Fix non-determinism in order of LLVM attributes

We were using array_pod_sort on an array of type 'Attribute', which
wraps a pointer to AttributeImpl. For the most part this didn't matter
because the printing code prints enum attributes in a defined order, but
integer attributes such as 'align' and 'dereferenceable' were not
ordered.

Furthermore, AttributeImpl::operator< was broken for integer attributes.
An integer attribute is a kind and an integer value, and both pieces
need to be compared.

By fixing the comparison operator, we can go back to std::sort, and
things look good now.  This should fix clang arm-swiftcall.c test
failures on Windows.

llvm-svn: 265361

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/unittests/IR/AttributesTest.cpp b/llvm/unittests/IR/AttributesTest.cpp
index ebcb772bc37..9f8013ff181 100644
--- a/llvm/unittests/IR/AttributesTest.cpp
+++ b/llvm/unittests/IR/AttributesTest.cpp
@@ -34,6 +34,15 @@ TEST(Attributes, Uniquing) {
 TEST(Attributes, Ordering) {
   LLVMContext C;
 
+  Attribute Align4 = Attribute::get(C, Attribute::Alignment, 4);
+  Attribute Align5 = Attribute::get(C, Attribute::Alignment, 5);
+  Attribute Deref4 = Attribute::get(C, Attribute::Dereferenceable, 4);
+  Attribute Deref5 = Attribute::get(C, Attribute::Dereferenceable, 5);
+  EXPECT_TRUE(Align4 < Align5);
+  EXPECT_TRUE(Align4 < Deref4);
+  EXPECT_TRUE(Align4 < Deref5);
+  EXPECT_TRUE(Align5 < Deref4);
+
   AttributeSet ASs[] = {
     AttributeSet::get(C, 2, Attribute::ZExt),
     AttributeSet::get(C, 1, Attribute::SExt)