|
@@ -0,0 +1,94 @@
|
|
|
+/*
|
|
|
+ * linux/arch/arm/vfp/vfpdouble.c
|
|
|
+ *
|
|
|
+ * This code is derived in part from John R. Housers softfloat library, which
|
|
|
+ * carries the following notice:
|
|
|
+ *
|
|
|
+ * ===========================================================================
|
|
|
+ * This C source file is part of the SoftFloat IEC/IEEE Floating-point
|
|
|
+ * Arithmetic Package, Release 2.
|
|
|
+ *
|
|
|
+ * Written by John R. Hauser. This work was made possible in part by the
|
|
|
+ * International Computer Science Institute, located at Suite 600, 1947 Center
|
|
|
+ * Street, Berkeley, California 94704. Funding was partially provided by the
|
|
|
+ * National Science Foundation under grant MIP-9311980. The original version
|
|
|
+ * of this code was written as part of a project to build a fixed-point vector
|
|
|
+ * processor in collaboration with the University of California at Berkeley,
|
|
|
+ * overseen by Profs. Nelson Morgan and John Wawrzynek. More information
|
|
|
+ * is available through the web page `http://HTTP.CS.Berkeley.EDU/~jhauser/
|
|
|
+ * arithmetic/softfloat.html'.
|
|
|
+ *
|
|
|
+ * THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort
|
|
|
+ * has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT
|
|
|
+ * TIMES RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO
|
|
|
+ * PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY
|
|
|
+ * AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.
|
|
|
+ *
|
|
|
+ * Derivative works are acceptable, even for commercial purposes, so long as
|
|
|
+ * (1) they include prominent notice that the work is derivative, and (2) they
|
|
|
+ * include prominent notice akin to these three paragraphs for those parts of
|
|
|
+ * this code that are retained.
|
|
|
+ * ===========================================================================
|
|
|
+ */
|
|
|
+#include <linux/kernel.h>
|
|
|
+#include <linux/bitops.h>
|
|
|
+
|
|
|
+#include <asm/div64.h>
|
|
|
+#include <asm/vfp.h>
|
|
|
+
|
|
|
+#include "vfpinstr.h"
|
|
|
+#include "vfp.h"
|
|
|
+
|
|
|
+static struct vfp_double vfp_double_default_qnan = {
|
|
|
+ .exponent = 2047,
|
|
|
+ .sign = 0,
|
|
|
+ .significand = VFP_DOUBLE_SIGNIFICAND_QNAN,
|
|
|
+};
|
|
|
+
|
|
|
+static void vfp_double_dump(const char *str, struct vfp_double *d)
|
|
|
+{
|
|
|
+ pr_debug("VFP: %s: sign=%d exponent=%d significand=%016llx\n",
|
|
|
+ str, d->sign != 0, d->exponent, d->significand);
|
|
|
+}
|
|
|
+
|
|
|
+static void vfp_double_normalise_denormal(struct vfp_double *vd)
|
|
|
+{
|
|
|
+ int bits = 31 - fls(vd->significand >> 32);
|
|
|
+ if (bits == 31)
|
|
|
+ bits = 63 - fls(vd->significand);
|
|
|
+
|
|
|
+ vfp_double_dump("normalise_denormal: in", vd);
|
|
|
+
|
|
|
+ if (bits) {
|
|
|
+ vd->exponent -= bits - 1;
|
|
|
+ vd->significand <<= bits;
|
|
|
+ }
|
|
|
+
|
|
|
+ vfp_double_dump("normalise_denormal: out", vd);
|
|
|
+}
|
|
|
+
|
|
|
+u32 vfp_double_normaliseround(int dd, struct vfp_double *vd, u32 fpscr, u32 exceptions, const char *func)
|
|
|
+{
|
|
|
+ u64 significand, incr;
|
|
|
+ int exponent, shift, underflow;
|
|
|
+ u32 rmode;
|
|
|
+
|
|
|
+ vfp_double_dump("pack: in", vd);
|
|
|
+
|
|
|
+ /*
|
|
|
+ * Infinities and NaNs are a special case.
|
|
|
+ */
|
|
|
+ if (vd->exponent == 2047 && (vd->significand == 0 || exceptions))
|
|
|
+ goto pack;
|
|
|
+
|
|
|
+ /*
|
|
|
+ * Special-case zero.
|
|
|
+ */
|
|
|
+ if (vd->significand == 0) {
|
|
|
+ vd->exponent = 0;
|
|
|
+ goto pack;
|
|
|
+ }
|
|
|
+
|
|
|
+ exponent = vd->exponent;
|
|
|
+ significand = vd->significand;
|
|
|
+
|