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-rw-r--r--libgcc/config/epiphany/udivsi3-float.c125
1 files changed, 125 insertions, 0 deletions
diff --git a/libgcc/config/epiphany/udivsi3-float.c b/libgcc/config/epiphany/udivsi3-float.c
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+++ b/libgcc/config/epiphany/udivsi3-float.c
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+/* Generic unsigned 32 bit division implementation.
+ Copyright (C) 2009, 2011 Free Software Foundation, Inc.
+ Contributed by Embecosm on behalf of Adapteva, Inc.
+
+This file is part of GCC.
+
+This file 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 3, or (at your option) any
+later version.
+
+This file 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.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+<http://www.gnu.org/licenses/>. */
+
+typedef union { unsigned int i; float f; } fu;
+
+unsigned int __udivsi3 (unsigned int a, unsigned int b);
+
+unsigned int
+__udivsi3 (unsigned int a, unsigned int b)
+{
+ unsigned int d, t, s0, s1, s2, r0, r1;
+ fu u0, u1, u2, u1b, u2b;
+
+ if (b > a)
+ return 0;
+ if ((int) b < 0)
+ return 1;
+
+ /* Assuming B is nonzero, compute S0 such that 0 <= S0,
+ (B << S0+1) does not overflow,
+ A < 4.01 * (B << S0), with S0 choosen as small as possible
+ without taking to much time calculating. */
+#ifdef CONVERT_UNSIGNED
+ u0.f = a;
+ u1.f = b;
+#else /* !CONVERT_UNSIGNED */
+ u0.f = (int) a;
+ u1.f = (int) b;
+#ifdef CONCISE
+ if (a < 0)
+ u0.i = (a >> 8) - 0x00800000 + 0x3f800000 + (31 << 23);
+#else /* To use flag seting / cmove, this can be written as: */
+ {
+ unsigned c = 0xff800000 - 0x4f000000;
+ t = (int)a >> 8;
+ if (t >= c)
+ u0.i = (t - c);
+ }
+#endif
+#endif /* !CONVERT_UNSIGNED */
+ s0 = u0.i + 1 /* Compensate for rounding errors. */
+ - 0x00800000 /* adjust by one */ ;
+ s0 = s0 - u1.i;
+ s0 = (int)s0 >= 0 ? s0 : 0;
+ s0 >>= 23;
+
+ b <<= s0;
+ r1 = 0;
+
+ r0 = 1 << s0;
+ a = ((t=a) - b);
+ if (a <= t)
+ {
+ r1 += r0;
+ a = ((t=a) - b);
+ if (a <= t)
+ do {
+ r1 += r0;
+ a = ((t=a) - b);
+ } while (a <= t);
+ }
+ a += b;
+ d = b - 1;
+
+#define STEP(n) case n: a += a; t = a - d; if (t <= a) a = t;
+ switch (s0)
+ {
+ STEP (31)
+ STEP (30)
+ STEP (29)
+ STEP (28)
+ STEP (27)
+ STEP (26)
+ STEP (25)
+ STEP (24)
+ STEP (23)
+ STEP (22)
+ STEP (21)
+ STEP (20)
+ STEP (19)
+ STEP (18)
+ STEP (17)
+ STEP (16)
+ STEP (15)
+ STEP (14)
+ STEP (13)
+ STEP (12)
+ STEP (11)
+ STEP (10)
+ STEP (9)
+ STEP (8)
+ STEP (7)
+ STEP (6)
+ STEP (5)
+ STEP (4)
+ STEP (3)
+ STEP (2)
+ STEP (1)
+ case 0: ;
+ }
+ r0 = r1 | (r0-1 & a);
+ return r0;
+}