[src/netbsd-1-4]: src/sys/arch/m68k/fpe pullup 1.1->1.2 (briggs): fix FPE

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

details:   https://anonhg.NetBSD.org/src/rev/1eca4fcd5916
branches:  netbsd-1-4
changeset: 468810:1eca4fcd5916
user:      perry <perry%NetBSD.org@localhost>
date:      Mon Jun 21 15:21:09 1999 +0000

description:
pullup 1.1->1.2 (briggs): fix FPE

diffstat:

 sys/arch/m68k/fpe/fpu_sqrt.c |  51 ++++++-------------------------------------
 1 files changed, 8 insertions(+), 43 deletions(-)

diffs (101 lines):

diff -r 5f40d9d904de -r 1eca4fcd5916 sys/arch/m68k/fpe/fpu_sqrt.c
--- a/sys/arch/m68k/fpe/fpu_sqrt.c      Mon Jun 21 15:20:52 1999 +0000
+++ b/sys/arch/m68k/fpe/fpu_sqrt.c      Mon Jun 21 15:21:09 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: fpu_sqrt.c,v 1.1 1995/11/03 04:47:18 briggs Exp $ */
+/*     $NetBSD: fpu_sqrt.c,v 1.1.24.1 1999/06/21 15:21:09 perry Exp $ */
 
 /*
  * Copyright (c) 1992, 1993
@@ -192,9 +192,9 @@
 {
        register struct fpn *x = &fe->fe_f2;
        register u_int bit, q, tt;
-       register u_int x0, x1, x2, x3;
-       register u_int y0, y1, y2, y3;
-       register u_int d0, d1, d2, d3;
+       register u_int x0, x1, x2;
+       register u_int y0, y1, y2;
+       register u_int d0, d1, d2;
        register int e;
        FPU_DECL_CARRY
 
@@ -224,13 +224,13 @@
         */
 #ifdef FPU_SHL1_BY_ADD
 #define        DOUBLE_X { \
-       FPU_ADDS(x3, x3, x3); FPU_ADDCS(x2, x2, x2); \
+       FPU_ADDS(x2, x2, x2); \
        FPU_ADDCS(x1, x1, x1); FPU_ADDC(x0, x0, x0); \
 }
 #else
 #define        DOUBLE_X { \
        x0 = (x0 << 1) | (x1 >> 31); x1 = (x1 << 1) | (x2 >> 31); \
-       x2 = (x2 << 1) | (x3 >> 31); x3 <<= 1; \
+       x2 <<= 1; \
 }
 #endif
 #if (FP_NMANT & 1) != 0
@@ -243,7 +243,6 @@
        x0 = x->fp_mant[0];
        x1 = x->fp_mant[1];
        x2 = x->fp_mant[2];
-       x3 = x->fp_mant[3];
        e = x->fp_exp;
        if (e & 1)              /* exponent is odd; use sqrt(2mant) */
                DOUBLE_X;
@@ -262,7 +261,7 @@
         * outside of each per-word loop.
         *
         * The calculation `t = y + bit' breaks down into `t0 = y0, ...,
-        * t3 = y3, t? |= bit' for the appropriate word.  Since the bit
+        * t2 = y2, t? |= bit' for the appropriate word.  Since the bit
         * is always a `new' one, this means that three of the `t?'s are
         * just the corresponding `y?'; we use `#define's here for this.
         * The variable `tt' holds the actual `t?' variable.
@@ -355,44 +354,10 @@
        x->fp_mant[2] = q;
 #undef t2
 
-       /* calculate q3.  y0, t0, y1, t1 all fixed; y2, t2, almost done. */
-#define t2 y2
-#define t3 tt
-       q = 0;
-       y3 = 0;
-       bit = 1 << 31;
-       EVEN_DOUBLE;
-       t3 = bit;
-       FPU_SUBS(d3, x3, t3);
-       FPU_SUBCS(d2, x2, t2);
-       FPU_SUBCS(d1, x1, t1);
-       FPU_SUBC(d0, x0, t0);
-       ODD_DOUBLE;
-       if ((int)d0 >= 0) {
-               x0 = d0, x1 = d1, x2 = d2;
-               q |= bit;
-               y2 |= 1;
-       }
-       while ((bit >>= 1) != 0) {
-               EVEN_DOUBLE;
-               t3 = y3 | bit;
-               FPU_SUBS(d3, x3, t3);
-               FPU_SUBCS(d2, x2, t2);
-               FPU_SUBCS(d1, x1, t1);
-               FPU_SUBC(d0, x0, t0);
-               if ((int)d0 >= 0) {
-                       x0 = d0, x1 = d1, x2 = d2;
-                       q |= bit;
-                       y3 |= bit << 1;
-               }
-               ODD_DOUBLE;
-       }
-       x->fp_mant[3] = q;
-
        /*
         * The result, which includes guard and round bits, is exact iff
         * x is now zero; any nonzero bits in x represent sticky bits.
         */
-       x->fp_sticky = x0 | x1 | x2 | x3;
+       x->fp_sticky = x0 | x1 | x2;
        return (x);
 }