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-rw-r--r--libm/arm/fesetenv.c62
1 files changed, 62 insertions, 0 deletions
diff --git a/libm/arm/fesetenv.c b/libm/arm/fesetenv.c
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+/* Install given floating-point environment.
+ Copyright (C) 2004-2025 Free Software Foundation, Inc.
+
+ 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/>. */
+
+#include <fenv.h>
+#include <fpu_control.h>
+#include "arm-features.h"
+
+
+int
+fesetenv (const fenv_t *envp)
+{
+ fpu_control_t fpscr, new_fpscr, updated_fpscr;
+
+ /* Fail if a VFP unit isn't present. */
+ if (!ARM_HAVE_VFP)
+ return 1;
+
+ _FPU_GETCW (fpscr);
+
+ if ((envp != FE_DFL_ENV) && (envp != FE_NOMASK_ENV))
+ {
+ /* The new FPSCR is valid, so don't merge the reserved flags. */
+ new_fpscr = envp->__cw;
+
+ /* Write new FPSCR if different (ignoring NZCV flags). */
+ if (((fpscr ^ new_fpscr) & ~_FPU_MASK_NZCV) != 0)
+ _FPU_SETCW (new_fpscr);
+
+ return 0;
+ }
+
+ /* Preserve the reserved FPSCR flags. */
+ new_fpscr = fpscr & _FPU_RESERVED;
+ new_fpscr |= (envp == FE_DFL_ENV) ? _FPU_DEFAULT : _FPU_IEEE;
+
+ if (((new_fpscr ^ fpscr) & ~_FPU_MASK_NZCV) != 0)
+ {
+ _FPU_SETCW (new_fpscr);
+
+ /* Not all VFP architectures support trapping exceptions, so
+ test whether the relevant bits were set and fail if not. */
+ _FPU_GETCW (updated_fpscr);
+
+ return new_fpscr & ~updated_fpscr;
+ }
+
+ return 0;
+}