Add additional comments

1 files changed, 24 insertions, 22 deletions

diff --git a/config.h b/config.h
index 17271630..eccba009 100644
--- a/config.h
+++ b/config.h
@@ -68,6 +68,30 @@
 # define CRYPTOPP_DISABLE_ASM 1

 #endif

 

+// Some Clang and SunCC cannot handle mixed asm with positional arguments,

+// where the body is Intel style with no prefix and the templates are

+// AT&T style. Define this is the Makefile misdetects the configuration.

+// Also see https://bugs.llvm.org/show_bug.cgi?id=39895 .

+// #define CRYPTOPP_DISABLE_MIXED_ASM 1

+

+// Several compilers discard SIMD code that loads unaligned data. The symptom

+// is often self test failures and UBsan findings for unaligned loads. For

+// example, Power7 can load unaligned data using vec_vsx_ld but some versions

+// of GCC and Clang require 16-byte aligned data when using the builtin.

+// It is not limited to SSE and PowerPC code. Define this to disable

+// Crypto++ code that uses potentially problematic builtins or intrinsics.

+// Also see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88234 and

+// https://bugs.llvm.org/show_bug.cgi?id=39704

+// #define CRYPTOPP_BUGGY_SIMD_LOAD_AND_STORE 1

+

+// This list will probably grow over time as more compilers are identified.

+#if defined(CRYPTOPP_BUGGY_SIMD_LOAD_AND_STORE)

+# define CRYPTOPP_DISABLE_LEA_SIMD 1

+# define CRYPTOPP_DISABLE_SIMON_SIMD 1

+# define CRYPTOPP_DISABLE_SPECK_SIMD 1

+# define CRYPTOPP_DISABLE_SM4_SIMD 1

+#endif

+

 // Define CRYPTOPP_NO_CXX11 to avoid C++11 related features shown at the

 // end of this file. Some compilers and standard C++ headers advertise C++11

 // but they are really just C++03 with some additional C++11 headers and

@@ -291,28 +315,6 @@ const lword LWORD_MAX = W64LIT(0xffffffffffffffff);
 	#define CRYPTOPP_GCC_DIAGNOSTIC_AVAILABLE 1

 #endif

 

-// Some Clang and SunCC cannot handle mixed asm with positional arguments,

-// where the body is Intel style with no prefix and the templates are

-// AT&T style. Define this is the Makefile misdetects the configuration.

-// Also see https://bugs.llvm.org/show_bug.cgi?id=39895 .

-// #define CRYPTOPP_DISABLE_MIXED_ASM 1

-

-// Several compilers discard SIMD code that loads unaligned data. The symptom

-// is often self test failures and UBsan findings of unaligned loads. For

-// example, Power7 can load unaligned data using vec_vsx_ld but some versions

-// of GCC and Clang require 16-byte aligned arrays when using the builtin

-// function. It is not limited to SSE and PowerPC code. Define this to disable

-// Crypto++ code that uses potentially problematic builtins or intrinsics.

-// #define CRYPTOPP_BUGGY_SIMD_LOAD_AND_STORE 1

-

-// This list will probably grow over time as more compilers are identified.

-#if defined(CRYPTOPP_BUGGY_SIMD_LOAD_AND_STORE)

-# define CRYPTOPP_DISABLE_LEA_SIMD 1

-# define CRYPTOPP_DISABLE_SIMON_SIMD 1

-# define CRYPTOPP_DISABLE_SPECK_SIMD 1

-# define CRYPTOPP_DISABLE_SM4_SIMD 1

-#endif

-

 // define hword, word, and dword. these are used for multiprecision integer arithmetic

 // Intel compiler won't have _umul128 until version 10.0. See http://softwarecommunity.intel.com/isn/Community/en-US/forums/thread/30231625.aspx

 #if (defined(_MSC_VER) && (!defined(__INTEL_COMPILER) || __INTEL_COMPILER >= 1000) && (defined(_M_X64) || defined(_M_IA64))) || (defined(__DECCXX) && defined(__alpha__)) || (defined(__INTEL_COMPILER) && defined(__x86_64__)) || (defined(__SUNPRO_CC) && defined(__x86_64__))