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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/mips/math-emu/dp_tlong.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/mips/math-emu/dp_tlong.c')
-rw-r--r--arch/mips/math-emu/dp_tlong.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/arch/mips/math-emu/dp_tlong.c b/arch/mips/math-emu/dp_tlong.c
new file mode 100644
index 00000000000..d71113e0716
--- /dev/null
+++ b/arch/mips/math-emu/dp_tlong.c
@@ -0,0 +1,127 @@
+/* IEEE754 floating point arithmetic
+ * double precision: common utilities
+ */
+/*
+ * MIPS floating point support
+ * Copyright (C) 1994-2000 Algorithmics Ltd.
+ * http://www.algor.co.uk
+ *
+ * ########################################################################
+ *
+ * This program is free software; you can distribute it and/or modify it
+ * under the terms of the GNU General Public License (Version 2) as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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 "ieee754dp.h"
+
+s64 ieee754dp_tlong(ieee754dp x)
+{
+ COMPXDP;
+
+ CLEARCX;
+
+ EXPLODEXDP;
+ FLUSHXDP;
+
+ switch (xc) {
+ case IEEE754_CLASS_SNAN:
+ case IEEE754_CLASS_QNAN:
+ case IEEE754_CLASS_INF:
+ SETCX(IEEE754_INVALID_OPERATION);
+ return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x);
+ case IEEE754_CLASS_ZERO:
+ return 0;
+ case IEEE754_CLASS_DNORM:
+ case IEEE754_CLASS_NORM:
+ break;
+ }
+ if (xe >= 63) {
+ /* look for valid corner case */
+ if (xe == 63 && xs && xm == DP_HIDDEN_BIT)
+ return -0x8000000000000000LL;
+ /* Set invalid. We will only use overflow for floating
+ point overflow */
+ SETCX(IEEE754_INVALID_OPERATION);
+ return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x);
+ }
+ /* oh gawd */
+ if (xe > DP_MBITS) {
+ xm <<= xe - DP_MBITS;
+ } else if (xe < DP_MBITS) {
+ u64 residue;
+ int round;
+ int sticky;
+ int odd;
+
+ if (xe < -1) {
+ residue = xm;
+ round = 0;
+ sticky = residue != 0;
+ xm = 0;
+ }
+ else {
+ /* Shifting a u64 64 times does not work,
+ * so we do it in two steps. Be aware that xe
+ * may be -1 */
+ residue = xm << (xe + 1);
+ residue <<= 63 - DP_MBITS;
+ round = (residue >> 63) != 0;
+ sticky = (residue << 1) != 0;
+ xm >>= DP_MBITS - xe;
+ }
+ odd = (xm & 0x1) != 0x0;
+ switch (ieee754_csr.rm) {
+ case IEEE754_RN:
+ if (round && (sticky || odd))
+ xm++;
+ break;
+ case IEEE754_RZ:
+ break;
+ case IEEE754_RU: /* toward +Infinity */
+ if ((round || sticky) && !xs)
+ xm++;
+ break;
+ case IEEE754_RD: /* toward -Infinity */
+ if ((round || sticky) && xs)
+ xm++;
+ break;
+ }
+ if ((xm >> 63) != 0) {
+ /* This can happen after rounding */
+ SETCX(IEEE754_INVALID_OPERATION);
+ return ieee754di_xcpt(ieee754di_indef(), "dp_tlong", x);
+ }
+ if (round || sticky)
+ SETCX(IEEE754_INEXACT);
+ }
+ if (xs)
+ return -xm;
+ else
+ return xm;
+}
+
+
+u64 ieee754dp_tulong(ieee754dp x)
+{
+ ieee754dp hb = ieee754dp_1e63();
+
+ /* what if x < 0 ?? */
+ if (ieee754dp_lt(x, hb))
+ return (u64) ieee754dp_tlong(x);
+
+ return (u64) ieee754dp_tlong(ieee754dp_sub(x, hb)) |
+ (1ULL << 63);
+}