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[PATCH 15/17] S390: Implement math-barriers math_opt_barrier and math_force_eval.
- From: Stefan Liebler <stli at linux dot ibm dot com>
- To: libc-alpha at sourceware dot org
- Cc: Stefan Liebler <stli at linux dot ibm dot com>
- Date: Mon, 4 Nov 2019 16:27:22 +0100
- Subject: [PATCH 15/17] S390: Implement math-barriers math_opt_barrier and math_force_eval.
- References: <1572881244-6781-1-git-send-email-stli@linux.ibm.com>
This patch implements the s390 specific math barriers in order
to omit the store and load from stack if possible.
---
sysdeps/s390/fpu/math-barriers.h | 46 ++++++++++++++++++++++++++++++++
1 file changed, 46 insertions(+)
create mode 100644 sysdeps/s390/fpu/math-barriers.h
diff --git a/sysdeps/s390/fpu/math-barriers.h b/sysdeps/s390/fpu/math-barriers.h
new file mode 100644
index 0000000000..7c3e6b15e0
--- /dev/null
+++ b/sysdeps/s390/fpu/math-barriers.h
@@ -0,0 +1,46 @@
+/* Control when floating-point expressions are evaluated. s390 version.
+ Copyright (C) 2019 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#ifndef S390_MATH_BARRIERS_H
+#define S390_MATH_BARRIERS_H 1
+
+#ifdef HAVE_S390_VX_GCC_SUPPORT
+# define ASM_CONSTRAINT_VR "v"
+#else
+# define ASM_CONSTRAINT_VR
+#endif
+
+#define math_opt_barrier(x) \
+ ({ __typeof (x) __x = (x); \
+ if (__builtin_types_compatible_p (__typeof (x), _Float128)) \
+ __asm__ ("# math_opt_barrier_f128 %0" : "+fm" (__x)); \
+ else \
+ __asm__ ("# math_opt_barrier %0" \
+ : "+f" ASM_CONSTRAINT_VR "m" (__x)); \
+ __x; })
+#define math_force_eval(x) \
+ ({ __typeof (x) __x = (x); \
+ if (__builtin_types_compatible_p (__typeof (x), _Float128)) \
+ __asm__ __volatile__ ("# math_force_eval_f128 %0" \
+ : : "fm" (__x)); \
+ else \
+ __asm__ __volatile__ ("# math_force_eval %0" \
+ : : "f" ASM_CONSTRAINT_VR "m" (__x)); \
+ })
+
+#endif
--
2.19.1