diff --git a/compiler-rt/lib/asan/asan_mapping.h b/compiler-rt/lib/asan/asan_mapping.h
--- a/compiler-rt/lib/asan/asan_mapping.h
+++ b/compiler-rt/lib/asan/asan_mapping.h
@@ -279,10 +279,34 @@
 #    define kLowShadowBeg ASAN_SHADOW_OFFSET
 #    define kLowShadowEnd MEM_TO_SHADOW(kLowMemEnd)
 
+#if !SANITIZER_IOS
 #    define kHighMemBeg (MEM_TO_SHADOW(kHighMemEnd) + 1)
 
 #    define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg)
 #    define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd)
+#else // !SANITIZER_IOS
+#    define IS_HIGH_MEM_LOW kHighMemEnd <= (MEM_TO_SHADOW(kHighMemEnd) + 1)
+// The above expression decides whether defining the
+// kHighMemBeg, kHighShadowBeg and kHighShadowEnd macros as in !SANITIZER_IOS case
+// leads to nonsensical situation where kHighMemEnd <= (MEM_TO_SHADOW(kHighMemEnd) + 1)
+// If so, the alternate memory layout will be used
+#    define kHighMemBeg \
+        ( IS_HIGH_MEM_LOW ? \
+          RoundUpTo(kLowShadowEnd + ((kHighMemEnd - kLowShadowEnd) >> ASAN_SHADOW_SCALE) , GetMmapGranularity()) : \
+          MEM_TO_SHADOW(kHighMemEnd) + 1 \
+        )
+
+#    define kHighShadowBeg \
+        ( IS_HIGH_MEM_LOW ? \
+          kLowShadowEnd + 1 + GetMmapGranularity() : \
+          MEM_TO_SHADOW(kHighMemBeg) \
+        )
+#    define kHighShadowEnd \
+        ( IS_HIGH_MEM_LOW ? \
+          RoundUpTo(kLowShadowEnd + ((kHighMemEnd - kLowShadowEnd) >> ASAN_SHADOW_SCALE) , GetMmapGranularity()) - 1  : \
+          MEM_TO_SHADOW(kHighMemEnd) \
+        )
+#endif // !SANITIZER_IOS
 
 #    define kMidShadowBeg MEM_TO_SHADOW(kMidMemBeg)
 #    define kMidShadowEnd MEM_TO_SHADOW(kMidMemEnd)