reintroduce setfcr-MacOSX-386.c, with 387 instructions

1 files changed, 56 insertions, 0 deletions

diff --git a/lib9/setfcr-MacOSX-386.c b/lib9/setfcr-MacOSX-386.c
new file mode 100644
index 00000000..3589dd80
--- /dev/null
+++ b/lib9/setfcr-MacOSX-386.c
@@ -0,0 +1,56 @@
+/*
+ * Linux 386 fpu support
+ * Mimic Plan9 floating point support
+ */
+
+#include "lib9.h"
+
+void
+setfcr(ulong fcr)
+{
+	__asm__(	"xorb	$0x3f, %%al\n\t"
+			"pushw	%%ax\n\t"
+			"fwait\n\t"
+			"fldcw	(%%esp)\n\t"
+			"popw	%%ax\n\t"
+			: /* no output */
+			: "al" (fcr)
+	);
+}
+
+ulong
+getfcr(void)
+{
+	ulong fcr = 0;
+
+	__asm__(	"pushl	%%eax\n\t"
+			"fwait\n\t"
+			"fstcw	(%%esp)\n\t"
+			"popl	%%eax\n\t"
+			"xorb	$0x3f, %%al\n\t"
+			: "=a"  (fcr)
+			: "eax"	(fcr)
+	);
+	return fcr; 
+}
+
+ulong
+getfsr(void)
+{
+	ulong fsr = -1;
+
+	__asm__(	"fwait\n\t"
+			"fstsw	(%%eax)\n\t"
+			"movl	(%%eax), %%eax\n\t"
+			"andl	$0xffff, %%eax\n\t"
+			: "=a"  (fsr)
+			: "eax" (&fsr)
+	);
+	return fsr;
+}
+
+void
+setfsr(ulong fsr)
+{
+	__asm__("fclex\n\t");
+}