sysdeps/ia64/fpu/s_significandl.S

   1 .file "significandl.s"
   2
   3
   4 // Copyright (c) 2000 - 2003, Intel Corporation
   5 // All rights reserved.
   6 //
   7 // Contributed 2000 by the Intel Numerics Group, Intel Corporation
   8 //
   9 // Redistribution and use in source and binary forms, with or without
  10 // modification, are permitted provided that the following conditions are
  11 // met:
  12 //
  13 // * Redistributions of source code must retain the above copyright
  14 // notice, this list of conditions and the following disclaimer.
  15 //
  16 // * Redistributions in binary form must reproduce the above copyright
  17 // notice, this list of conditions and the following disclaimer in the
  18 // documentation and/or other materials provided with the distribution.
  19 //
  20 // * The name of Intel Corporation may not be used to endorse or promote
  21 // products derived from this software without specific prior written
  22 // permission.
  23
  24 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  25 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  26 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  27 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR ITS
  28 // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  29 // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  30 // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  31 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  32 // OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY OR TORT (INCLUDING
  33 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  34 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35 //
  36 // Intel Corporation is the author of this code, and requests that all
  37 // problem reports or change requests be submitted to it directly at
  38 // http://www.intel.com/software/products/opensource/libraries/num.htm.
  39 //
  40 // History
  41 //==============================================================
  42 // 02/02/00 Initial version
  43 // 02/03/00 Modified to improve speed
  44 // 05/31/00 Fixed bug when x a double-extended denormal
  45 // 05/20/02 Cleaned up namespace and sf0 syntax
  46 // 02/10/03 Reordered header: .section, .global, .proc, .align
  47 //
  48 // API
  49 //==============================================================
  50 // long double significandl(long double x)
  51 //
  52 // Overview of operation
  53 //==============================================================
  54 // If x = sig * 2**n with 1 <= sig < 2
  55 // significandl returns sig
  56 //
  57 // predicate registers used:
  58 // p6, p7
  59 //
  60 // floating-point registers used:
  61 // f8, f9, f10
  62
  63 .section .text
  64 GLOBAL_LIBM_ENTRY(significandl)
  65
  66 // qnan snan inf norm     unorm 0 -+
  67 // 1    1    1   0        0     1 11
  68
  69 // f10 gets f8(sign) with f1(exp,significand)
  70 { .mfi
  71       nop.m 999
  72       fmerge.s       f10 = f8,f1
  73       nop.i 999
  74 }
  75 { .mfi
  76       nop.m 999
  77       fnorm.s0          f9  = f8
  78       nop.i 999 ;;
  79 }
  80
  81 // Test for denormal input
  82 { .mfi
  83       nop.m 999
  84       fclass.m.unc   p7,p0 = f8, 0x0b
  85       nop.i 999 ;;
  86 }
  87
  88 // p6 = TRUE ==> x is not (nan,inf,0)
  89 //               return sign(f8) exp(f1) significand(f8)
  90 // else          x is (nan,inf,0)
  91 //               return sign(f8) exp(f8) significand(f8), normalized.
  92 { .mfi
  93       nop.m 999
  94       fclass.m.unc   p0,p6 = f8, 0xe7
  95       nop.i 999 ;;
  96 }
  97
  98 { .mmb
  99       nop.m 999
 100       nop.m 999
 101 (p7)  br.cond.spnt SIGNIFICAND_DENORM ;; // Branch if x denormal
 102 }
 103
 104 { .mfi
 105       nop.m 999
 106 (p6)  fmerge.se      f8 = f10,f8
 107       nop.i 999 ;;
 108 }
 109
 110 { .mfb
 111       nop.m 999
 112       fnorm.s0          f8 = f8
 113       br.ret.sptk    b0 ;;
 114 }
 115
 116 SIGNIFICAND_DENORM:
 117 // Here if x denorm
 118 { .mfi
 119       nop.m 999
 120       fmerge.se      f8 = f10,f9
 121       nop.i 999 ;;
 122 }
 123
 124 // Check if fnorm(x) still denormal, means x double-extended denormal
 125 { .mfi
 126       nop.m 999
 127       fclass.m.unc   p7,p0 = f9, 0x0b
 128       nop.i 999 ;;
 129 }
 130
 131 // This will be the final result unless x double-extended denormal
 132 { .mfi
 133       nop.m 999
 134       fnorm.s0          f8 = f8
 135       nop.i 999 ;;
 136 }
 137
 138 // If x double-extended denorm, then significand ok, but must merge in
 139 //    correct signexp
 140 { .mfi
 141       nop.m 999
 142 (p7)  fmerge.se      f8 = f10,f8
 143       nop.i 999 ;;
 144 }
 145
 146 // Final normalization if x double-extended denorm
 147 { .mfb
 148       nop.m 999
 149 (p7)  fnorm.s0          f8 = f8
 150       br.ret.sptk    b0 ;;
 151 }
 152
 153 GLOBAL_LIBM_END(significandl)