aaron.ballman created this revision.
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Herald added a subscriber: dschuff.
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Herald added a project: clang.
Part of the `_BitInt` feature in C2x
(http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2763.pdf) is a new macro in
limits.h named `BITINT_MAXWIDTH` that can be used to determine the maximum
width of a bit-precise integer type. This macro must expand to a value that is
at least as large as `ULLONG_WIDTH`.
This adds an implementation-defined macro named `__BITINT_MAXWIDTH__` to
specify that value, which is used by limits.h for the standard macro. This
gives us a migration path in the future should a target ever need to support
something different than `llvm::IntegerType::MAX_INT_BITS`.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D117238
Files:
clang/lib/Frontend/InitPreprocessor.cpp
clang/lib/Headers/limits.h
clang/lib/Sema/SemaType.cpp
clang/test/Headers/limits.cpp
clang/test/Preprocessor/init-aarch64.c
clang/test/Preprocessor/init.c
Index: clang/test/Preprocessor/init.c
===================================================================
--- clang/test/Preprocessor/init.c
+++ clang/test/Preprocessor/init.c
@@ -1520,6 +1520,7 @@
// WEBASSEMBLY-NEXT:#define __ATOMIC_RELEASE 3
// WEBASSEMBLY-NEXT:#define __ATOMIC_SEQ_CST 5
// WEBASSEMBLY-NEXT:#define __BIGGEST_ALIGNMENT__ 16
+// WEBASSEMBLY-NEXT:#define __BITINT_MAXWIDTH__ 8388608
// WEBASSEMBLY-NEXT:#define __BOOL_WIDTH__ 8
// WEBASSEMBLY-NEXT:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// WEBASSEMBLY-NEXT:#define __CHAR16_TYPE__ unsigned short
Index: clang/test/Preprocessor/init-aarch64.c
===================================================================
--- clang/test/Preprocessor/init-aarch64.c
+++ clang/test/Preprocessor/init-aarch64.c
@@ -40,6 +40,7 @@
// AARCH64-NEXT: #define __ATOMIC_SEQ_CST 5
// AARCH64: #define __BIGGEST_ALIGNMENT__ 16
// AARCH64_BE-NEXT: #define __BIG_ENDIAN__ 1
+// AARCH64-NEXT: #define __BITINT_MAXWIDTH__ 8388608
// AARCH64-NEXT: #define __BOOL_WIDTH__ 8
// AARCH64_BE-NEXT: #define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
// AARCH64_LE-NEXT: #define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
Index: clang/test/Headers/limits.cpp
===================================================================
--- clang/test/Headers/limits.cpp
+++ clang/test/Headers/limits.cpp
@@ -74,8 +74,11 @@
_Static_assert(ULLONG_WIDTH / CHAR_BIT == sizeof(unsigned long long));
_Static_assert(LLONG_WIDTH == ULLONG_WIDTH);
_Static_assert(LLONG_WIDTH / CHAR_BIT == sizeof(signed long long));
+
+_Static_assert(BITINT_MAXWIDTH >= ULLONG_WIDTH);
#else
/* None of these are defined. */
int BOOL_WIDTH, CHAR_WIDTH, SCHAR_WIDTH, UCHAR_WIDTH, USHRT_WIDTH, SHRT_WIDTH,
- UINT_WIDTH, INT_WIDTH, ULONG_WIDTH, LONG_WIDTH, ULLONG_WIDTH, LLONG_WIDTH;
+ UINT_WIDTH, INT_WIDTH, ULONG_WIDTH, LONG_WIDTH, ULLONG_WIDTH, LLONG_WIDTH,
+ BITINT_MAXWIDTH;
#endif
Index: clang/lib/Sema/SemaType.cpp
===================================================================
--- clang/lib/Sema/SemaType.cpp
+++ clang/lib/Sema/SemaType.cpp
@@ -2267,6 +2267,10 @@
return QualType();
}
+ // The max size of a _BitInt is exposed to the user via the
+ // __BITINT_MAXWIDTH__ macro from InitPreprocessor.cpp. If someday a target
+ // needs to pick a different max value, be sure to update
+ // InitializePredefinedMacros() as well.
if (NumBits > llvm::IntegerType::MAX_INT_BITS) {
Diag(Loc, diag::err_bit_int_max_size)
<< IsUnsigned << llvm::IntegerType::MAX_INT_BITS;
Index: clang/lib/Headers/limits.h
===================================================================
--- clang/lib/Headers/limits.h
+++ clang/lib/Headers/limits.h
@@ -78,6 +78,8 @@
#define LONG_WIDTH __LONG_WIDTH__
#define ULLONG_WIDTH __LLONG_WIDTH__
#define LLONG_WIDTH __LLONG_WIDTH__
+
+#define BITINT_MAXWIDTH __BITINT_MAXWIDTH__
#endif
#ifdef __CHAR_UNSIGNED__ /* -funsigned-char */
Index: clang/lib/Frontend/InitPreprocessor.cpp
===================================================================
--- clang/lib/Frontend/InitPreprocessor.cpp
+++ clang/lib/Frontend/InitPreprocessor.cpp
@@ -25,6 +25,7 @@
#include "clang/Serialization/ASTReader.h"
#include "llvm/ADT/APFloat.h"
#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
using namespace clang;
static bool MacroBodyEndsInBackslash(StringRef MacroBody) {
@@ -914,6 +915,12 @@
Builder.defineMacro("__LONG_WIDTH__", Twine(TI.getLongWidth()));
Builder.defineMacro("__LLONG_WIDTH__", Twine(TI.getLongLongWidth()));
+ // The max size of a _BitInt is limited in SemaType.cpp to this value. If
+ // someday a target needs to pick a different value for this macro, be sure
+ // to update Sema::BuildBitIntType() as well.
+ Builder.defineMacro("__BITINT_MAXWIDTH__",
+ Twine(llvm::IntegerType::MAX_INT_BITS));
+
DefineTypeSize("__SCHAR_MAX__", TargetInfo::SignedChar, TI, Builder);
DefineTypeSize("__SHRT_MAX__", TargetInfo::SignedShort, TI, Builder);
DefineTypeSize("__INT_MAX__", TargetInfo::SignedInt, TI, Builder);
Index: clang/test/Preprocessor/init.c
===================================================================
--- clang/test/Preprocessor/init.c
+++ clang/test/Preprocessor/init.c
@@ -1520,6 +1520,7 @@
// WEBASSEMBLY-NEXT:#define __ATOMIC_RELEASE 3
// WEBASSEMBLY-NEXT:#define __ATOMIC_SEQ_CST 5
// WEBASSEMBLY-NEXT:#define __BIGGEST_ALIGNMENT__ 16
+// WEBASSEMBLY-NEXT:#define __BITINT_MAXWIDTH__ 8388608
// WEBASSEMBLY-NEXT:#define __BOOL_WIDTH__ 8
// WEBASSEMBLY-NEXT:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
// WEBASSEMBLY-NEXT:#define __CHAR16_TYPE__ unsigned short
Index: clang/test/Preprocessor/init-aarch64.c
===================================================================
--- clang/test/Preprocessor/init-aarch64.c
+++ clang/test/Preprocessor/init-aarch64.c
@@ -40,6 +40,7 @@
// AARCH64-NEXT: #define __ATOMIC_SEQ_CST 5
// AARCH64: #define __BIGGEST_ALIGNMENT__ 16
// AARCH64_BE-NEXT: #define __BIG_ENDIAN__ 1
+// AARCH64-NEXT: #define __BITINT_MAXWIDTH__ 8388608
// AARCH64-NEXT: #define __BOOL_WIDTH__ 8
// AARCH64_BE-NEXT: #define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
// AARCH64_LE-NEXT: #define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
Index: clang/test/Headers/limits.cpp
===================================================================
--- clang/test/Headers/limits.cpp
+++ clang/test/Headers/limits.cpp
@@ -74,8 +74,11 @@
_Static_assert(ULLONG_WIDTH / CHAR_BIT == sizeof(unsigned long long));
_Static_assert(LLONG_WIDTH == ULLONG_WIDTH);
_Static_assert(LLONG_WIDTH / CHAR_BIT == sizeof(signed long long));
+
+_Static_assert(BITINT_MAXWIDTH >= ULLONG_WIDTH);
#else
/* None of these are defined. */
int BOOL_WIDTH, CHAR_WIDTH, SCHAR_WIDTH, UCHAR_WIDTH, USHRT_WIDTH, SHRT_WIDTH,
- UINT_WIDTH, INT_WIDTH, ULONG_WIDTH, LONG_WIDTH, ULLONG_WIDTH, LLONG_WIDTH;
+ UINT_WIDTH, INT_WIDTH, ULONG_WIDTH, LONG_WIDTH, ULLONG_WIDTH, LLONG_WIDTH,
+ BITINT_MAXWIDTH;
#endif
Index: clang/lib/Sema/SemaType.cpp
===================================================================
--- clang/lib/Sema/SemaType.cpp
+++ clang/lib/Sema/SemaType.cpp
@@ -2267,6 +2267,10 @@
return QualType();
}
+ // The max size of a _BitInt is exposed to the user via the
+ // __BITINT_MAXWIDTH__ macro from InitPreprocessor.cpp. If someday a target
+ // needs to pick a different max value, be sure to update
+ // InitializePredefinedMacros() as well.
if (NumBits > llvm::IntegerType::MAX_INT_BITS) {
Diag(Loc, diag::err_bit_int_max_size)
<< IsUnsigned << llvm::IntegerType::MAX_INT_BITS;
Index: clang/lib/Headers/limits.h
===================================================================
--- clang/lib/Headers/limits.h
+++ clang/lib/Headers/limits.h
@@ -78,6 +78,8 @@
#define LONG_WIDTH __LONG_WIDTH__
#define ULLONG_WIDTH __LLONG_WIDTH__
#define LLONG_WIDTH __LLONG_WIDTH__
+
+#define BITINT_MAXWIDTH __BITINT_MAXWIDTH__
#endif
#ifdef __CHAR_UNSIGNED__ /* -funsigned-char */
Index: clang/lib/Frontend/InitPreprocessor.cpp
===================================================================
--- clang/lib/Frontend/InitPreprocessor.cpp
+++ clang/lib/Frontend/InitPreprocessor.cpp
@@ -25,6 +25,7 @@
#include "clang/Serialization/ASTReader.h"
#include "llvm/ADT/APFloat.h"
#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
using namespace clang;
static bool MacroBodyEndsInBackslash(StringRef MacroBody) {
@@ -914,6 +915,12 @@
Builder.defineMacro("__LONG_WIDTH__", Twine(TI.getLongWidth()));
Builder.defineMacro("__LLONG_WIDTH__", Twine(TI.getLongLongWidth()));
+ // The max size of a _BitInt is limited in SemaType.cpp to this value. If
+ // someday a target needs to pick a different value for this macro, be sure
+ // to update Sema::BuildBitIntType() as well.
+ Builder.defineMacro("__BITINT_MAXWIDTH__",
+ Twine(llvm::IntegerType::MAX_INT_BITS));
+
DefineTypeSize("__SCHAR_MAX__", TargetInfo::SignedChar, TI, Builder);
DefineTypeSize("__SHRT_MAX__", TargetInfo::SignedShort, TI, Builder);
DefineTypeSize("__INT_MAX__", TargetInfo::SignedInt, TI, Builder);
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