Welcome to ftp.nluug.nl Current directory: /pub/os/NetBSD/NetBSD-current/src/external/lgpl3/gmp/dist/mpn/s390_32/

Current bandwidth utilization 1995.31 Mbit/s

All current (2001) S/390 and z/Architecture machines are single-issue,
but some newer machines have a deep pipeline.  Software-pipelining is
therefore beneficial.

* mpn_add_n, mpn_sub_n: Use code along the lines below.  Two-way unrolling
  would be adequate.

  mp_limb_t
  mpn_add_n (mp_ptr rp, mp_srcptr up, mp_srcptr vp, mp_size_t n)
  {
    mp_limb_t a, b, r, cy;
    mp_size_t i;
    mp_limb_t mm = -1;

    cy = 0;
    up += n;
    vp += n;
    rp += n;
    i = -n;
    do
      {
	a = up[i];
	b = vp[i];
	r = a + b + cy;
	rp[i] = r;
	cy = (((a & b) | ((a | b) & (r ^ mm)))) >> 31;
	i++;
      }
    while (i < 0);
    return cy;
  }

* mpn_lshift, mpn_rshift: Use SLDL/SRDL, and two-way unrolling.

* mpn_mul_1, mpn_addmul_1, mpn_submul_1: For machines with just signed
  multiply (MR), use two loops, similar to the corresponding VAX or
  POWER functions.  Handle carry like for mpn_add_n.

 Name                                                           Last modified      Size  
 Parent Directory                                                                    -   
 CVS/                                                           17-Dec-2022 22:27    -   
 esame/                                                         27-Sep-2020 05:01    -   
 README                                                         29-Nov-2013 08:49  899   
 addmul_1.asm                                                   23-Aug-2017 05:01  2.4K  
 copyd.asm                                                      23-Aug-2017 05:01  2.9K  
 copyi.asm                                                      23-Aug-2017 05:01  1.8K  
 gmp-mparam.h                                                   23-Aug-2017 05:01  5.8K  
 logops_n.asm                                                   23-Aug-2017 05:01  5.4K  
 lshift.asm                                                     23-Aug-2017 05:01  2.7K  
 lshiftc.asm                                                    23-Aug-2017 05:01  2.9K  
 mul_1.asm                                                      23-Aug-2017 05:01  2.2K  
 rshift.asm                                                     23-Aug-2017 05:01  2.5K  
 submul_1.asm                                                   23-Aug-2017 05:01  2.5K  

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