Summary:
GCC supports named address spaces macros:
https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html
clang does as well with address spaces:
https://clang.llvm.org/docs/LanguageExtensions.html#memory-references-to-specified-segments
Add the __seg_fs and __seg_gs macros for compatibility with GCC.
<rdar://problem/
52944935>
Subscribers: jkorous, dexonsmith, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D64676
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@366028
91177308-0d34-0410-b5e6-
96231b3b80d8
movl %gs:(%eax), %eax
ret
+You can also use the GCC compatibility macros ``__seg_fs`` and ``__seg_gs`` for
+the same purpose. The preprocessor symbols ``__SEG_FS`` and ``__SEG_GS``
+indicate their support.
+
PowerPC Language Extensions
------------------------------
DefineStd(Builder, "i386", Opts);
}
+ Builder.defineMacro("__SEG_GS");
+ Builder.defineMacro("__SEG_FS");
+ Builder.defineMacro("__seg_gs", "__attribute__((address_space(256)))");
+ Builder.defineMacro("__seg_fs", "__attribute__((address_space(257)))");
+
// Subtarget options.
// FIXME: We are hard-coding the tune parameters based on the CPU, but they
// truly should be based on -mtune options.
--- /dev/null
+// RUN: %clang -target i386-unknown-unknown -x c -E -dM -o - %s | FileCheck -match-full-lines %s
+// RUN: %clang -target x86_64-unknown-unknown -x c -E -dM -o - %s | FileCheck -match-full-lines %s
+
+// CHECK: #define __SEG_FS 1
+// CHECK: #define __SEG_GS 1
+// CHECK: #define __seg_fs __attribute__((address_space(257)))
+// CHECK: #define __seg_gs __attribute__((address_space(256)))