[src/trunk]: src/lib/libm/arch/arm Add a C99 <fenv.h> implementation for arm.

[matt <matt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ad6bfdf9bd92
branches:  trunk
changeset: 786454:ad6bfdf9bd92
user:      matt <matt%NetBSD.org@localhost>
date:      Sun Apr 28 21:06:34 2013 +0000

description:
Add a C99 <fenv.h> implementation for arm.

diffstat:

 lib/libm/arch/arm/fenv.c |  279 +++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 279 insertions(+), 0 deletions(-)

diffs (283 lines):

diff -r 89004ccfc0b1 -r ad6bfdf9bd92 lib/libm/arch/arm/fenv.c
--- /dev/null   Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/libm/arch/arm/fenv.c  Sun Apr 28 21:06:34 2013 +0000
@@ -0,0 +1,279 @@
+/*-
+ * Copyright (c) 2013 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Matt Thomas of 3am Software Foundry.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__RCSID("$NetBSD: fenv.c,v 1.1 2013/04/28 21:06:34 matt Exp $");
+
+#include <sys/types.h>
+#include <assert.h>
+#include <fenv.h>
+#include <string.h>
+#include <unistd.h>
+
+#ifdef __SOFTFP__
+#include <ieeefp.h>
+#include <sys/signal.h>
+#include <sys/siginfo.h>
+#else
+#include <inttypes.h>
+#include <arm/armreg.h>
+#endif
+
+#include <arm/vfpreg.h>
+
+const fenv_t __fe_dfl_env = VFP_FPSCR_FZ|VFP_FPSCR_DN|VFP_FPSCR_RN;
+
+/*
+ * The feclearexcept() function shall attempt to clear the supported
+ * floating-point exceptions represented by excepts.
+ */
+int
+feclearexcept(int excepts)
+{
+       _DIAGASSERT((except & ~FE_EXCEPT_ALL) == 0);
+#ifdef __SOFTFP__
+       int old = fpresetsticky(excepts);
+       return old & ~excepts;
+#else
+       int tmp = armreg_fpscr_read() & ~__SHIFTIN(excepts, VFP_FPSCR_CSUM);
+       armreg_fpscr_write(tmp);
+       return __SHIFTOUT(tmp, VFP_FPSCR_CSUM);
+#endif
+}
+
+/*
+ * The fegetexceptflag() function shall attempt to store an
+ * implementation-defined representation of the states of the floating-point
+ * status flags indicated by the argument excepts in the object pointed to by
+ * the argument flagp.
+ */
+int
+fegetexceptflag(fexcept_t *flagp, int excepts)
+{
+       _DIAGASSERT((except & ~FE_EXCEPT_ALL) == 0);
+#ifdef __SOFTFP__
+       *flagp = fpgetsticky() & excepts;
+#else
+       *flagp = __SHIFTOUT(armreg_fpscr_read(), VFP_FPSCR_CSUM) & excepts;
+#endif
+       return 0;
+}
+
+/*
+ * The feraiseexcept() function shall attempt to raise the supported
+ * floating-point exceptions represented by the argument excepts. The order
+ * in which these floating-point exceptions are raised is unspecified. 
+ */
+int
+feraiseexcept(int excepts)
+{
+       _DIAGASSERT((except & ~FE_EXCEPT_ALL) == 0);
+#ifdef __SOFTFP__
+       excepts &= fpgetsticky();
+
+       if (excepts) {
+               siginfo_t info;
+               memset(&info, 0, sizeof info);
+               info.si_signo = SIGFPE;
+               info.si_pid = getpid();
+               info.si_uid = geteuid();
+               if (excepts & FE_UNDERFLOW)
+                       info.si_code = FPE_FLTUND;
+               else if (excepts & FE_OVERFLOW)
+                       info.si_code = FPE_FLTOVF;
+               else if (excepts & FE_DIVBYZERO)
+                       info.si_code = FPE_FLTDIV;
+               else if (excepts & FE_INVALID)
+                       info.si_code = FPE_FLTINV;
+               else if (excepts & FE_INEXACT)
+                       info.si_code = FPE_FLTRES;
+               sigqueueinfo(getpid(), &info);
+       }
+#else
+       uint32_t fpscr = armreg_fpscr_read();
+       fpscr = (fpscr & ~VFP_FPSCR_ESUM) | __SHIFTIN(excepts, VFP_FPSCR_ESUM);
+       armreg_fpscr_write(fpscr);
+#endif
+       return 0;
+}
+
+/*
+ * The fesetexceptflag() function shall attempt to set the floating-point
+ * status flags indicated by the argument excepts to the states stored in the
+ * object pointed to by flagp. The value pointed to by flagp shall have been
+ * set by a previous call to fegetexceptflag() whose second argument
+ * represented at least those floating-point exceptions represented by the
+ * argument excepts. This function does not raise floating-point exceptions,
+ * but only sets the state of the flags.
+ */
+int
+fesetexceptflag(const fexcept_t *flagp, int excepts)
+{
+       _DIAGASSERT((except & ~FE_EXCEPT_ALL) == 0);
+#ifdef __SOFTFP__
+       fpsetsticky((fpgetsticky() & ~excepts) | (excepts & *flagp));
+#else
+       int fpscr = armreg_fpscr_read();
+       fpscr &= ~__SHIFTIN(excepts, VFP_FPSCR_CSUM);
+       fpscr |= __SHIFTIN((*flagp & excepts), VFP_FPSCR_CSUM);
+       armreg_fpscr_write(fpscr);
+#endif
+       return 0;
+}
+
+/*
+ * The fetestexcept() function shall determine which of a specified subset of
+ * the floating-point exception flags are currently set. The excepts argument
+ * specifies the floating-point status flags to be queried.
+ */
+int
+fetestexcept(int excepts)
+{
+       _DIAGASSERT((except & ~FE_EXCEPT_ALL) == 0);
+#ifdef __SOFTFP__
+       return fpgetsticky() & excepts;
+#else
+       return __SHIFTOUT(armreg_fpscr_read(), VFP_FPSCR_CSUM) & excepts;
+#endif
+}
+
+/*
+ * The fegetround() function shall get the current rounding direction.
+ */
+int
+fegetround(void)
+{
+#ifdef __SOFTFP__
+       return fpgetround();
+#else
+       return __SHIFTOUT(armreg_fpscr_read(), VFP_FPSCR_RMODE);
+#endif
+}
+
+/*
+ * The fesetround() function shall establish the rounding direction represented
+ * by its argument round. If the argument is not equal to the value of a
+ * rounding direction macro, the rounding direction is not changed.
+ */
+int
+fesetround(int round)
+{
+       _DIAGASSERT(!(round & ~__SHIFTOUT(VFP_FPSCR_RMODE, VFP_FPSCR_RMODE)));
+#ifdef __SOFTFP__
+       (void)fpsetround(round);
+#else
+       int fpscr = armreg_fpscr_read() & ~VFP_FPSCR_RMODE;
+       fpscr |= __SHIFTIN(round, VFP_FPSCR_RMODE);
+       armreg_fpscr_write(fpscr);
+#endif
+       return 0;
+}
+
+/*
+ * The fegetenv() function shall attempt to store the current floating-point
+ * environment in the object pointed to by envp.
+ */
+int
+fegetenv(fenv_t *envp)
+{
+#ifdef __SOFTFP__
+       *envp = __SHIFTIN(fpgetround(), VFP_FPSCR_RMODE)
+           | __SHIFTIN(fpgetmask(), VFP_FPSCR_ESUM)
+           | __SHIFTIN(fpgetsticky(), VFP_FPSCR_CSUM);
+#else
+       *envp = armreg_fpscr_read();
+#endif
+       return 0;
+}
+
+/*
+ * The feholdexcept() function shall save the current floating-point
+ * environment in the object pointed to by envp, clear the floating-point
+ * status flags, and then install a non-stop (continue on floating-point
+ * exceptions) mode, if available, for all floating-point exceptions.
+ */
+int
+feholdexcept(fenv_t *envp)
+{
+#ifdef __SOFTFP__
+       *envp = __SHIFTIN(fpgetround(), VFP_FPSCR_RMODE)
+           | __SHIFTIN(fpgetmask(), VFP_FPSCR_ESUM)
+           | __SHIFTIN(fpgetsticky(), VFP_FPSCR_CSUM);
+       fpsetmask(0);
+       fpsetsticky(0);
+#else
+       *envp = armreg_fpscr_read();
+       armreg_fpscr_write((*envp) & ~(VFP_FPSCR_ESUM|VFP_FPSCR_CSUM));
+#endif
+       return 0;
+}
+
+/*
+ * The fesetenv() function shall attempt to establish the floating-point
+ * environment represented by the object pointed to by envp. The fesetenv()
+ * function does not raise floating-point exceptions, but only installs the
+ * state of the floating-point status flags represented through its argument.
+ */
+int
+fesetenv(const fenv_t *envp)
+{
+#ifdef __SOFTFP__
+       (void)fpsetround(__SHIFTIN(*envp, VFP_FPSCR_RMODE));
+       (void)fpsetmask(__SHIFTOUT(*envp, VFP_FPSCR_ESUM));
+       (void)fpsetsticky(__SHIFTOUT(*envp, VFP_FPSCR_CSUM));
+#else
+       armreg_fpscr_write(*envp);
+#endif
+       return 0;
+}
+
+/*
+ * The feupdateenv() function shall attempt to save the currently raised
+ * floating-point exceptions in its automatic storage, attempt to install the
+ * floating-point environment represented by the object pointed to by envp,
+ * and then attempt to raise the saved floating-point exceptions. 
+ */
+int
+feupdateenv(const fenv_t *envp)
+{
+       _DIAGASSERT(envp != NULL);
+
+#ifdef __SOFTFP__
+       (void)fpsetround(__SHIFTIN(*envp, VFP_FPSCR_RMODE));
+       (void)fpsetmask(fpgetmask() | __SHIFTOUT(*envp, VFP_FPSCR_ESUM));
+       (void)fpsetsticky(fpgetsticky() | __SHIFTOUT(*envp, VFP_FPSCR_CSUM));
+#else
+       int fpscr = armreg_fpscr_read() & ~(VFP_FPSCR_ESUM|VFP_FPSCR_CSUM);
+       fpscr |= *envp;
+       armreg_fpscr_write(fpscr);
+#endif
+
+       /* Success */
+       return 0;
+}