[llvm] r233910 - [support] Add a macro wrapper for alignas and simplify some code.
Benjamin Kramer
benny.kra at googlemail.com
Thu Apr 2 04:32:49 PDT 2015
Author: d0k
Date: Thu Apr 2 06:32:48 2015
New Revision: 233910
URL: http://llvm.org/viewvc/llvm-project?rev=233910&view=rev
Log:
[support] Add a macro wrapper for alignas and simplify some code.
We wrap __attribute((aligned)) for GCC 4.7 and __declspec(align) for
MSVC. The latter behaves weird in some contexts so this should be used
carefully.
Modified:
llvm/trunk/include/llvm/Support/AlignOf.h
llvm/trunk/include/llvm/Support/Compiler.h
llvm/trunk/unittests/Support/AlignOfTest.cpp
Modified: llvm/trunk/include/llvm/Support/AlignOf.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/AlignOf.h?rev=233910&r1=233909&r2=233910&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/AlignOf.h (original)
+++ llvm/trunk/include/llvm/Support/AlignOf.h Thu Apr 2 06:32:48 2015
@@ -70,38 +70,11 @@ inline unsigned alignOf() { return Align
// MSVC requires special handling here.
#ifndef _MSC_VER
-#if __has_feature(cxx_alignas)
template<std::size_t Alignment, std::size_t Size>
struct AlignedCharArray {
- alignas(Alignment) char buffer[Size];
+ LLVM_ALIGNAS(Alignment) char buffer[Size];
};
-#elif defined(__GNUC__) || defined(__IBM_ATTRIBUTES)
-/// \brief Create a type with an aligned char buffer.
-template<std::size_t Alignment, std::size_t Size>
-struct AlignedCharArray;
-
-#define LLVM_ALIGNEDCHARARRAY_TEMPLATE_ALIGNMENT(x) \
- template<std::size_t Size> \
- struct AlignedCharArray<x, Size> { \
- __attribute__((aligned(x))) char buffer[Size]; \
- };
-
-LLVM_ALIGNEDCHARARRAY_TEMPLATE_ALIGNMENT(1)
-LLVM_ALIGNEDCHARARRAY_TEMPLATE_ALIGNMENT(2)
-LLVM_ALIGNEDCHARARRAY_TEMPLATE_ALIGNMENT(4)
-LLVM_ALIGNEDCHARARRAY_TEMPLATE_ALIGNMENT(8)
-LLVM_ALIGNEDCHARARRAY_TEMPLATE_ALIGNMENT(16)
-LLVM_ALIGNEDCHARARRAY_TEMPLATE_ALIGNMENT(32)
-LLVM_ALIGNEDCHARARRAY_TEMPLATE_ALIGNMENT(64)
-LLVM_ALIGNEDCHARARRAY_TEMPLATE_ALIGNMENT(128)
-
-#undef LLVM_ALIGNEDCHARARRAY_TEMPLATE_ALIGNMENT
-
-#else
-# error No supported align as directive.
-#endif
-
#else // _MSC_VER
/// \brief Create a type with an aligned char buffer.
Modified: llvm/trunk/include/llvm/Support/Compiler.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/Compiler.h?rev=233910&r1=233909&r2=233910&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/Compiler.h (original)
+++ llvm/trunk/include/llvm/Support/Compiler.h Thu Apr 2 06:32:48 2015
@@ -281,6 +281,20 @@
# define LLVM_ASSUME_ALIGNED(p, a) (p)
#endif
+/// \macro LLVM_ALIGNAS
+/// \brief Used to specify a minimum alignment for a structure or variable. The
+/// alignment must be a constant integer.
+///
+/// Note that __declspec(align) has special quirks, it's not legal to pass a
+/// structure with __declspec(align) as a formal parameter.
+#ifdef _MSC_VER
+# define LLVM_ALIGNAS(x) __declspec(align(x))
+#elif __GNUC__ && !__has_feature(cxx_alignas) && !LLVM_GNUC_PREREQ(4, 8, 0)
+# define LLVM_ALIGNAS(x) __attribute__((aligned(x)))
+#else
+# define LLVM_ALIGNAS(x) alignas(x)
+#endif
+
/// \macro LLVM_FUNCTION_NAME
/// \brief Expands to __func__ on compilers which support it. Otherwise,
/// expands to a compiler-dependent replacement.
Modified: llvm/trunk/unittests/Support/AlignOfTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/Support/AlignOfTest.cpp?rev=233910&r1=233909&r2=233910&view=diff
==============================================================================
--- llvm/trunk/unittests/Support/AlignOfTest.cpp (original)
+++ llvm/trunk/unittests/Support/AlignOfTest.cpp Thu Apr 2 06:32:48 2015
@@ -39,24 +39,10 @@ namespace {
#endif
// Define some fixed alignment types to use in these tests.
-#if __has_feature(cxx_alignas)
-struct alignas(1) A1 { };
-struct alignas(2) A2 { };
-struct alignas(4) A4 { };
-struct alignas(8) A8 { };
-#elif defined(__GNUC__)
-struct A1 { } __attribute__((aligned(1)));
-struct A2 { } __attribute__((aligned(2)));
-struct A4 { } __attribute__((aligned(4)));
-struct A8 { } __attribute__((aligned(8)));
-#elif defined(_MSC_VER)
-__declspec(align(1)) struct A1 { };
-__declspec(align(2)) struct A2 { };
-__declspec(align(4)) struct A4 { };
-__declspec(align(8)) struct A8 { };
-#else
-# error No supported align as directive.
-#endif
+struct LLVM_ALIGNAS(1) A1 {};
+struct LLVM_ALIGNAS(2) A2 {};
+struct LLVM_ALIGNAS(4) A4 {};
+struct LLVM_ALIGNAS(8) A8 {};
struct S1 {};
struct S2 { char a; };
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