Fix libm build for x86_64.
Change-Id: If89da2d5c3d9a88f78ffd8b260ad0f2fd391c608
diff --git a/libm/amd64/fenv.c b/libm/amd64/fenv.c
index 8b49b35..7ad3be7 100755
--- a/libm/amd64/fenv.c
+++ b/libm/amd64/fenv.c
@@ -1,5 +1,8 @@
+/* $OpenBSD: fenv.c,v 1.3 2012/12/05 23:20:02 deraadt Exp $ */
+/* $NetBSD: fenv.c,v 1.1 2010/07/31 21:47:53 joerg Exp $ */
+
/*-
- * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
+ * Copyright (c) 2004-2005 David Schultz <das (at) FreeBSD.ORG>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -22,143 +25,384 @@
* 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.
- *
- * $FreeBSD$
*/
-#include <sys/cdefs.h>
-#include <sys/types.h>
+#include <fenv.h>
#include <machine/fpu.h>
-#define __fenv_static
-#include "fenv.h"
-
-#ifdef __GNUC_GNU_INLINE__
-#error "This file must be compiled with C99 'inline' semantics"
-#endif
-
-const fenv_t __fe_dfl_env = {
- { 0xffff0000 | __INITIAL_FPUCW__,
- 0xffff0000,
- 0xffffffff,
- { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff }
+/*
+ * The following constant represents the default floating-point environment
+ * (that is, the one installed at program startup) and has type pointer to
+ * const-qualified fenv_t.
+ *
+ * It can be used as an argument to the functions within the <fenv.h> header
+ * that manage the floating-point environment, namely fesetenv() and
+ * feupdateenv().
+ *
+ * x87 fpu registers are 16bit wide. The upper bits, 31-16, are marked as
+ * RESERVED.
+ */
+fenv_t __fe_dfl_env = {
+ {
+ 0xffff0000 | __INITIAL_NPXCW__, /* Control word register */
+ 0xffff0000, /* Status word register */
+ 0xffffffff, /* Tag word register */
+ {
+ 0x00000000,
+ 0x00000000,
+ 0x00000000,
+ 0xffff0000
+ }
},
- __INITIAL_MXCSR__
+ __INITIAL_MXCSR__ /* MXCSR register */
};
-extern inline int feclearexcept(int __excepts);
-extern inline int fegetexceptflag(fexcept_t *__flagp, int __excepts);
+/*
+ * The feclearexcept() function clears the supported floating-point exceptions
+ * represented by `excepts'.
+ */
int
-fesetexceptflag(const fexcept_t *flagp, int excepts)
+feclearexcept(int excepts)
{
- fenv_t env;
+ fenv_t fenv;
+ unsigned int mxcsr;
- __fnstenv(&env.__x87);
- env.__x87.__status &= ~excepts;
- env.__x87.__status |= *flagp & excepts;
- __fldenv(env.__x87);
+ excepts &= FE_ALL_EXCEPT;
- __stmxcsr(&env.__mxcsr);
- env.__mxcsr &= ~excepts;
- env.__mxcsr |= *flagp & excepts;
- __ldmxcsr(env.__mxcsr);
+ /* Store the current x87 floating-point environment */
+ __asm__ __volatile__ ("fnstenv %0" : "=m" (fenv));
+
+ /* Clear the requested floating-point exceptions */
+ fenv.__x87.__status &= ~excepts;
+
+ /* Load the x87 floating-point environent */
+ __asm__ __volatile__ ("fldenv %0" : : "m" (fenv));
+
+ /* Same for SSE environment */
+ __asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+ mxcsr &= ~excepts;
+ __asm__ __volatile__ ("ldmxcsr %0" : : "m" (mxcsr));
return (0);
}
+/*
+ * The fegetexceptflag() function stores 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)
+{
+ unsigned short status;
+ unsigned int mxcsr;
+
+ excepts &= FE_ALL_EXCEPT;
+
+ /* Store the current x87 status register */
+ __asm__ __volatile__ ("fnstsw %0" : "=am" (status));
+
+ /* Store the MXCSR register */
+ __asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+
+ /* Store the results in flagp */
+ *flagp = (status | mxcsr) & excepts;
+
+ return (0);
+}
+
+/*
+ * The feraiseexcept() function raises the supported floating-point exceptions
+ * represented by the argument `excepts'.
+ *
+ * The standard explicitly allows us to execute an instruction that has the
+ * exception as a side effect, but we choose to manipulate the status register
+ * directly.
+ *
+ * The validation of input is being deferred to fesetexceptflag().
+ */
int
feraiseexcept(int excepts)
{
- fexcept_t ex = excepts;
+ excepts &= FE_ALL_EXCEPT;
- fesetexceptflag(&ex, excepts);
- __fwait();
+ fesetexceptflag((fexcept_t *)&excepts, excepts);
+ __asm__ __volatile__ ("fwait");
+
return (0);
}
-extern inline int fetestexcept(int __excepts);
-extern inline int fegetround(void);
-extern inline int fesetround(int __round);
+/*
+ * This function sets the floating-point status flags indicated by the argument
+ * `excepts' to the states stored in the object pointed to by `flagp'. It does
+ * NOT raise any floating-point exceptions, but only sets the state of the flags.
+ */
+int
+fesetexceptflag(const fexcept_t *flagp, int excepts)
+{
+ fenv_t fenv;
+ unsigned int mxcsr;
+ excepts &= FE_ALL_EXCEPT;
+
+ /* Store the current x87 floating-point environment */
+ __asm__ __volatile__ ("fnstenv %0" : "=m" (fenv));
+
+ /* Set the requested status flags */
+ fenv.__x87.__status &= ~excepts;
+ fenv.__x87.__status |= *flagp & excepts;
+
+ /* Load the x87 floating-point environent */
+ __asm__ __volatile__ ("fldenv %0" : : "m" (fenv));
+
+ /* Same for SSE environment */
+ __asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+ mxcsr &= ~excepts;
+ mxcsr |= *flagp & excepts;
+ __asm__ __volatile__ ("ldmxcsr %0" : : "m" (mxcsr));
+
+ return (0);
+}
+
+/*
+ * The fetestexcept() function determines 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)
+{
+ unsigned short status;
+ unsigned int mxcsr;
+
+ excepts &= FE_ALL_EXCEPT;
+
+ /* Store the current x87 status register */
+ __asm__ __volatile__ ("fnstsw %0" : "=am" (status));
+
+ /* Store the MXCSR register state */
+ __asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+
+ return ((status | mxcsr) & excepts);
+}
+
+/*
+ * The fegetround() function gets the current rounding direction.
+ */
+int
+fegetround(void)
+{
+ unsigned short control;
+
+ /*
+ * We assume that the x87 and the SSE unit agree on the
+ * rounding mode. Reading the control word on the x87 turns
+ * out to be about 5 times faster than reading it on the SSE
+ * unit on an Opteron 244.
+ */
+ __asm__ __volatile__ ("fnstcw %0" : "=m" (control));
+
+ return (control & _X87_ROUND_MASK);
+}
+
+/*
+ * The fesetround() function establishes 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)
+{
+ unsigned short control;
+ unsigned int mxcsr;
+
+ /* Check whether requested rounding direction is supported */
+ if (round & ~_X87_ROUND_MASK)
+ return (-1);
+
+ /* Store the current x87 control word register */
+ __asm__ __volatile__ ("fnstcw %0" : "=m" (control));
+
+ /* Set the rounding direction */
+ control &= ~_X87_ROUND_MASK;
+ control |= round;
+
+ /* Load the x87 control word register */
+ __asm__ __volatile__ ("fldcw %0" : : "m" (control));
+
+ /* Same for the SSE environment */
+ __asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+ mxcsr &= ~(_X87_ROUND_MASK << _SSE_ROUND_SHIFT);
+ mxcsr |= round << _SSE_ROUND_SHIFT;
+ __asm__ __volatile__ ("ldmxcsr %0" : : "m" (mxcsr));
+
+ return (0);
+}
+
+/*
+ * The fegetenv() function attempts to store the current floating-point
+ * environment in the object pointed to by envp.
+ */
int
fegetenv(fenv_t *envp)
{
+ /* Store the current x87 floating-point environment */
+ __asm__ __volatile__ ("fnstenv %0" : "=m" (*envp));
- __fnstenv(&envp->__x87);
- __stmxcsr(&envp->__mxcsr);
+ /* Store the MXCSR register state */
+ __asm__ __volatile__ ("stmxcsr %0" : "=m" (envp->__mxcsr));
+
/*
- * fnstenv masks all exceptions, so we need to restore the
- * control word to avoid this side effect.
+ * When an FNSTENV instruction is executed, all pending exceptions are
+ * essentially lost (either the x87 FPU status register is cleared or
+ * all exceptions are masked).
+ *
+ * 8.6 X87 FPU EXCEPTION SYNCHRONIZATION -
+ * Intel(R) 64 and IA-32 Architectures Softare Developer's Manual - Vol1
*/
- __fldcw(envp->__x87.__control);
+ __asm__ __volatile__ ("fldcw %0" : : "m" (envp->__x87.__control));
+
return (0);
}
+/*
+ * The feholdexcept() function saves the current floating-point environment
+ * in the object pointed to by envp, clears the floating-point status flags, and
+ * then installs a non-stop (continue on floating-point exceptions) mode, if
+ * available, for all floating-point exceptions.
+ */
int
feholdexcept(fenv_t *envp)
{
- __uint32_t mxcsr;
+ unsigned int mxcsr;
- __stmxcsr(&mxcsr);
- __fnstenv(&envp->__x87);
- __fnclex();
- envp->__mxcsr = mxcsr;
+ /* Store the current x87 floating-point environment */
+ __asm__ __volatile__ ("fnstenv %0" : "=m" (*envp));
+
+ /* Clear all exception flags in FPU */
+ __asm__ __volatile__ ("fnclex");
+
+ /* Store the MXCSR register state */
+ __asm__ __volatile__ ("stmxcsr %0" : "=m" (envp->__mxcsr));
+
+ /* Clear exception flags in MXCSR */
+ mxcsr = envp->__mxcsr;
mxcsr &= ~FE_ALL_EXCEPT;
- mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT;
- __ldmxcsr(mxcsr);
+
+ /* Mask all exceptions */
+ mxcsr |= FE_ALL_EXCEPT << _SSE_MASK_SHIFT;
+
+ /* Store the MXCSR register */
+ __asm__ __volatile__ ("ldmxcsr %0" : : "m" (mxcsr));
+
return (0);
}
-extern inline int fesetenv(const fenv_t *__envp);
+/*
+ * The fesetenv() function attempts to establish the floating-point environment
+ * represented by the object pointed to by envp. The argument `envp' points
+ * to an object set by a call to fegetenv() or feholdexcept(), or equal a
+ * floating-point environment macro. 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)
+{
+ /* Load the x87 floating-point environent */
+ __asm__ __volatile__ ("fldenv %0" : : "m" (*envp));
+ /* Store the MXCSR register */
+ __asm__ __volatile__ ("ldmxcsr %0" : : "m" (envp->__mxcsr));
+
+ return (0);
+}
+
+/*
+ * The feupdateenv() function saves the currently raised floating-point
+ * exceptions in its automatic storage, installs the floating-point environment
+ * represented by the object pointed to by `envp', and then raises the saved
+ * floating-point exceptions. The argument `envp' shall point to an object set
+ * by a call to feholdexcept() or fegetenv(), or equal a floating-point
+ * environment macro.
+ */
int
feupdateenv(const fenv_t *envp)
{
- __uint32_t mxcsr;
- __uint16_t status;
+ unsigned short status;
+ unsigned int mxcsr;
- __fnstsw(&status);
- __stmxcsr(&mxcsr);
+ /* Store the x87 status register */
+ __asm__ __volatile__ ("fnstsw %0" : "=am" (status));
+
+ /* Store the MXCSR register */
+ __asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+
+ /* Install new floating-point environment */
fesetenv(envp);
- feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT);
+
+ /* Raise any previously accumulated exceptions */
+ feraiseexcept(status | mxcsr);
+
return (0);
}
+/*
+ * The following functions are extentions to the standard
+ */
int
-__feenableexcept(int mask)
+feenableexcept(int mask)
{
- __uint32_t mxcsr, omask;
- __uint16_t control;
+ unsigned int mxcsr, omask;
+ unsigned short control;
mask &= FE_ALL_EXCEPT;
- __fnstcw(&control);
- __stmxcsr(&mxcsr);
- omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
+
+ __asm__ __volatile__ ("fnstcw %0" : "=m" (control));
+ __asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+
+ omask = ~(control | (mxcsr >> _SSE_MASK_SHIFT)) & FE_ALL_EXCEPT;
control &= ~mask;
- __fldcw(control);
- mxcsr &= ~(mask << _SSE_EMASK_SHIFT);
- __ldmxcsr(mxcsr);
+ __asm__ __volatile__ ("fldcw %0" : : "m" (control));
+
+ mxcsr &= ~(mask << _SSE_MASK_SHIFT);
+ __asm__ __volatile__ ("ldmxcsr %0" : : "m" (mxcsr));
+
return (omask);
}
int
-__fedisableexcept(int mask)
+fedisableexcept(int mask)
{
- __uint32_t mxcsr, omask;
- __uint16_t control;
+ unsigned int mxcsr, omask;
+ unsigned short control;
mask &= FE_ALL_EXCEPT;
- __fnstcw(&control);
- __stmxcsr(&mxcsr);
- omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
+
+ __asm__ __volatile__ ("fnstcw %0" : "=m" (control));
+ __asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+
+ omask = ~(control | (mxcsr >> _SSE_MASK_SHIFT)) & FE_ALL_EXCEPT;
control |= mask;
- __fldcw(control);
- mxcsr |= mask << _SSE_EMASK_SHIFT;
- __ldmxcsr(mxcsr);
+ __asm__ __volatile__ ("fldcw %0" : : "m" (control));
+
+ mxcsr |= mask << _SSE_MASK_SHIFT;
+ __asm__ __volatile__ ("ldmxcsr %0" : : "m" (mxcsr));
+
return (omask);
}
-__weak_reference(__feenableexcept, feenableexcept);
-__weak_reference(__fedisableexcept, fedisableexcept);
+int
+fegetexcept(void)
+{
+ unsigned short control;
+
+ /*
+ * We assume that the masks for the x87 and the SSE unit are
+ * the same.
+ */
+ __asm__ __volatile__ ("fnstcw %0" : "=m" (control));
+
+ return (~control & FE_ALL_EXCEPT);
+}