizer_common/sanitizer_quarantine.h
index b756a706fedea5a5e2d63d13a9491a00c4fa7e67..599d13645dd795a266e2c1ff71c0a8dcafc3ad85 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_quarantine.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_quarantine.h
@@ -159,7 +159,7 @@ class QuarantineCache {
     atomic_store(&size_, Size() + add, memory_order_relaxed);
   }
 
-  QuarantineBatch *NOINLINE AllocBatch(Callback cb) {
+  NOINLINE QuarantineBatch* AllocBatch(Callback cb) {
     QuarantineBatch *b = (QuarantineBatch *)cb.Allocate(sizeof(*b));
     b->count = 0;
     b->size = 0;
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_win.cc b/compiler-rt/lib/sanitizer_common/sanitizer_win.cc
index 32d5e1e1d7b6f48a0c47ad41b30c9943231cc730..2ce3c352a8bed2485f7ec25bdc45779e46fdc84b 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_win.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_win.cc
@@ -97,6 +97,11 @@ void *Mprotect(uptr fixed_addr, uptr size) {
                       MEM_RESERVE | MEM_COMMIT, PAGE_NOACCESS);
 }
 
+void FlushUnneededShadowMemory(uptr addr, uptr size) {
+  // This is almost useless on 32-bits.
+  // FIXME: add madvice-analog when we move to 64-bits.
+}
+
 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
   // FIXME: shall we do anything here on Windows?
   return true;