diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -2552,13 +2552,20 @@
   constexpr uint64_t kMaxRZ = 1 << 18;
   const uint64_t MinRZ = getMinRedzoneSizeForGlobal();
 
-  // Calculate RZ, where MinRZ <= RZ <= MaxRZ, and RZ ~ 1/4 * SizeInBytes.
-  uint64_t RZ =
-      std::max(MinRZ, std::min(kMaxRZ, (SizeInBytes / MinRZ / 4) * MinRZ));
+  uint64_t RZ = 0;
+  // Reduce redzone size for small size objects, e.g. int, char[1]. MinRZ is at
+  // least 32 bytes, optimize when SizeInBytes is less than half of MinRZ.
+  if (SizeInBytes < MinRZ / 2) {
+    RZ = MinRZ - SizeInBytes;
+  } else {
+    // Calculate RZ, where MinRZ <= RZ <= MaxRZ, and RZ ~ 1/4 * SizeInBytes.
+    RZ = std::max(MinRZ, std::min(kMaxRZ, (SizeInBytes / MinRZ / 4) * MinRZ));
+
+    // Round up to multiple of MinRZ.
+    if (SizeInBytes % MinRZ)
+      RZ += MinRZ - (SizeInBytes % MinRZ);
+  }
 
-  // Round up to multiple of MinRZ.
-  if (SizeInBytes % MinRZ)
-    RZ += MinRZ - (SizeInBytes % MinRZ);
   assert((RZ + SizeInBytes) % MinRZ == 0);
 
   return RZ;
diff --git a/llvm/test/Instrumentation/AddressSanitizer/AMDGPU/adaptive_constant_global_redzones.ll b/llvm/test/Instrumentation/AddressSanitizer/AMDGPU/adaptive_constant_global_redzones.ll
--- a/llvm/test/Instrumentation/AddressSanitizer/AMDGPU/adaptive_constant_global_redzones.ll
+++ b/llvm/test/Instrumentation/AddressSanitizer/AMDGPU/adaptive_constant_global_redzones.ll
@@ -7,7 +7,7 @@
 ; for objects in constant address space.
 
 @G10 = addrspace(4) global [10 x i8] zeroinitializer, align 1
-; CHECK: @G10 = addrspace(4) global { [10 x i8], [54 x i8] }
+; CHECK: @G10 = addrspace(4) global { [10 x i8], [22 x i8] }
 
 @G31 = addrspace(4) global [31 x i8] zeroinitializer, align 1
 @G32 = addrspace(4) global [32 x i8] zeroinitializer, align 1
diff --git a/llvm/test/Instrumentation/AddressSanitizer/AMDGPU/adaptive_global_redzones.ll b/llvm/test/Instrumentation/AddressSanitizer/AMDGPU/adaptive_global_redzones.ll
--- a/llvm/test/Instrumentation/AddressSanitizer/AMDGPU/adaptive_global_redzones.ll
+++ b/llvm/test/Instrumentation/AddressSanitizer/AMDGPU/adaptive_global_redzones.ll
@@ -7,7 +7,7 @@
 ; for objects in global address space.
 
 @G10 = addrspace(1) global [10 x i8] zeroinitializer, align 1
-; CHECK: @G10 = addrspace(1) global { [10 x i8], [54 x i8] }
+; CHECK: @G10 = addrspace(1) global { [10 x i8], [22 x i8] }
 
 @G31 = addrspace(1) global [31 x i8] zeroinitializer, align 1
 @G32 = addrspace(1) global [32 x i8] zeroinitializer, align 1
diff --git a/llvm/test/Instrumentation/AddressSanitizer/adaptive_global_redzones.ll b/llvm/test/Instrumentation/AddressSanitizer/adaptive_global_redzones.ll
--- a/llvm/test/Instrumentation/AddressSanitizer/adaptive_global_redzones.ll
+++ b/llvm/test/Instrumentation/AddressSanitizer/adaptive_global_redzones.ll
@@ -8,7 +8,7 @@
 ; Here we check that the global redzone sizes grow with the object size.
 
 @G10 = global [10 x i8] zeroinitializer, align 1
-; CHECK: @G10 = global { [10 x i8], [54 x i8] }
+; CHECK: @G10 = global { [10 x i8], [22 x i8] }
 
 @G31 = global [31 x i8] zeroinitializer, align 1
 @G32 = global [32 x i8] zeroinitializer, align 1
diff --git a/llvm/test/Instrumentation/AddressSanitizer/debug-info-global-var.ll b/llvm/test/Instrumentation/AddressSanitizer/debug-info-global-var.ll
--- a/llvm/test/Instrumentation/AddressSanitizer/debug-info-global-var.ll
+++ b/llvm/test/Instrumentation/AddressSanitizer/debug-info-global-var.ll
@@ -3,7 +3,7 @@
 source_filename = "version.c"
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-apple-macosx10.12.0"
-; CHECK: @version = constant { [5 x i8], [59 x i8] } {{.*}}, !dbg ![[GV:.*]]
+; CHECK: @version = constant { [5 x i8], [27 x i8] } {{.*}}, !dbg ![[GV:.*]]
 
 @version = constant [5 x i8] c"4.00\00", align 1, !dbg !0
 
diff --git a/llvm/test/Instrumentation/AddressSanitizer/global_cstring_darwin.ll b/llvm/test/Instrumentation/AddressSanitizer/global_cstring_darwin.ll
--- a/llvm/test/Instrumentation/AddressSanitizer/global_cstring_darwin.ll
+++ b/llvm/test/Instrumentation/AddressSanitizer/global_cstring_darwin.ll
@@ -9,14 +9,14 @@
 @.str.1 = private unnamed_addr constant [13 x i8] c"Hello world.\00", align 1
 @.str.2 = private unnamed_addr constant [4 x i8] c"%s\0A\00", align 1
 
-; CHECK: @.str.1 = internal constant { [13 x i8], [51 x i8] } { [13 x i8] c"Hello world.\00", [51 x i8] zeroinitializer }, section "__TEXT,__asan_cstring,regular", align 32
-; CHECK: @.str.2 = internal constant { [4 x i8], [60 x i8] } { [4 x i8] c"%s\0A\00", [60 x i8] zeroinitializer }, section "__TEXT,__asan_cstring,regular", align 32
+; CHECK: @.str.1 = internal constant { [13 x i8], [19 x i8] } { [13 x i8] c"Hello world.\00", [19 x i8] zeroinitializer }, section "__TEXT,__asan_cstring,regular", align 32
+; CHECK: @.str.2 = internal constant { [4 x i8], [28 x i8] } { [4 x i8] c"%s\0A\00", [28 x i8] zeroinitializer }, section "__TEXT,__asan_cstring,regular", align 32
 
 ; Shouldn't be put into special section:
 @.str.3 = private unnamed_addr constant [4 x i8] c"\00\01\02\03", align 1
 @.str.4 = private unnamed_addr global [7 x i8] c"Hello.\00", align 1
 @.str.5 = private unnamed_addr constant [8 x i8] c"Hello.\00\00", align 1
 
-; CHECK: @.str.3 = internal constant { [4 x i8], [60 x i8] } { [4 x i8] c"\00\01\02\03", [60 x i8] zeroinitializer }, align 32
-; CHECK: @.str.4 = private global { [7 x i8], [57 x i8] } { [7 x i8] c"Hello.\00", [57 x i8] zeroinitializer }, align 32
-; CHECK: @.str.5 = internal constant { [8 x i8], [56 x i8] } { [8 x i8] c"Hello.\00\00", [56 x i8] zeroinitializer }, align 32
+; CHECK: @.str.3 = internal constant { [4 x i8], [28 x i8] } { [4 x i8] c"\00\01\02\03", [28 x i8] zeroinitializer }, align 32
+; CHECK: @.str.4 = private global { [7 x i8], [25 x i8] } { [7 x i8] c"Hello.\00", [25 x i8] zeroinitializer }, align 32
+; CHECK: @.str.5 = internal constant { [8 x i8], [24 x i8] } { [8 x i8] c"Hello.\00\00", [24 x i8] zeroinitializer }, align 32
diff --git a/llvm/test/Instrumentation/AddressSanitizer/local_alias.ll b/llvm/test/Instrumentation/AddressSanitizer/local_alias.ll
--- a/llvm/test/Instrumentation/AddressSanitizer/local_alias.ll
+++ b/llvm/test/Instrumentation/AddressSanitizer/local_alias.ll
@@ -24,11 +24,11 @@
 ; CHECK-NOINDICATOR-NOT: __odr_asan_gen_a
 ; CHECK-NOALIAS-NOT: private alias
 ; CHECK-INDICATOR: @__odr_asan_gen_a = global i8 0, align 1
-; CHECK-ALIAS: @0 = private alias { [2 x i32], [56 x i8] }, { [2 x i32], [56 x i8] }* @a
+; CHECK-ALIAS: @0 = private alias { [2 x i32], [24 x i8] }, { [2 x i32], [24 x i8] }* @a
 
-; CHECK-ALIAS: @1 = private alias { [2 x i32], [56 x i8] }, { [2 x i32], [56 x i8] }* @b
-; CHECK-ALIAS: @2 = private alias { [2 x i32], [56 x i8] }, { [2 x i32], [56 x i8] }* @c
-; CHECK-ALIAS: @3 = private alias { [2 x i32], [56 x i8] }, { [2 x i32], [56 x i8] }* @d
+; CHECK-ALIAS: @1 = private alias { [2 x i32], [24 x i8] }, { [2 x i32], [24 x i8] }* @b
+; CHECK-ALIAS: @2 = private alias { [2 x i32], [24 x i8] }, { [2 x i32], [24 x i8] }* @c
+; CHECK-ALIAS: @3 = private alias { [2 x i32], [24 x i8] }, { [2 x i32], [24 x i8] }* @d
 
 ; Function Attrs: nounwind sanitize_address uwtable
 define i32 @foo(i32 %M) #0 {
diff --git a/llvm/test/Instrumentation/AddressSanitizer/win-string-literal.ll b/llvm/test/Instrumentation/AddressSanitizer/win-string-literal.ll
--- a/llvm/test/Instrumentation/AddressSanitizer/win-string-literal.ll
+++ b/llvm/test/Instrumentation/AddressSanitizer/win-string-literal.ll
@@ -8,13 +8,13 @@
 ; CHECK: $"??_C@_04JIHMPGLA@asdf?$AA@" = comdat any
 
 ; CHECK: @"??_C@_04JIHMPGLA@asdf?$AA@" =
-; CHECK-SAME: linkonce_odr dso_local constant { [5 x i8], [59 x i8] }
-; CHECK-SAME: { [5 x i8] c"asdf\00", [59 x i8] zeroinitializer }, comdat, align 32
+; CHECK-SAME: linkonce_odr dso_local constant { [5 x i8], [27 x i8] }
+; CHECK-SAME: { [5 x i8] c"asdf\00", [27 x i8] zeroinitializer }, comdat, align 32
 
 ; CHECK: @"__asan_global_??_C@_04JIHMPGLA@asdf?$AA@" =
 ; CHECK-SAME: private global { i64, i64, i64, i64, i64, i64, i64, i64 }
-; CHECK-SAME: { i64 ptrtoint ({ [5 x i8], [59 x i8] }* @"??_C@_04JIHMPGLA@asdf?$AA@" to i64),
-; CHECK-SAME:   i64 5, i64 64, i64 ptrtoint ([17 x i8]* @___asan_gen_.1 to i64),
+; CHECK-SAME: { i64 ptrtoint ({ [5 x i8], [27 x i8] }* @"??_C@_04JIHMPGLA@asdf?$AA@" to i64),
+; CHECK-SAME:   i64 5, i64 32, i64 ptrtoint ([17 x i8]* @___asan_gen_.1 to i64),
 ; CHECK-SAME:   i64 ptrtoint ([8 x i8]* @___asan_gen_ to i64), i64 0,
 ; CHECK-SAME:   i64 ptrtoint ({ [6 x i8]*, i32, i32 }* @___asan_gen_.3 to i64), i64 0 },
 ; CHECK-SAME:   section ".ASAN$GL", comdat($"??_C@_04JIHMPGLA@asdf?$AA@"), align 64