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