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authorupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
committerupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
commit554fd8c5195424bdbcabf5de30fdc183aba391bd (patch)
tree976dc5ab7fddf506dadce60ae936f43f58787092 /gcc/config/sh/divtab-sh4.c
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Diffstat (limited to 'gcc/config/sh/divtab-sh4.c')
-rw-r--r--gcc/config/sh/divtab-sh4.c85
1 files changed, 85 insertions, 0 deletions
diff --git a/gcc/config/sh/divtab-sh4.c b/gcc/config/sh/divtab-sh4.c
new file mode 100644
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+++ b/gcc/config/sh/divtab-sh4.c
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+/* Copyright (C) 2004, 2009 Free Software Foundation, Inc.
+
+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/>. */
+
+/* Calculate division table for SH2..4 integer division
+ Contributed by Joern Rernnecke
+ joern.rennecke@superh.com */
+
+#include <stdio.h>
+#include <math.h>
+
+int
+main ()
+{
+ int i, j;
+ double q, r, err, max_err = 0, max_s_err = 0;
+
+ puts("/* This table has been generated by divtab-sh4.c. */");
+ puts ("\t.balign 4");
+ puts ("LOCAL(div_table_clz):");
+ /* output some dummy number for 1/0. */
+ printf ("\t.byte\t%d\n", 0);
+ for (i = 1; i <= 128; i++)
+ {
+ int n = 0;
+ if (i == 128)
+ puts ("\
+/* Lookup table translating positive divisor to index into table of\n\
+ normalized inverse. N.B. the '0' entry is also the last entry of the\n\
+ previous table, and causes an unaligned access for division by zero. */\n\
+LOCAL(div_table_ix):");
+ for (j = i; j <= 128; j += j)
+ n++;
+ printf ("\t.byte\t%d\n", n - 7);
+ }
+ for (i = 1; i <= 128; i++)
+ {
+ j = i < 0 ? -i : i;
+ while (j < 128)
+ j += j;
+ printf ("\t.byte\t%d\n", j * 2 - 96*4);
+ }
+ puts("\
+/* 1/64 .. 1/127, normalized. There is an implicit leading 1 in bit 32. */\n\
+ .balign 4\n\
+LOCAL(zero_l):");
+ for (i = 64; i < 128; i++)
+ {
+ if (i == 96)
+ puts ("LOCAL(div_table):");
+ q = 4.*(1<<30)*128/i;
+ r = ceil (q);
+ /* The value for 64 is actually differently scaled that it would
+ appear from this calculation. The implicit part is %01, not 10.
+ Still, since the value in the table is 0 either way, this
+ doesn't matter here. Still, the 1/64 entry is effectively a 1/128
+ entry. */
+ printf ("\t.long\t0x%X\n", (unsigned) r);
+ err = r - q;
+ if (err > max_err)
+ max_err = err;
+ err = err * i / 128;
+ if (err > max_s_err)
+ max_s_err = err;
+ }
+ printf ("\t/* maximum error: %f scaled: %f*/\n", max_err, max_s_err);
+ exit (0);
+}