Implement some <fenv.h> functions on systems that don't support them

yet. This includes Cygwin/x86. The code is derived from the GNU C Library.

SheepShaver/src/kpx_cpu/src/mathlib/ieeefp-i386.cpp

@@ -0,0 +1,110 @@
+/*
+ *  ieeefp-i386.cpp - Access to FPU environment, x86 specific code
+ *
+ *  Kheperix (C) 2003-2004 Gwenole Beauchesne
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*
+ *  CPU features
+ */
+
+/* XXX: duplicate from cpu/ppc/ppc-dyngen.cpp! */
+static uint32 cpu_features = 0;
+
+enum {
+	HWCAP_I386_CMOV		= 1 << 15,
+	HWCAP_I386_MMX		= 1 << 23,
+	HWCAP_I386_SSE		= 1 << 25,
+	HWCAP_I386_SSE2		= 1 << 26,
+};
+
+static unsigned int x86_cpuid(void)
+{
+	int fl1, fl2;
+
+	/* See if we can use cpuid. On AMD64 we always can.  */
+	__asm__ ("pushfl; pushfl; popl %0; movl %0,%1; xorl %2,%0;"
+			 "pushl %0; popfl; pushfl; popl %0; popfl"
+			 : "=&r" (fl1), "=&r" (fl2)
+			 : "i" (0x00200000));
+	if (((fl1 ^ fl2) & 0x00200000) == 0)
+		return (0);
+
+	/* Host supports cpuid.  See if cpuid gives capabilities, try
+	   CPUID(0).  Preserve %ebx and %ecx; cpuid insn clobbers these, we
+	   don't need their CPUID values here, and %ebx may be the PIC
+	   register.  */
+	__asm__ ("push %%ecx ; push %%ebx ; cpuid ; pop %%ebx ; pop %%ecx"
+			 : "=a" (fl1) : "0" (0) : "edx", "cc");
+	if (fl1 == 0)
+		return (0);
+
+	/* Invoke CPUID(1), return %edx; caller can examine bits to
+	   determine what's supported.  */
+	__asm__ ("push %%ecx ; push %%ebx ; cpuid ; pop %%ebx ; pop %%ecx" : "=d" (fl2) : "a" (1) : "cc");
+
+	return fl2;
+}
+
+static inline int has_cpu_features(int test_cpu_features)
+{
+	static bool initted = false;
+	if (!initted) {
+		cpu_features = x86_cpuid();
+		initted = true;
+	}
+	return cpu_features & test_cpu_features;
+}
+
+
+/*
+ *  Rounding control
+ */
+
+// Get current rounding direction
+int fegetround(void)
+{
+	unsigned short cw;
+
+	__asm__ __volatile__("fnstcw %0" : "=m" (*&cw));
+
+	return cw & 0xc00;
+}
+
+// Set the rounding direction represented by ROUND
+int fesetround(int round)
+{
+	unsigned short cw;
+
+	if ((round & ~0xc00) != 0)
+		return 1;
+
+	__asm__ __volatile__("fnstcw %0" : "=m" (*&cw));
+	cw &= ~0xc00;
+	cw |= round;
+	__asm__ __volatile__("fldcw %0" : : "m" (*&cw));
+
+	if (has_cpu_features(HWCAP_I386_SSE) != 0) {
+		uint32 xcw;
+		__asm__ __volatile__("stmxcsr %0" : "=m" (*&xcw));
+		xcw &= ~0x6000;
+		xcw |= round << 3;
+		__asm__ __volatile__("ldmxcsr %0" : : "m" (*&xcw));
+	}
+
+	return 0;
+}

SheepShaver/src/kpx_cpu/src/mathlib/ieeefp-i386.hpp

@@ -0,0 +1,52 @@
+/*
+ *  ieeefp-i386.hpp - Access to FPU environment, x86 specific code
+ *
+ *  Kheperix (C) 2003-2004 Gwenole Beauchesne
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef IEEEFP_FENV_I386_H
+#define IEEEFP_FENV_I386_H
+
+// Exceptions
+enum {
+    FE_INVALID = 0x01,
+#define FE_INVALID	FE_INVALID
+    FE_DIVBYZERO = 0x04,
+#define FE_DIVBYZERO	FE_DIVBYZERO
+    FE_OVERFLOW = 0x08,
+#define FE_OVERFLOW	FE_OVERFLOW
+    FE_UNDERFLOW = 0x10,
+#define FE_UNDERFLOW	FE_UNDERFLOW
+    FE_INEXACT = 0x20
+#define FE_INEXACT	FE_INEXACT
+};
+
+#define FE_ALL_EXCEPT	(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW | FE_INEXACT)
+
+// Rounding modes
+enum {
+    FE_TONEAREST = 0,
+#define FE_TONEAREST	FE_TONEAREST
+    FE_DOWNWARD = 0x400,
+#define FE_DOWNWARD	FE_DOWNWARD
+    FE_UPWARD = 0x800,
+#define FE_UPWARD	FE_UPWARD
+    FE_TOWARDZERO = 0xc00
+#define FE_TOWARDZERO	FE_TOWARDZERO
+};
+
+#endif /* IEEEFP_FENV_I386_H */

SheepShaver/src/kpx_cpu/src/mathlib/ieeefp.cpp

@@ -0,0 +1,29 @@
+/*
+ *  ieeefp.cpp - Access to FPU environment
+ *
+ *  Kheperix (C) 2003-2004 Gwenole Beauchesne
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "sysdeps.h"
+
+#ifndef HAVE_FENV_H
+#include "mathlib/ieeefp.hpp"
+#if defined(__i386__)
+#include "mathlib/ieeefp-i386.cpp"
+#endif
+#endif
+

SheepShaver/src/kpx_cpu/src/mathlib/ieeefp.hpp

@@ -0,0 +1,38 @@
+/*
+ *  ieeefp.hpp - Access to FPU environment
+ *
+ *  Kheperix (C) 2003-2004 Gwenole Beauchesne
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef IEEEFP_FENV_H
+#define IEEEFP_FENV_H
+
+#ifdef HAVE_FENV_H
+#include <fenv.h>
+#else
+
+// Arch-dependent definitions
+#if defined(__i386__)
+#include "mathlib/ieeefp-i386.hpp"
+#endif
+
+// Rounding control
+extern "C" int fegetround(void);
+extern "C" int fesetround(int);
+
+#endif /* FENV_H */
+#endif /* IEEEFP_FENV_H */