[src/netbsd-1-5]: src/sys/arch/m68k/fpe Pullup from -current, requested by is...

[is <is%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/d8b48e4dcca0
branches:  netbsd-1-5
changeset: 489535:d8b48e4dcca0
user:      is <is%NetBSD.org@localhost>
date:      Tue Sep 26 09:03:35 2000 +0000

description:
Pullup from -current, requested by is, approved by thorpej:

fpu_emulate.h 1.7, fpu_log.c 1.7: synchronize mantissa length % 32 with fpu_fmovecr.c table
fpu_fmovecr.c 1.8: cheap compile-time consistency check for this
fpu_int.c 1.3: fix bug introduced when reducing mantissa size
This fixes PR 11045.

diffstat:

 sys/arch/m68k/fpe/fpu_emulate.h |  12 ++++++------
 sys/arch/m68k/fpe/fpu_fmovecr.c |   9 +++++++--
 sys/arch/m68k/fpe/fpu_int.c     |   4 ++--
 sys/arch/m68k/fpe/fpu_log.c     |   5 ++---
 4 files changed, 17 insertions(+), 13 deletions(-)

diffs (98 lines):

diff -r eb9030a7459c -r d8b48e4dcca0 sys/arch/m68k/fpe/fpu_emulate.h
--- a/sys/arch/m68k/fpe/fpu_emulate.h   Tue Sep 26 02:07:17 2000 +0000
+++ b/sys/arch/m68k/fpe/fpu_emulate.h   Tue Sep 26 09:03:35 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: fpu_emulate.h,v 1.5.12.1 2000/09/19 03:09:45 minoura Exp $     */
+/*     $NetBSD: fpu_emulate.h,v 1.5.12.2 2000/09/26 09:03:35 is Exp $  */
 
 /*
  * Copyright (c) 1995 Gordon Ross
@@ -44,11 +44,11 @@
  * or `unpacked' form consisting of:
  *     - sign
  *     - unbiased exponent
- *     - mantissa (`1.' + 63-bit fraction + guard + round)
+ *     - mantissa (`1.' + 80-bit fraction + guard + round)
  *     - sticky bit
- * Any implied `1' bit is inserted, giving a 64-bit mantissa that is
+ * Any implied `1' bit is inserted, giving a 81-bit mantissa that is
  * always nonzero.  Additional low-order `guard' and `round' bits are
- * scrunched in, making the entire mantissa 66 bits long.  This is divided
+ * scrunched in, making the entire mantissa 83 bits long.  This is divided
  * into three 32-bit words, with `spare' bits left over in the upper part
  * of the top word (the high bits of fp_mant[0]).  An internal `exploded'
  * number is thus kept within the half-open interval [1.0,2.0) (but see
@@ -76,10 +76,10 @@
        int     fp_sign;                /* 0 => positive, 1 => negative */
        int     fp_exp;                 /* exponent (unbiased) */
        int     fp_sticky;              /* nonzero bits lost at right end */
-       u_int   fp_mant[3];             /* 66-bit mantissa */
+       u_int   fp_mant[3];             /* 83-bit mantissa */
 };
 
-#define        FP_NMANT        67              /* total bits in mantissa (incl g,r) */
+#define        FP_NMANT        83              /* total bits in mantissa (incl g,r) */
 #define        FP_NG           2               /* number of low-order guard bits */
 #define        FP_LG           ((FP_NMANT - 1) & 31)   /* log2(1.0) for fp_mant[0] */
 #define        FP_QUIETBIT     (1 << (FP_LG - 1))      /* Quiet bit in NaNs (0.5) */
diff -r eb9030a7459c -r d8b48e4dcca0 sys/arch/m68k/fpe/fpu_fmovecr.c
--- a/sys/arch/m68k/fpe/fpu_fmovecr.c   Tue Sep 26 02:07:17 2000 +0000
+++ b/sys/arch/m68k/fpe/fpu_fmovecr.c   Tue Sep 26 09:03:35 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: fpu_fmovecr.c,v 1.7 1999/05/30 20:17:48 briggs Exp $   */
+/*     $NetBSD: fpu_fmovecr.c,v 1.7.12.1 2000/09/26 09:03:35 is Exp $  */
 
 /*
  * Copyright (c) 1995  Ken Nakata
@@ -37,8 +37,13 @@
 
 #include "fpu_emulate.h"
 
+/* XXX: quick consistency check */
+#if (FP_1 != 0x40000)
+Error you have to change this table when changing the mantissa size
+#endif
+
 static struct fpn constrom[] = {
-    /* fp_class, fp_sign, fp_exp, fp_sticky, fp_mant[0] ... [3] */
+    /* fp_class, fp_sign, fp_exp, fp_sticky, fp_mant[0] ... [2] */
     { FPC_NUM, 0, 1, 0, { 0x6487e, 0xd5110b46, 0x11a80000 } },
     { FPC_NUM, 0, -2, 0, { 0x4d104, 0xd427de7f, 0xbcc00000 } },
     { FPC_NUM, 0, 1, 0, { 0x56fc2, 0xa2c515da, 0x54d00000 } },
diff -r eb9030a7459c -r d8b48e4dcca0 sys/arch/m68k/fpe/fpu_int.c
--- a/sys/arch/m68k/fpe/fpu_int.c       Tue Sep 26 02:07:17 2000 +0000
+++ b/sys/arch/m68k/fpe/fpu_int.c       Tue Sep 26 09:03:35 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: fpu_int.c,v 1.2 1999/05/30 20:17:48 briggs Exp $       */
+/*     $NetBSD: fpu_int.c,v 1.2.12.1 2000/09/26 09:03:35 is Exp $      */
 
 /*
  * Copyright (c) 1995 Ken Nakata
@@ -60,7 +60,7 @@
     return x;
   }
 
-  clr = 3 - sh / 32;
+  clr = 2 - sh / 32;
   mask = (0xffffffff << (sh % 32));
 
   for (i = 2; i > clr; i--) {
diff -r eb9030a7459c -r d8b48e4dcca0 sys/arch/m68k/fpe/fpu_log.c
--- a/sys/arch/m68k/fpe/fpu_log.c       Tue Sep 26 02:07:17 2000 +0000
+++ b/sys/arch/m68k/fpe/fpu_log.c       Tue Sep 26 09:03:35 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: fpu_log.c,v 1.6 1999/05/30 20:17:48 briggs Exp $       */
+/*     $NetBSD: fpu_log.c,v 1.6.12.1 2000/09/26 09:03:35 is Exp $      */
 
 /*
  * Copyright (c) 1995  Ken Nakata
@@ -314,8 +314,7 @@
 #endif
 
        /* index to the table */
-       i = ((F.fp_mant[0] << (7 - FP_LG)) |
-            (F.fp_mant[1] >> (32 - (7 - FP_LG)))) & 0x7e;
+       i = (F.fp_mant[0] >> (FP_LG - 7)) & 0x7e;
 
 #if FPE_DEBUG
        printf("__fpu_logn: index to logtbl i=%d(%x)\n", i, i);