[PATCH 5/5] riscv: Enable TOINT_INTRINSICS with Zfa

Julian Zhu <[email protected]> Thu, 6 Aug 2026 18:25:31 +0800
Newsgroups gmane.comp.lib.glibc.alpha
Message-ID <[email protected]>
Provide Zfa-gated roundtoint and converttoint helpers for the common libm argument-reduction code.  Zfa turns roundtoint into one fround.d instruction while non-Zfa builds continue using the generic reduction path.

Signed-off-by: Julian Zhu <[email protected]>
---
 sysdeps/riscv/rvd/math_private.h | 44 ++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 sysdeps/riscv/rvd/math_private.h

diff --git a/sysdeps/riscv/rvd/math_private.h b/sysdeps/riscv/rvd/math_private.h
new file mode 100644
index 0000000000..9760702560
--- /dev/null
+++ b/sysdeps/riscv/rvd/math_private.h
@@ -0,0 +1,44 @@
+/* Configure optimized libm functions.  RISC-V version.
+   Copyright (C) 2026 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 RISCV_MATH_PRIVATE_H
+#define RISCV_MATH_PRIVATE_H 1
+
+#include <stdint.h>
+
+#ifdef __riscv_zfa
+# define TOINT_INTRINSICS 1
+
+static inline double
+roundtoint (double x)
+{
+  return __builtin_round (x);		/* Zfa: single fround.d.  */
+}
+
+static inline int32_t
+converttoint (double x)
+{
+  int32_t r;
+  asm ("fcvt.w.d %0, %1, rmm" : "=r" (r) : "f" (x));
+  return r;
+}
+#endif /* __riscv_zfa */
+
+#include_next <math_private.h>
+
+#endif /* RISCV_MATH_PRIVATE_H  */
-- 
2.53.0