[PATCH] Introduce __BIGGEST_ALIGNMENT__ macro
mats petersson
mats at planetcatfish.com
Sat Dec 13 09:51:27 PST 2014
This is my first attempt for a patch to Clang, so please accept my
apologies for any misconduct with regards to formatting, styling,
content, culture, etc - and I hope that gmail doesn't munge the
patch...
The idea for this came about when at work (ARM) we discussed some code
that had accidentally aligned it's sub-allocated block to 4 bytes for
a 64-bit type, and got a unaligned access trap. So "how do you know",
and someone found __BIGGEST_ALIGNMENT__ in gcc - but not available for
Clang. So I thought I could add it, to make it a little more
consistent between compilers...
--
Mats
Add a predefined macro reflecting the largest alignment required by
the archiecture, in bytes. This is useful for allocator designs that
need to know the system alignment requirements. It reflects the
TargetInfo.SuitableAlignment, converted to bytes (using CharWidth).
---
lib/Frontend/InitPreprocessor.cpp | 4 ++++
test/Preprocessor/init.c | 33 +++++++++++++++++++++++++++++++++
2 files changed, 37 insertions(+), 0 deletions(-)
diff --git a/lib/Frontend/InitPreprocessor.cpp
b/lib/Frontend/InitPreprocessor.cpp
index f4241a9..896277a 100644
--- a/lib/Frontend/InitPreprocessor.cpp
+++ b/lib/Frontend/InitPreprocessor.cpp
@@ -710,6 +710,10 @@ static void InitializePredefinedMacros(const
TargetInfo &TI,
Builder.defineMacro("__POINTER_WIDTH__",
Twine((int)TI.getPointerWidth(0)));
+ // Define __BIGGEST_ALIGNMENT__ to be compatible with gcc.
+ Builder.defineMacro("__BIGGEST_ALIGNMENT__",
+ Twine(TI.getSuitableAlign() / TI.getCharWidth()) );
+
if (!LangOpts.CharIsSigned)
Builder.defineMacro("__CHAR_UNSIGNED__");
diff --git a/test/Preprocessor/init.c b/test/Preprocessor/init.c
index 4f32114..924aa5b 100644
--- a/test/Preprocessor/init.c
+++ b/test/Preprocessor/init.c
@@ -241,6 +241,7 @@
// AARCH64:#define __ARM_ARCH 8
// AARCH64:#define __ARM_ARCH_ISA_A64 1
// AARCH64-NOT:#define __ARM_BIG_ENDIAN 1
+// AARCH64:#define __BIGGEST_ALIGNMENT__ 8
// AARCH64:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// AARCH64:#define __CHAR16_TYPE__ unsigned short
// AARCH64:#define __CHAR32_TYPE__ unsigned int
@@ -431,6 +432,7 @@
// AARCH64-BE:#define __ARM_ARCH 8
// AARCH64-BE:#define __ARM_ARCH_ISA_A64 1
// AARCH64-BE:#define __ARM_BIG_ENDIAN 1
+// AARCH64-BE:#define __BIGGEST_ALIGNMENT__ 8
// AARCH64-BE:#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
// AARCH64-BE:#define __CHAR16_TYPE__ unsigned short
// AARCH64-BE:#define __CHAR32_TYPE__ unsigned int
@@ -621,6 +623,7 @@
// AARCH64-NETBSD:#define __ARM_ARCH 8
// AARCH64-NETBSD:#define __ARM_ARCH_ISA_A64 1
// AARCH64-NETBSD-NOT:#define __ARM_BIG_ENDIAN 1
+// AARCH64-NETBSD:#define __BIGGEST_ALIGNMENT__ 8
// AARCH64-NETBSD:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// AARCH64-NETBSD:#define __CHAR16_TYPE__ unsigned short
// AARCH64-NETBSD:#define __CHAR32_TYPE__ unsigned int
@@ -812,6 +815,7 @@
// AARCH64-FREEBSD:#define __ARM_ARCH 8
// AARCH64-FREEBSD:#define __ARM_ARCH_ISA_A64 1
// AARCH64-FREEBSD-NOT:#define __ARM_BIG_ENDIAN 1
+// AARCH64-FREEBSD:#define __BIGGEST_ALIGNMENT__ 8
// AARCH64-FREEBSD:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// AARCH64-FREEBSD:#define __CHAR16_TYPE__ unsigned short
// AARCH64-FREEBSD:#define __CHAR32_TYPE__ unsigned int
@@ -1003,6 +1007,7 @@
// ARM:#define __ARMEL__ 1
// ARM:#define __ARM_ARCH_6J__ 1
// ARM-NOT:#define __ARM_BIG_ENDIAN 1
+// ARM:#define __BIGGEST_ALIGNMENT__ 8
// ARM:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// ARM:#define __CHAR16_TYPE__ unsigned short
// ARM:#define __CHAR32_TYPE__ unsigned int
@@ -1193,6 +1198,7 @@
// ARM-BE-NOT:#define __ARMEL__ 1
// ARM-BE:#define __ARM_ARCH_6J__ 1
// ARM-BE:#define __ARM_BIG_ENDIAN 1
+// ARM-BE:#define __BIGGEST_ALIGNMENT__ 8
// ARM-BE:#define __BIG_ENDIAN__ 1
// ARM-BE:#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
// ARM-BE:#define __CHAR16_TYPE__ unsigned short
@@ -1387,6 +1393,7 @@
// ARMEABISOFTFP:#define __ARM_EABI__ 1
// ARMEABISOFTFP:#define __ARM_PCS 1
// ARMEABISOFTFP-NOT:#define __ARM_PCS_VFP 1
+// ARMEABISOFTFP:#define __BIGGEST_ALIGNMENT__ 8
// ARMEABISOFTFP:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// ARMEABISOFTFP:#define __CHAR16_TYPE__ unsigned short
// ARMEABISOFTFP:#define __CHAR32_TYPE__ unsigned int
@@ -1582,6 +1589,7 @@
// ARMEABIHARDFP:#define __ARM_EABI__ 1
// ARMEABIHARDFP:#define __ARM_PCS 1
// ARMEABIHARDFP:#define __ARM_PCS_VFP 1
+// ARMEABIHARDFP:#define __BIGGEST_ALIGNMENT__ 8
// ARMEABIHARDFP:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// ARMEABIHARDFP:#define __CHAR16_TYPE__ unsigned short
// ARMEABIHARDFP:#define __CHAR32_TYPE__ unsigned int
@@ -1775,6 +1783,7 @@
// ARM-NETBSD:#define __ARM_DWARF_EH__ 1
// ARM-NETBSD:#define __ARM_EABI__ 1
// ARM-NETBSD-NOT:#define __ARM_BIG_ENDIAN 1
+// ARM-NETBSD:#define __BIGGEST_ALIGNMENT__ 8
// ARM-NETBSD:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// ARM-NETBSD:#define __CHAR16_TYPE__ unsigned short
// ARM-NETBSD:#define __CHAR32_TYPE__ unsigned int
@@ -2021,6 +2030,7 @@
// RUN: %clang_cc1 -E -dM -ffreestanding -triple=i386-none-none <
/dev/null | FileCheck -check-prefix I386 %s
//
// I386-NOT:#define _LP64
+// I386:#define __BIGGEST_ALIGNMENT__ 16
// I386:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// I386:#define __CHAR16_TYPE__ unsigned short
// I386:#define __CHAR32_TYPE__ unsigned int
@@ -2207,6 +2217,7 @@
// RUN: %clang_cc1 -E -dM -ffreestanding -triple=i386-pc-linux-gnu
-target-cpu pentium4 < /dev/null | FileCheck -check-prefix I386-LINUX
%s
//
// I386-LINUX-NOT:#define _LP64
+// I386-LINUX:#define __BIGGEST_ALIGNMENT__ 16
// I386-LINUX:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// I386-LINUX:#define __CHAR16_TYPE__ unsigned short
// I386-LINUX:#define __CHAR32_TYPE__ unsigned int
@@ -2393,6 +2404,7 @@
// RUN: %clang_cc1 -E -dM -ffreestanding -triple=i386-netbsd <
/dev/null | FileCheck -check-prefix I386-NETBSD %s
//
// I386-NETBSD-NOT:#define _LP64
+// I386-NETBSD:#define __BIGGEST_ALIGNMENT__ 16
// I386-NETBSD:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// I386-NETBSD:#define __CHAR16_TYPE__ unsigned short
// I386-NETBSD:#define __CHAR32_TYPE__ unsigned int
@@ -2597,6 +2609,7 @@
// MIPS32BE:#define _MIPS_SZINT 32
// MIPS32BE:#define _MIPS_SZLONG 32
// MIPS32BE:#define _MIPS_SZPTR 32
+// MIPS32BE:#define __BIGGEST_ALIGNMENT__ 8
// MIPS32BE:#define __BIG_ENDIAN__ 1
// MIPS32BE:#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
// MIPS32BE:#define __CHAR16_TYPE__ unsigned short
@@ -2805,6 +2818,7 @@
// MIPS32EL:#define _MIPS_SZINT 32
// MIPS32EL:#define _MIPS_SZLONG 32
// MIPS32EL:#define _MIPS_SZPTR 32
+// MIPS32EL:#define __BIGGEST_ALIGNMENT__ 8
// MIPS32EL:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// MIPS32EL:#define __CHAR16_TYPE__ unsigned short
// MIPS32EL:#define __CHAR32_TYPE__ unsigned int
@@ -3010,6 +3024,7 @@
// MIPS64BE:#define _MIPS_SZINT 32
// MIPS64BE:#define _MIPS_SZLONG 64
// MIPS64BE:#define _MIPS_SZPTR 64
+// MIPS64BE:#define __BIGGEST_ALIGNMENT__ 16
// MIPS64BE:#define __BIG_ENDIAN__ 1
// MIPS64BE:#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
// MIPS64BE:#define __CHAR16_TYPE__ unsigned short
@@ -3218,6 +3233,7 @@
// MIPS64EL:#define _MIPS_SZINT 32
// MIPS64EL:#define _MIPS_SZLONG 64
// MIPS64EL:#define _MIPS_SZPTR 64
+// MIPS64EL:#define __BIGGEST_ALIGNMENT__ 16
// MIPS64EL:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// MIPS64EL:#define __CHAR16_TYPE__ unsigned short
// MIPS64EL:#define __CHAR32_TYPE__ unsigned int
@@ -3583,6 +3599,7 @@
//
// MSP430:#define MSP430 1
// MSP430-NOT:#define _LP64
+// MSP430:#define __BIGGEST_ALIGNMENT__ 2
// MSP430:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// MSP430:#define __CHAR16_TYPE__ unsigned short
// MSP430:#define __CHAR32_TYPE__ unsigned int
@@ -3766,6 +3783,7 @@
// RUN: %clang_cc1 -E -dM -ffreestanding -triple=nvptx-none-none <
/dev/null | FileCheck -check-prefix NVPTX32 %s
//
// NVPTX32-NOT:#define _LP64
+// NVPTX32:#define __BIGGEST_ALIGNMENT__ 8
// NVPTX32:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// NVPTX32:#define __CHAR16_TYPE__ unsigned short
// NVPTX32:#define __CHAR32_TYPE__ unsigned int
@@ -3952,6 +3970,7 @@
// RUN: %clang_cc1 -E -dM -ffreestanding -triple=nvptx64-none-none <
/dev/null | FileCheck -check-prefix NVPTX64 %s
//
// NVPTX64:#define _LP64 1
+// NVPTX64:#define __BIGGEST_ALIGNMENT__ 8
// NVPTX64:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// NVPTX64:#define __CHAR16_TYPE__ unsigned short
// NVPTX64:#define __CHAR32_TYPE__ unsigned int
@@ -4143,6 +4162,7 @@
// PPC603E:#define _ARCH_PPCGR 1
// PPC603E:#define _BIG_ENDIAN 1
// PPC603E-NOT:#define _LP64
+// PPC603E:#define __BIGGEST_ALIGNMENT__ 8
// PPC603E:#define __BIG_ENDIAN__ 1
// PPC603E:#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
// PPC603E:#define __CHAR16_TYPE__ unsigned short
@@ -4340,6 +4360,7 @@
// PPC64:#define _ARCH_PWR7 1
// PPC64:#define _BIG_ENDIAN 1
// PPC64:#define _LP64 1
+// PPC64:#define __BIGGEST_ALIGNMENT__ 8
// PPC64:#define __BIG_ENDIAN__ 1
// PPC64:#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
// PPC64:#define __CHAR16_TYPE__ unsigned short
@@ -4542,6 +4563,7 @@
// PPC64LE:#define _CALL_ELF 2
// PPC64LE:#define _LITTLE_ENDIAN 1
// PPC64LE:#define _LP64 1
+// PPC64LE:#define __BIGGEST_ALIGNMENT__ 8
// PPC64LE:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// PPC64LE:#define __CHAR16_TYPE__ unsigned short
// PPC64LE:#define __CHAR32_TYPE__ unsigned int
@@ -4923,6 +4945,7 @@
// PPC64-LINUX:#define _ARCH_PPC64 1
// PPC64-LINUX:#define _BIG_ENDIAN 1
// PPC64-LINUX:#define _LP64 1
+// PPC64-LINUX:#define __BIGGEST_ALIGNMENT__ 8
// PPC64-LINUX:#define __BIG_ENDIAN__ 1
// PPC64-LINUX:#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
// PPC64-LINUX:#define __CHAR16_TYPE__ unsigned short
@@ -5127,6 +5150,7 @@
// PPC:#define _ARCH_PPC 1
// PPC:#define _BIG_ENDIAN 1
// PPC-NOT:#define _LP64
+// PPC:#define __BIGGEST_ALIGNMENT__ 8
// PPC:#define __BIG_ENDIAN__ 1
// PPC:#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
// PPC:#define __CHAR16_TYPE__ unsigned short
@@ -5317,6 +5341,7 @@
// PPC-LINUX:#define _ARCH_PPC 1
// PPC-LINUX:#define _BIG_ENDIAN 1
// PPC-LINUX-NOT:#define _LP64
+// PPC-LINUX:#define __BIGGEST_ALIGNMENT__ 8
// PPC-LINUX:#define __BIG_ENDIAN__ 1
// PPC-LINUX:#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
// PPC-LINUX:#define __CHAR16_TYPE__ unsigned short
@@ -5508,6 +5533,7 @@
//
// PPC-DARWIN:#define _ARCH_PPC 1
// PPC-DARWIN:#define _BIG_ENDIAN 1
+// PPC-DARWIN:#define __BIGGEST_ALIGNMENT__ 16
// PPC-DARWIN:#define __BIG_ENDIAN__ 1
// PPC-DARWIN:#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
// PPC-DARWIN:#define __CHAR16_TYPE__ unsigned short
@@ -5701,6 +5727,7 @@
//
// RUN: %clang_cc1 -E -dM -ffreestanding -triple=s390x-none-none
-fno-signed-char < /dev/null | FileCheck -check-prefix S390X %s
//
+// S390X:#define __BIGGEST_ALIGNMENT__ 8
// S390X:#define __CHAR16_TYPE__ unsigned short
// S390X:#define __CHAR32_TYPE__ unsigned int
// S390X:#define __CHAR_BIT__ 8
@@ -5882,6 +5909,7 @@
// RUN: %clang_cc1 -E -dM -ffreestanding -triple=sparc-none-none <
/dev/null | FileCheck -check-prefix SPARC %s
//
// SPARC-NOT:#define _LP64
+// SPARC:#define __BIGGEST_ALIGNMENT__ 8
// SPARC:#define __BIG_ENDIAN__ 1
// SPARC:#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
// SPARC:#define __CHAR16_TYPE__ unsigned short
@@ -6069,6 +6097,7 @@
// RUN: %clang_cc1 -E -dM -ffreestanding -triple=tce-none-none <
/dev/null | FileCheck -check-prefix TCE %s
//
// TCE-NOT:#define _LP64
+// TCE:#define __BIGGEST_ALIGNMENT__ 4
// TCE:#define __BIG_ENDIAN__ 1
// TCE:#define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
// TCE:#define __CHAR16_TYPE__ unsigned short
@@ -6236,6 +6265,7 @@
//
// X86_64:#define _LP64 1
// X86_64-NOT:#define _LP32 1
+// X86_64:#define __BIGGEST_ALIGNMENT__ 16
// X86_64:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// X86_64:#define __CHAR16_TYPE__ unsigned short
// X86_64:#define __CHAR32_TYPE__ unsigned int
@@ -6437,6 +6467,7 @@
//
// X32:#define _ILP32 1
// X32-NOT:#define _LP64 1
+// X32:#define __BIGGEST_ALIGNMENT__ 16
// X32:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// X32:#define __CHAR16_TYPE__ unsigned short
// X32:#define __CHAR32_TYPE__ unsigned int
@@ -6630,6 +6661,7 @@
// RUN: %clang_cc1 -E -dM -ffreestanding -triple=x86_64-pc-linux-gnu
< /dev/null | FileCheck -check-prefix X86_64-LINUX %s
//
// X86_64-LINUX:#define _LP64 1
+// X86_64-LINUX:#define __BIGGEST_ALIGNMENT__ 16
// X86_64-LINUX:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// X86_64-LINUX:#define __CHAR16_TYPE__ unsigned short
// X86_64-LINUX:#define __CHAR32_TYPE__ unsigned int
@@ -6828,6 +6860,7 @@
// RUN: %clang_cc1 -E -dM -ffreestanding -triple=x86_64-netbsd <
/dev/null | FileCheck -check-prefix X86_64-NETBSD %s
//
// X86_64-NETBSD:#define _LP64 1
+// X86_64-NETBSD:#define __BIGGEST_ALIGNMENT__ 16
// X86_64-NETBSD:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// X86_64-NETBSD:#define __CHAR16_TYPE__ unsigned short
// X86_64-NETBSD:#define __CHAR32_TYPE__ unsigned int
--
1.7.7.6
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