Teach DataLayout that alignments on basic types must be powers of two.

Fixes assertion failures/crashes on bad datalayout specifications.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230940 91177308-0d34-0410-b5e6-96231b3b80d8

lib/IR/DataLayout.cpp

@@ -405,6 +405,10 @@ DataLayout::setAlignment(AlignTypeEnum align_type, unsigned abi_align,
     report_fatal_error("Invalid ABI alignment, must be a 16bit integer");
   if (!isUInt<16>(pref_align))
     report_fatal_error("Invalid preferred alignment, must be a 16bit integer");
+  if (abi_align != 0 && !isPowerOf2_64(abi_align))
+    report_fatal_error("Invalid ABI alignment, must be a power of 2");
+  if (pref_align != 0 && !isPowerOf2_64(pref_align))
+    report_fatal_error("Invalid preferred alignment, must be a power of 2");
 
   if (pref_align < abi_align)
     report_fatal_error(

test/Assembler/invalid-datalayout23.ll

@@ -0,0 +1,6 @@
+; RUN: not llvm-as < %s 2>&1 | FileCheck %s
+
+target datalayout = "i32:24:32"
+
+; CHECK: Invalid ABI alignment, must be a power of 2
+

test/Assembler/invalid-datalayout24.ll

@@ -0,0 +1,6 @@
+; RUN: not llvm-as < %s 2>&1 | FileCheck %s
+
+target datalayout = "i32:32:24"
+
+; CHECK: Invalid preferred alignment, must be a power of 2
+