sysdeps/ia64/fpu/s_fdim.S

   1 .file "fdim.s"
   2
   3
   4 // Copyright (c) 2001 - 2003, Intel Corporation
   5 // All rights reserved.
   6 //
   7 // Contributed 2001 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 // 06/08/01 Initial version
  43 // 08/23/01 Corrected error tag number
  44 // 05/20/02 Cleaned up namespace and sf0 syntax
  45 // 01/28/03 Improved performance
  46 //
  47 // API
  48 //==============================================================
  49 // double fdim( double x, double y );
  50 // input  floating point f8, f9
  51 // output floating point f8
  52 //
  53 //
  54 // Overview of operation
  55 //==============================================================
  56 // fdim determines the positive difference between the arguments
  57 //   Result = x - y   if x > y
  58 //          = +0      if x <= y
  59 //
  60 // Error support is called if x-y overflows for x > y
  61 //
  62
  63 // Registers used
  64 //==============================================================
  65 // General purpose registers: r14, r32 - r39
  66
  67 rExpBig               = r14
  68
  69 // r36-39 parameters for libm_error_support
  70 GR_SAVE_B0            = r33
  71 GR_SAVE_GP            = r34
  72 GR_SAVE_PFS           = r35
  73
  74 GR_Parameter_X        = r36
  75 GR_Parameter_Y        = r37
  76 GR_Parameter_RESULT   = r38
  77 GR_Parameter_TAG      = r39
  78
  79 // Floating-point registers: f8 - f12
  80
  81 f_tmp_result          = f10
  82 fBig                  = f11
  83 fNormX                = f12
  84
  85 // Predicate registers: p6 - p10
  86
  87
  88 .section .text
  89 GLOBAL_LIBM_ENTRY(fdim)
  90
  91 { .mfi
  92       mov             rExpBig = 0x103ff  // Exponent to indicate overflow
  93       fcmp.le.s1      p6,p7 = f8, f9     // Is x <= y?
  94       nop.i           0
  95 }
  96 { .mfi
  97       nop.m           0
  98       fnorm.s1        fNormX = f8        // Save x
  99       nop.i           0
 100 }
 101 ;;
 102
 103 { .mfi
 104       setf.exp        fBig = rExpBig     // Constant to test for overflow
 105       fcmp.eq.s0      p8,p0 = f8, f9     // Dummy op to set Denormal or Invalid
 106       nop.i           0
 107 }
 108 ;;
 109
 110 { .mfi
 111       nop.m           0
 112       fclass.m        p9,p10 = f8, 0x1e3 // Test for x natval, nan, inf
 113       nop.i           0
 114 }
 115 ;;
 116
 117 { .mfi
 118       nop.m           0
 119 (p6)  fmerge.s        f8 = f0, f0        // Result is +0 if x <= y
 120       nop.i           0
 121 }
 122 { .mfi
 123       nop.m           0
 124 (p7)  fms.d.s0        f8 = f8, f1, f9    // Result is x - y if x > y
 125       nop.i           0
 126 }
 127 ;;
 128
 129 { .mfi
 130       nop.m           0
 131 (p10) fclass.m        p9,p10 = f9, 0x1e3 // Test for y natval, nan, inf
 132       nop.i           0
 133 }
 134 ;;
 135
 136 { .mfi
 137       nop.m           0
 138 (p10) fcmp.ge.s1      p8,p0 = f8, fBig   // Test result for overflow
 139       nop.i           0
 140 }
 141 ;;
 142
 143 { .mbb
 144 (p9)  cmp.ne          p8,p0 = r0,r0      // Clear p8 if x or y natval,nan,inf
 145 (p8)  br.cond.spnt    FDIM_OVERFLOW      // Branch if result overflows
 146       br.ret.sptk     b0                 // Normal return
 147 }
 148 ;;
 149
 150
 151 // Here if result will overflow
 152 FDIM_OVERFLOW:
 153 { .mfi
 154       alloc           r32=ar.pfs,2,2,4,0
 155       fms.d.s0        f_tmp_result = f8,f1,f9 // Normalize result force overflow
 156       nop.i           0
 157 }
 158 { .mfb
 159       mov             GR_Parameter_TAG = 196  // Error code
 160       nop.f           0
 161       br.cond.sptk    __libm_error_region     // Branch to error code
 162 }
 163 ;;
 164
 165 GLOBAL_LIBM_END(fdim)
 166
 167
 168 LOCAL_LIBM_ENTRY(__libm_error_region)
 169 // Call error support to report possible range error
 170 .prologue
 171
 172 { .mfi
 173         add   GR_Parameter_Y=-32,sp            // Parameter 2 value
 174         nop.f 0
 175 .save   ar.pfs,GR_SAVE_PFS
 176         mov  GR_SAVE_PFS=ar.pfs                // Save ar.pfs
 177 }
 178 { .mfi
 179 .fframe 64
 180         add sp=-64,sp                          // Create new stack
 181         nop.f 0
 182         mov GR_SAVE_GP=gp                      // Save gp
 183 };;
 184
 185 { .mmi
 186         stfd [GR_Parameter_Y] = f9,16          // STORE Parameter 2 on stack
 187         add GR_Parameter_X = 16,sp             // Parameter 1 address
 188 .save   b0, GR_SAVE_B0
 189         mov GR_SAVE_B0=b0                      // Save b0
 190 };;
 191
 192 .body
 193 { .mib
 194         stfd [GR_Parameter_X] = fNormX         // STORE Parameter 1 on stack
 195         add   GR_Parameter_RESULT = 0,GR_Parameter_Y // Parameter 3 address
 196         nop.b 0
 197 }
 198 { .mib
 199         stfd [GR_Parameter_Y] = f_tmp_result   // STORE Parameter 3 on stack
 200         add   GR_Parameter_Y = -16,GR_Parameter_Y
 201         br.call.sptk b0=__libm_error_support#  // Call error handling function
 202 };;
 203
 204 { .mmi
 205         add   GR_Parameter_RESULT = 48,sp
 206         nop.m 0
 207         nop.i 0
 208 };;
 209
 210 { .mmi
 211         ldfd  f8 = [GR_Parameter_RESULT]       // Get return result off stack
 212 .restore sp
 213         add   sp = 64,sp                       // Restore stack pointer
 214         mov   b0 = GR_SAVE_B0                  // Restore return address
 215 };;
 216
 217 { .mib
 218         mov   gp = GR_SAVE_GP                  // Restore gp
 219         mov   ar.pfs = GR_SAVE_PFS             // Restore ar.pfs
 220         br.ret.sptk     b0                     // Return
 221 };;
 222
 223 LOCAL_LIBM_END(__libm_error_region)
 224
 225
 226 .type   __libm_error_support#,@function
 227 .global __libm_error_support#
 228