Index: clang/lib/Basic/Targets/X86.cpp
===================================================================
--- clang/lib/Basic/Targets/X86.cpp
+++ clang/lib/Basic/Targets/X86.cpp
@@ -423,6 +423,7 @@
     defineCPUMacros(Builder, "pentiumpro");
     break;
   case CK_Pentium4:
+  case CK_x86_32_sse2:
     defineCPUMacros(Builder, "pentium4");
     break;
   case CK_Yonah:
@@ -1252,6 +1253,7 @@
 
     // Netburst
     case CK_Pentium4:
+    case CK_x86_32_sse2:
     case CK_Prescott:
     case CK_Nocona:
     // Atom
Index: clang/lib/Driver/ToolChains/Arch/X86.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Arch/X86.cpp
+++ clang/lib/Driver/ToolChains/Arch/X86.cpp
@@ -44,7 +44,7 @@
       CPU = llvm::StringSwitch<const char *>(Arch)
                 .Case("IA32", "i386")
                 .Case("SSE", "pentium3")
-                .Case("SSE2", "pentium4")
+                .Case("SSE2", "x86-32-sse2")
                 .Default(nullptr);
     }
     if (CPU == nullptr) {  // 32-bit and 64-bit /arch: flags.
@@ -101,8 +101,10 @@
   case llvm::Triple::Haiku:
     return "i586";
   default:
-    // Fallback to p4.
-    return "pentium4";
+    // Fallback to generic 32-bit CPU with sse2.
+    // FIXME: If we supported mtune this should just be pentium4 with generic
+    // tuning.
+    return "x86-32-sse2";
   }
 }
 
Index: clang/test/Driver/nacl-direct.c
===================================================================
--- clang/test/Driver/nacl-direct.c
+++ clang/test/Driver/nacl-direct.c
@@ -6,7 +6,7 @@
 // RUN:   | FileCheck --check-prefix=CHECK-I686 %s
 // CHECK-I686: {{.*}}clang{{.*}}" "-cc1"
 // CHECK-I686-NOT: "-fno-use-init-array"
-// CHECK-I686: "-target-cpu" "pentium4"
+// CHECK-I686: "-target-cpu" "x86-32-sse2"
 // CHECK-I686: "-resource-dir" "foo"
 // CHECK-I686: "-internal-isystem" "foo{{/|\\\\}}include"
 // CHECK-I686: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}i686-nacl{{/|\\\\}}usr{{/|\\\\}}include"
Index: clang/test/Driver/x86_features.c
===================================================================
--- clang/test/Driver/x86_features.c
+++ clang/test/Driver/x86_features.c
@@ -1,5 +1,5 @@
 // RUN: %clang -target i386-unknown-unknown -### -S %s -msse -msse4 -mno-sse -mno-mmx -msse  2>&1 | FileCheck %s
-// CHECK: "pentium4" "-target-feature" "+sse4.2" "-target-feature" "-mmx" "-target-feature" "+sse"
+// CHECK: "x86-32-sse2" "-target-feature" "+sse4.2" "-target-feature" "-mmx" "-target-feature" "+sse"
 // Note that we filter out all but the last -m(no)sse.
 
 // Test that we don't produce an error with -mieee-fp.
Index: clang/test/Misc/target-invalid-cpu-note.c
===================================================================
--- clang/test/Misc/target-invalid-cpu-note.c
+++ clang/test/Misc/target-invalid-cpu-note.c
@@ -20,7 +20,7 @@
 // X86-SAME: athlon, athlon-tbird, athlon-xp, athlon-mp, athlon-4, k8, athlon64,
 // X86-SAME: athlon-fx, opteron, k8-sse3, athlon64-sse3, opteron-sse3, amdfam10,
 // X86-SAME: barcelona, btver1, btver2, bdver1, bdver2, bdver3, bdver4, znver1, znver2,
-// X86-SAME: x86-64, geode
+// X86-SAME: x86-64, x86-32-sse2, geode
 
 // RUN: not %clang_cc1 -triple x86_64--- -target-cpu not-a-cpu -fsyntax-only %s 2>&1 | FileCheck %s --check-prefix X86_64
 // X86_64: error: unknown target CPU 'not-a-cpu'
Index: llvm/include/llvm/Support/X86TargetParser.h
===================================================================
--- llvm/include/llvm/Support/X86TargetParser.h
+++ llvm/include/llvm/Support/X86TargetParser.h
@@ -119,6 +119,7 @@
   CK_ZNVER1,
   CK_ZNVER2,
   CK_x86_64,
+  CK_x86_32_sse2,
   CK_Geode,
 };
 
Index: llvm/lib/Support/X86TargetParser.cpp
===================================================================
--- llvm/lib/Support/X86TargetParser.cpp
+++ llvm/lib/Support/X86TargetParser.cpp
@@ -370,6 +370,8 @@
   { {"znver2"}, CK_ZNVER2, FEATURE_AVX2, FeaturesZNVER2 },
   // Generic 64-bit processor.
   { {"x86-64"}, CK_x86_64, ~0U, FeaturesX86_64 },
+  // Generic 32-bit processor.
+  { {"x86-32-sse2"}, CK_x86_32_sse2, ~0U, FeaturesPentium4 },
   // Geode processors.
   { {"geode"}, CK_Geode, ~0U, FeaturesGeode },
 };
Index: llvm/lib/Target/X86/X86.td
===================================================================
--- llvm/lib/Target/X86/X86.td
+++ llvm/lib/Target/X86/X86.td
@@ -1294,6 +1294,25 @@
   FeatureInsertVZEROUPPER
 ]>;
 
+// Provide a generic 32-bit sse2 CPU with modern tuning settings. This is the
+// default for 32-bit mode.
+// FIXME: If we supported mtune we could have generic tuning for modern with
+// arch as pentium4.
+def : ProcessorModel<"x86-32-sse2", SandyBridgeModel, [
+  FeatureX87,
+  FeatureCMPXCHG8B,
+  FeatureCMOV,
+  FeatureMMX,
+  FeatureSSE2,
+  FeatureFXSR,
+  FeatureNOPL,
+  FeatureSlow3OpsLEA,
+  FeatureSlowDivide64,
+  FeatureSlowIncDec,
+  FeatureMacroFusion,
+  FeatureInsertVZEROUPPER
+]>;
+
 //===----------------------------------------------------------------------===//
 // Calling Conventions
 //===----------------------------------------------------------------------===//