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[PATCH][AArch64] Use builtins for fpcr/fpsr
- From: Wilco Dijkstra <Wilco dot Dijkstra at arm dot com>
- To: "libc-alpha at sourceware dot org" <libc-alpha at sourceware dot org>
- Cc: nd <nd at arm dot com>
- Date: Tue, 9 Jan 2018 11:38:03 +0000
- Subject: [PATCH][AArch64] Use builtins for fpcr/fpsr
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Since GCC 5 has builtin support for accessing FPSR/FPCR, use them when possible
so that the asm instructions can be removed eventually.
GLIBC build and test OK.
ChangeLog:
2018-01-09 Wilco Dijkstra <wdijkstr@arm.com>
* sysdeps/aarch64/fpu/fpu_control.h: Use builtins for accessing FPCR/FPSR.
--
diff --git a/sysdeps/aarch64/fpu/fpu_control.h b/sysdeps/aarch64/fpu/fpu_control.h
index 570e3dca78adbbccdc21ca879c582e1e09196f2d..d7ed28e3c1d7bd4a89087604f80268c36c890c80 100644
--- a/sysdeps/aarch64/fpu/fpu_control.h
+++ b/sysdeps/aarch64/fpu/fpu_control.h
@@ -21,17 +21,24 @@
/* Macros for accessing the FPCR and FPSR. */
-#define _FPU_GETCW(fpcr) \
+#if __GNUC_PREREQ (5,0)
+# define _FPU_GETCW(fpcr) (fpcr = __builtin_aarch64_get_fpcr ())
+# define _FPU_SETCW(fpcr) __builtin_aarch64_set_fpcr (fpcr)
+# define _FPU_GETFPSR(fpsr) (fpsr = __builtin_aarch64_get_fpsr ())
+# define _FPU_SETFPSR(fpsr) __builtin_aarch64_set_fpsr (fpsr)
+#else
+# define _FPU_GETCW(fpcr) \
__asm__ __volatile__ ("mrs %0, fpcr" : "=r" (fpcr))
-#define _FPU_SETCW(fpcr) \
+# define _FPU_SETCW(fpcr) \
__asm__ __volatile__ ("msr fpcr, %0" : : "r" (fpcr))
-#define _FPU_GETFPSR(fpsr) \
+# define _FPU_GETFPSR(fpsr) \
__asm__ __volatile__ ("mrs %0, fpsr" : "=r" (fpsr))
-#define _FPU_SETFPSR(fpsr) \
+# define _FPU_SETFPSR(fpsr) \
__asm__ __volatile__ ("msr fpsr, %0" : : "r" (fpsr))
+#endif
/* Reserved bits should be preserved when modifying register
contents. These two masks indicate which bits in each of FPCR and