diff --git a/clang/include/clang/Lex/LiteralSupport.h b/clang/include/clang/Lex/LiteralSupport.h
--- a/clang/include/clang/Lex/LiteralSupport.h
+++ b/clang/include/clang/Lex/LiteralSupport.h
@@ -69,8 +69,8 @@
   bool isImaginary : 1;     // 1.0i
   bool isFloat16 : 1;       // 1.0f16
   bool isFloat128 : 1;      // 1.0q
-  uint8_t MicrosoftInteger; // Microsoft suffix extension i8, i16, i32, or i64.
-
+  uint8_t MicrosoftInteger; // Microsoft suffix extension i8, i16, i32, i64, or
+                            // i128.
   bool isFract : 1;         // 1.0hr/r/lr/uhr/ur/ulr
   bool isAccum : 1;         // 1.0hk/k/lk/uhk/uk/ulk
 
diff --git a/clang/lib/AST/StmtPrinter.cpp b/clang/lib/AST/StmtPrinter.cpp
--- a/clang/lib/AST/StmtPrinter.cpp
+++ b/clang/lib/AST/StmtPrinter.cpp
@@ -1168,9 +1168,13 @@
   case BuiltinType::LongLong:  OS << "LL"; break;
   case BuiltinType::ULongLong: OS << "ULL"; break;
   case BuiltinType::Int128:
-    break; // no suffix.
+    if (Context && Context->getLangOpts().MicrosoftExt)
+      OS << "i128";
+    break;
   case BuiltinType::UInt128:
-    break; // no suffix.
+    if (Context && Context->getLangOpts().MicrosoftExt)
+      OS << "ui128";
+    break;
   }
 }
 
diff --git a/clang/lib/Lex/LiteralSupport.cpp b/clang/lib/Lex/LiteralSupport.cpp
--- a/clang/lib/Lex/LiteralSupport.cpp
+++ b/clang/lib/Lex/LiteralSupport.cpp
@@ -849,7 +849,7 @@
     case 'i':
     case 'I':
       if (LangOpts.MicrosoftExt && !isFPConstant) {
-        // Allow i8, i16, i32, and i64. First, look ahead and check if
+        // Allow i8, i16, i32, i64, and i128. First, look ahead and check if
         // suffixes are Microsoft integers and not the imaginary unit.
         uint8_t Bits = 0;
         size_t ToSkip = 0;
@@ -859,7 +859,10 @@
           ToSkip = 2;
           break;
         case '1':
-          if (s[2] == '6') { // i16 suffix
+          if (s[2] == '2' && s[3] == '8') {
+            Bits = 128;
+            ToSkip = 4;
+          } else if (s[2] == '6') { // i16 suffix
             Bits = 16;
             ToSkip = 3;
           }
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -3924,6 +3924,11 @@
 
     // Get the value in the widest-possible width.
     unsigned MaxWidth = Context.getTargetInfo().getIntMaxTWidth();
+    // Microsoft extensions allow a maximal integer greater than `intmax_t` via
+    // the `i128` suffix, creating a 128-bit integeral value with a 64-bit
+    // maximum integer type.
+    if (Literal.MicrosoftInteger)
+      MaxWidth = Literal.MicrosoftInteger;
     llvm::APInt ResultVal(MaxWidth, 0);
 
     if (Literal.GetIntegerValue(ResultVal)) {
diff --git a/clang/test/Lexer/ms-extensions.c b/clang/test/Lexer/ms-extensions.c
--- a/clang/test/Lexer/ms-extensions.c
+++ b/clang/test/Lexer/ms-extensions.c
@@ -23,6 +23,9 @@
 #define USHORT 0xffffui16
 #define UCHAR 0xffui8
 
+#define INT128_MAX  170141183460469231731687303715884105727i128
+#define UINT128_MAX 0xffffffffffffffffffffffffffffffffui128
+
 void a(void) {
 	unsigned long long m = ULLONG_MAX;
 	unsigned int n = UINT;
diff --git a/clang/unittests/AST/StmtPrinterTest.cpp b/clang/unittests/AST/StmtPrinterTest.cpp
--- a/clang/unittests/AST/StmtPrinterTest.cpp
+++ b/clang/unittests/AST/StmtPrinterTest.cpp
@@ -44,7 +44,7 @@
   PrintingPolicy Policy = Context->getPrintingPolicy();
   if (PolicyAdjuster)
     PolicyAdjuster(Policy);
-  S->printPretty(Out, /*Helper*/ nullptr, Policy);
+  S->printPretty(Out, /*Helper*/ nullptr, Policy, 0, "\n", Context);
 }
 
 template <typename Matcher>
@@ -128,13 +128,15 @@
     "  1i8, -1i8, 1ui8, "
     "  1i16, -1i16, 1ui16, "
     "  1i32, -1i32, 1ui32, "
-    "  1i64, -1i64, 1ui64;"
+    "  1i64, -1i64, 1ui64, "
+    "  1i128, -1i128, 1ui128;"
     "}",
     FunctionBodyMatcher("A"),
     "1i8 , -1i8 , 1Ui8 , "
     "1i16 , -1i16 , 1Ui16 , "
     "1 , -1 , 1U , "
-    "1LL , -1LL , 1ULL"));
+    "1LL , -1LL , 1ULL , "
+    "1i128 , -1i128 , 1ui128"));
     // Should be: with semicolon
 }