[glibc/azanella/mips-hw-fp-round] mips: Implement roundevenf with hardware floating-point rounding instruction

[Adhemerval Zanella <azanella@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=b0a9740bac9c0310e287934798eb8d4b34680198

commit b0a9740bac9c0310e287934798eb8d4b34680198
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Wed Dec 27 10:21:24 2023 -0300

    mips: Implement roundevenf with hardware floating-point rounding instruction

Diff:
---
 sysdeps/mips/fpu/roundf_to_integer.h |  3 +++
 sysdeps/mips/fpu/s_roundevenf.c      | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/sysdeps/mips/fpu/roundf_to_integer.h b/sysdeps/mips/fpu/roundf_to_integer.h
index f1a7fefda9..cd30c8de94 100644
--- a/sysdeps/mips/fpu/roundf_to_integer.h
+++ b/sysdeps/mips/fpu/roundf_to_integer.h
@@ -28,6 +28,7 @@ enum round_mode
   CEIL,
   FLOOR,
   TRUNC,
+  ROUNDEVEN,
 };
 
 static inline float
@@ -51,6 +52,8 @@ round_to_integer_float (enum round_mode mode, float x)
   case TRUNC:
     asm ("trunc.l.s %0, %0" : "+f" (r));
     break;
+  case ROUNDEVEN:
+    asm ("round.l.s %0, %0" : "+f" (r));
     break;
   }
   libc_fesetenvf (&fe);
diff --git a/sysdeps/mips/fpu/s_roundevenf.c b/sysdeps/mips/fpu/s_roundevenf.c
new file mode 100644
index 0000000000..605d4f5eea
--- /dev/null
+++ b/sysdeps/mips/fpu/s_roundevenf.c
@@ -0,0 +1,36 @@
+/* Round to integer, toward zero.  MIPS version.
+   Copyright (C) 2023 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/>.  */
+
+#if ((__mips_fpr == 64) \
+      && (__mips_hard_float == 1) \
+      && ((__mips == 32 && __mips_isa_rev > 1) || __mips == 64))
+
+#define NO_MATH_REDIRECT
+#include <math.h>
+#include <roundf_to_integer.h>
+#include <libm-alias-float.h>
+
+float
+__roundevenf (float x)
+{
+  return round_to_integer_float (ROUNDEVEN, x);
+}
+libm_alias_float (__roundeven, roundeven)
+#else
+# include <sysdeps/ieee754/flt-32/s_roundevenf.c>
+#endif