Index: cfe/trunk/lib/Basic/Targets.cpp
===================================================================
--- cfe/trunk/lib/Basic/Targets.cpp
+++ cfe/trunk/lib/Basic/Targets.cpp
@@ -3640,8 +3640,9 @@
     if (!DarwinTargetInfo<X86_32TargetInfo>::handleTargetFeatures(Features,
                                                                   Diags))
       return false;
-    // Now that we know if we have AVX, we can decide how to align vectors.
-    MaxVectorAlign = hasFeature("avx") ? 256 : 128;
+    // We now know the features we have: we can decide how to align vectors.
+    MaxVectorAlign =
+        hasFeature("avx512f") ? 512 : hasFeature("avx") ? 256 : 128;
     return true;
   }
 };
@@ -4006,8 +4007,9 @@
     if (!DarwinTargetInfo<X86_64TargetInfo>::handleTargetFeatures(Features,
                                                                   Diags))
       return false;
-    // Now that we know if we have AVX, we can decide how to align vectors.
-    MaxVectorAlign = hasFeature("avx") ? 256 : 128;
+    // We now know the features we have: we can decide how to align vectors.
+    MaxVectorAlign =
+        hasFeature("avx512f") ? 512 : hasFeature("avx") ? 256 : 128;
     return true;
   }
 };
Index: cfe/trunk/test/CodeGen/vector-alignment.c
===================================================================
--- cfe/trunk/test/CodeGen/vector-alignment.c
+++ cfe/trunk/test/CodeGen/vector-alignment.c
@@ -6,6 +6,10 @@
 // RUN:  -emit-llvm -o - %s | FileCheck %s --check-prefix=ALL --check-prefix=AVX
 // RUN: %clang_cc1 -w -triple   i386-apple-darwin10 -target-feature +avx \
 // RUN:  -emit-llvm -o - %s | FileCheck %s --check-prefix=ALL --check-prefix=AVX
+// RUN: %clang_cc1 -w -triple x86_64-apple-darwin10 -target-feature +avx512f \
+// RUN:  -emit-llvm -o - %s | FileCheck %s --check-prefix=ALL --check-prefix=AVX512
+// RUN: %clang_cc1 -w -triple   i386-apple-darwin10 -target-feature +avx512f \
+// RUN:  -emit-llvm -o - %s | FileCheck %s --check-prefix=ALL --check-prefix=AVX512
 // rdar://11759609
 
 // At or below target max alignment with no aligned attribute should align based
@@ -13,18 +17,22 @@
 double __attribute__((vector_size(16))) v1;
 // SSE: @v1 {{.*}}, align 16
 // AVX: @v1 {{.*}}, align 16
+// AVX512: @v1 {{.*}}, align 16
 double __attribute__((vector_size(32))) v2;
 // SSE: @v2 {{.*}}, align 16
 // AVX: @v2 {{.*}}, align 32
+// AVX512: @v2 {{.*}}, align 32
 
 // Alignment above target max alignment with no aligned attribute should align
 // based on the target max.
 double __attribute__((vector_size(64))) v3;
 // SSE: @v3 {{.*}}, align 16
 // AVX: @v3 {{.*}}, align 32
+// AVX512: @v3 {{.*}}, align 64
 double __attribute__((vector_size(1024))) v4;
 // SSE: @v4 {{.*}}, align 16
 // AVX: @v4 {{.*}}, align 32
+// AVX512: @v4 {{.*}}, align 64
 
 // Aliged attribute should always override.
 double __attribute__((vector_size(16), aligned(16))) v5;
@@ -40,9 +48,11 @@
 double __attribute__((vector_size(24))) v9;
 // SSE: @v9 {{.*}}, align 16
 // AVX: @v9 {{.*}}, align 32
+// AVX512: @v9 {{.*}}, align 32
 double __attribute__((vector_size(40))) v10;
 // SSE: @v10 {{.*}}, align 16
 // AVX: @v10 {{.*}}, align 32
+// AVX512: @v10 {{.*}}, align 64
 
 // Check non-power of 2 widths with aligned attribute.
 double __attribute__((vector_size(24), aligned(64))) v11;