Index: clang/lib/Basic/Targets/PPC.h
===================================================================
--- clang/lib/Basic/Targets/PPC.h
+++ clang/lib/Basic/Targets/PPC.h
@@ -370,7 +370,6 @@
       SizeType = UnsignedLong;
       PtrDiffType = SignedLong;
       IntPtrType = SignedLong;
-      SuitableAlign = 64;
       LongDoubleWidth = 64;
       LongDoubleAlign = DoubleAlign = 32;
       LongDoubleFormat = &llvm::APFloat::IEEEdouble();
@@ -409,7 +408,6 @@
     if (Triple.isOSAIX()) {
       // TODO: Set appropriate ABI for AIX platform.
       DataLayout = "E-m:a-i64:64-n32:64";
-      SuitableAlign = 64;
       LongDoubleWidth = 64;
       LongDoubleAlign = DoubleAlign = 32;
       LongDoubleFormat = &llvm::APFloat::IEEEdouble();
Index: clang/test/CodeGen/aix_alloca_align.c
===================================================================
--- /dev/null
+++ clang/test/CodeGen/aix_alloca_align.c
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -triple=powerpc-ibm-aix-xcoff -S -emit-llvm < %s | \
+// RUN:   FileCheck -check-prefix 32BIT %s
+
+// RUN: %clang_cc1 -triple=powerpc64-ibm-aix-xcoff -S -emit-llvm < %s | \
+// RUN:   FileCheck -check-prefix 64BIT %s
+
+typedef long unsigned int size_t;
+extern void *alloca(size_t __size) __attribute__((__nothrow__));
+
+void foo() {
+  char *ptr1 = (char *)alloca(sizeof(char) * 9);
+}
+
+// 32BIT: %0 = alloca i8, i32 9, align 16
+// 64BIT: %0 = alloca i8, i64 9, align 16