diff --git a/src/libmach/fpformat.c b/src/libmach/fpformat.c
new file mode 100644
index 0000000..a94a096
--- /dev/null
+++ b/src/libmach/fpformat.c
@@ -0,0 +1,65 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <mach.h>
+
+/*
+ *	Format floating point registers
+ *
+ *	Register codes in format field:
+ *	'X' - print as 32-bit hexadecimal value
+ *	'F' - 64-bit double register when modif == 'F'; else 32-bit single reg
+ *	'f' - 32-bit ieee float
+ *	'8' - big endian 80-bit ieee extended float
+ *	'3' - little endian 80-bit ieee extended float with hole in bytes 8&9
+ */
+int
+fpformat(Map *map, Regdesc *rp, char *buf, uint n, uint modif)
+{
+	char reg[12];
+	u32int r;
+
+	switch(rp->format)
+	{
+	case 'X':
+		if (get4(map, rp->offset, &r) < 0)
+			return -1;
+		snprint(buf, n, "%lux", r);
+		break;
+	case 'F':	/* first reg of double reg pair */
+		if (modif == 'F')
+		if ((rp->format=='F') || (((rp+1)->flags&RFLT) && (rp+1)->format == 'f')) {
+			if (get1(map, rp->offset, (uchar *)reg, 8) < 0)
+				return -1;
+			mach->ftoa64(buf, n, reg);
+			if (rp->format == 'F')
+				return 1;
+			return 2;
+		}	
+			/* treat it like 'f' */
+		if (get1(map, rp->offset, (uchar *)reg, 4) < 0)
+			return -1;
+		mach->ftoa32(buf, n, reg);
+		break;
+	case 'f':	/* 32 bit float */
+		if (get1(map, rp->offset, (uchar *)reg, 4) < 0)
+			return -1;
+		mach->ftoa32(buf, n, reg);
+		break;
+	case '3':	/* little endian ieee 80 with hole in bytes 8&9 */
+		if (get1(map, rp->offset, (uchar *)reg, 10) < 0)
+			return -1;
+		memmove(reg+10, reg+8, 2);	/* open hole */
+		memset(reg+8, 0, 2);		/* fill it */
+		leieeeftoa80(buf, n, reg);
+		break;
+	case '8':	/* big-endian ieee 80 */
+		if (get1(map, rp->offset, (uchar *)reg, 10) < 0)
+			return -1;
+		beieeeftoa80(buf, n, reg);
+		break;
+	default:	/* unknown */
+		break;
+	}
+	return 1;
+}