Index: cfe/trunk/lib/Basic/Targets.cpp
===================================================================
--- cfe/trunk/lib/Basic/Targets.cpp
+++ cfe/trunk/lib/Basic/Targets.cpp
@@ -2239,6 +2239,10 @@
     /// Knights Landing processor.
     CK_KNL,
 
+    /// \name Lakemont
+    /// Lakemont microarchitecture based processors.
+    CK_Lakemont,
+
     /// \name K6
     /// K6 architecture processors.
     //@{
@@ -2343,6 +2347,7 @@
         .Case("skx", CK_SkylakeServer) // Legacy name.
         .Case("cannonlake", CK_Cannonlake)
         .Case("knl", CK_KNL)
+        .Case("lakemont", CK_Lakemont)
         .Case("k6", CK_K6)
         .Case("k6-2", CK_K6_2)
         .Case("k6-3", CK_K6_3)
@@ -2490,6 +2495,7 @@
     case CK_C3_2:
     case CK_Pentium4:
     case CK_Pentium4M:
+    case CK_Lakemont:
     case CK_Prescott:
     case CK_K6:
     case CK_K6_2:
@@ -2588,10 +2594,13 @@
   if (getTriple().getArch() == llvm::Triple::x86_64)
     setFeatureEnabledImpl(Features, "sse2", true);
 
-  // Enable X87 for all X86 processors.
-  setFeatureEnabledImpl(Features, "x87", true);
+  const CPUKind Kind = getCPUKind(CPU);
+
+  // Enable X87 for all X86 processors but Lakemont.
+  if (Kind != CK_Lakemont)
+    setFeatureEnabledImpl(Features, "x87", true);
 
-  switch (getCPUKind(CPU)) {
+  switch (Kind) {
   case CK_Generic:
   case CK_i386:
   case CK_i486:
@@ -2599,6 +2608,7 @@
   case CK_Pentium:
   case CK_i686:
   case CK_PentiumPro:
+  case CK_Lakemont:
     break;
   case CK_PentiumMMX:
   case CK_Pentium2:
@@ -3253,6 +3263,9 @@
   case CK_KNL:
     defineCPUMacros(Builder, "knl");
     break;
+  case CK_Lakemont:
+    Builder.defineMacro("__tune_lakemont__");
+    break;
   case CK_K6_2:
     Builder.defineMacro("__k6_2__");
     Builder.defineMacro("__tune_k6_2__");
Index: cfe/trunk/test/CodeGen/attr-target-x86.c
===================================================================
--- cfe/trunk/test/CodeGen/attr-target-x86.c
+++ cfe/trunk/test/CodeGen/attr-target-x86.c
@@ -18,6 +18,8 @@
 
 int __attribute__((target("no-mmx"))) qq(int a) { return 40; }
 
+int __attribute__((target("arch=lakemont"))) lake(int a) { return 4; }
+
 // Check that we emit the additional subtarget and cpu features for foo and not for baz or bar.
 // CHECK: baz{{.*}} #0
 // CHECK: foo{{.*}} #1
@@ -31,9 +33,11 @@
 // CHECK: qux{{.*}} #1
 // CHECK: qax{{.*}} #4
 // CHECK: qq{{.*}} #5
+// CHECK: lake{{.*}} #6
 // CHECK: #0 = {{.*}}"target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87"
 // CHECK: #1 = {{.*}}"target-cpu"="ivybridge" "target-features"="+aes,+avx,+cx16,+f16c,+fsgsbase,+fxsr,+mmx,+pclmul,+popcnt,+rdrnd,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3,+x87,+xsave,+xsaveopt"
 // CHECK: #2 = {{.*}}"target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+x87,-aes,-avx,-avx2,-avx512bw,-avx512cd,-avx512dq,-avx512er,-avx512f,-avx512ifma,-avx512pf,-avx512vbmi,-avx512vl,-f16c,-fma,-fma4,-pclmul,-sha,-sse2,-sse3,-sse4.1,-sse4.2,-sse4a,-ssse3,-xop,-xsave,-xsaveopt"
 // CHECK: #3 = {{.*}}"target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+popcnt,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3,+x87"
 // CHECK: #4 = {{.*}}"target-cpu"="ivybridge" "target-features"="+avx,+cx16,+f16c,+fsgsbase,+fxsr,+mmx,+pclmul,+popcnt,+rdrnd,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3,+x87,+xsave,+xsaveopt,-aes"
 // CHECK: #5 = {{.*}}"target-cpu"="x86-64" "target-features"="+fxsr,+sse,+sse2,+x87,-3dnow,-3dnowa,-mmx"
+// CHECK: #6 = {{.*}}"target-cpu"="lakemont" "target-features"="+mmx,+sse,+sse2"
Index: cfe/trunk/test/Preprocessor/predefined-arch-macros.c
===================================================================
--- cfe/trunk/test/Preprocessor/predefined-arch-macros.c
+++ cfe/trunk/test/Preprocessor/predefined-arch-macros.c
@@ -1004,6 +1004,18 @@
 // CHECK_SLM_M64: #define __x86_64 1
 // CHECK_SLM_M64: #define __x86_64__ 1
 //
+// RUN: %clang -march=lakemont -m32 -E -dM %s -o - 2>&1 \
+// RUN:     -target i386-unknown-linux \
+// RUN:   | FileCheck %s -check-prefix=CHECK_LMT_M32
+// CHECK_LMT_M32: #define __i386 1
+// CHECK_LMT_M32: #define __i386__ 1
+// CHECK_LMT_M32: #define __tune_lakemont__ 1
+// CHECK_LMT_M32: #define i386 1
+// RUN: not %clang -march=lakemont -m64 -E -dM %s -o - 2>&1 \
+// RUN:     -target i386-unknown-linux \
+// RUN:   | FileCheck %s -check-prefix=CHECK_LMT_M64
+// CHECK_LMT_M64: error:
+//
 // RUN: %clang -march=geode -m32 -E -dM %s -o - 2>&1 \
 // RUN:     -target i386-unknown-linux \
 // RUN:   | FileCheck -match-full-lines %s -check-prefix=CHECK_GEODE_M32