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+.file "modf.s"
+
+// Copyright (c) 2000, 2001, Intel Corporation
+// All rights reserved.
+// 
+// Contributed 2/2/2000 by John Harrison, Ted Kubaska, Bob Norin, Shane Story,
+// and Ping Tak Peter Tang of the Computational Software Lab, Intel Corporation.
+// 
+// WARRANTY DISCLAIMER
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR ITS 
+// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
+// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 
+// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY OR TORT (INCLUDING
+// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
+// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+// 
+// Intel Corporation is the author of this code, and requests that all
+// problem reports or change requests be submitted to it directly at 
+// http://developer.intel.com/opensource.
+//
+// History
+//==============================================================
+// 2/02/00: Initial version
+// 4/04/00: Improved speed, corrected result for NaN input
+// 12/22/00 Fixed so inexact flag is never set, and invalid is not set for 
+//            qnans nor for inputs larger than 2^63.
+//
+// API
+//==============================================================
+// double modf(double x, double *iptr)
+// break a floating point x number into fraction and an exponent
+//
+// input  floating point f8, address in r33
+// output floating point f8 (x fraction), and *iptr (x integral part)
+//
+// OVERVIEW
+//==============================================================
+//
+// NO FRACTIONAL PART: HUGE
+// If
+// for double-extended
+// If the true exponent is greater than or equal 63
+//      1003e ==> 1003e -ffff = 3f = 63(dec)
+// for double
+// If the true exponent is greater than or equal 52
+//                10033 -ffff = 34 = 52(dec)
+// for single
+// If the true exponent is greater than or equal 23
+//                10016 -ffff = 17 = 23(dec)
+// then
+// we are already an integer (p9 true)
+
+// NO INTEGER PART:    SMALL
+//     Is f8 exponent less than register bias (that is, is it
+//     less than 1). If it is, get the right sign of
+//     zero and store this in iptr.
+
+// CALCULATION: NOT HUGE, NOT SMALL
+// To get the integer part
+// Take the floating-point  input and truncate 
+//   then convert  this integer to fp  Call it  MODF_INTEGER_PART
+
+// Subtract  MODF_INTEGER_PART from MODF_NORM_F8 to get fraction part
+// Then put fraction part in f8 
+//      put integer  part MODF_INTEGER_PART into *iptr
+
+// Registers used
+//==============================================================
+
+// predicate registers used: 
+// p6 - p13
+
+//                      0xFFFF           0x10033
+// -----------------------+-----------------+-------------
+//              SMALL     |      NORMAL     | HUGE
+//    p11 --------------->|<----- p12 ----->| <-------------- p9
+//    p10 --------------------------------->|
+//    p13 --------------------------------------------------->|
+//
+
+#include "libm_support.h"
+
+// floating-point registers used: 
+MODF_NORM_F8               = f9
+MODF_FRACTION_PART         = f10
+MODF_INTEGER_PART          = f11
+MODF_INT_INTEGER_PART      = f12
+
+
+// general registers used 
+modf_signexp    = r14
+modf_GR_no_frac = r15
+modf_GR_FFFF    = r16
+modf_17_ones    = r17 
+modf_exp        = r18
+// r33 = iptr
+     
+
+.align 32
+.global modf#
+
+.section .text
+.proc  modf#
+.align 32
+
+
+// Main path is p9, p11, p8 FALSE and p12 TRUE
+
+// Assume input is normalized and get signexp
+// Normalize input just in case
+// Form exponent bias 
+modf: 
+{ .mfi
+      getf.exp  modf_signexp = f8
+      fnorm          MODF_NORM_F8  = f8
+      addl           modf_GR_FFFF  = 0xffff, r0
+}
+// Get integer part of input
+// Form exponent mask
+{ .mfi
+      nop.m 999
+      fcvt.fx.trunc.s1  MODF_INT_INTEGER_PART   = f8
+      mov  modf_17_ones     = 0x1ffff ;;
+}
+
+// Is x nan or inf?
+// qnan snan inf norm     unorm 0 -+
+// 1    1    1   0        0     0 11 = 0xe3 NAN_INF
+// Form biased exponent where input only has an integer part
+{ .mfi
+      nop.m 999
+      fclass.m.unc p6,p13 = f8, 0xe3
+      addl modf_GR_no_frac = 0x10033, r0 ;;
+}
+
+// Mask to get exponent
+// Is x unnorm?
+// qnan snan inf norm     unorm 0 -+
+// 0    0    0   0        1     0 11 = 0x0b UNORM
+// Set p13 to indicate calculation path, else p6 if nan or inf 
+{ .mfi
+      and       modf_exp = modf_17_ones, modf_signexp 
+      fclass.m.unc p8,p0 = f8, 0x0b
+      nop.i 999 ;;
+}
+
+// p11 <== SMALL, no integer part, fraction is everyting
+// p9  <== HUGE,  no fraction part, integer is everything
+// p12 <== NORMAL, fraction part and integer part
+{ .mii
+(p13) cmp.lt.unc p11,p10 = modf_exp, modf_GR_FFFF
+      nop.i 999
+      nop.i 999 ;;
+}
+
+// Is x inf? p6 if inf, p7 if nan
+{ .mfb
+(p10) cmp.ge.unc p9,p12  = modf_exp, modf_GR_no_frac
+(p6)  fclass.m.unc p6,p7 = f8, 0x23
+(p8)  br.cond.spnt L(MODF_DENORM) ;;
+}
+
+L(MODF_COMMON):
+// For HUGE set fraction to signed 0
+{ .mfi
+      nop.m 999
+(p9)  fmerge.s f8 = f8,f0
+      nop.i 999
+}
+// For HUGE set integer part to normalized input
+{ .mfi
+      nop.m 999
+(p9)  fnorm.d MODF_INTEGER_PART = MODF_NORM_F8
+      nop.i 999 ;;
+}
+
+// For SMALL set fraction to normalized input, integer part to signed 0
+{ .mfi
+      nop.m 999
+(p11) fmerge.s MODF_INTEGER_PART = f8,f0
+      nop.i 999
+}
+{ .mfi
+      nop.m 999
+(p11) fnorm.d f8 = MODF_NORM_F8
+      nop.i 999 ;;
+}
+
+// For NORMAL float the integer part
+{ .mfi
+      nop.m 999
+(p12) fcvt.xf    MODF_INTEGER_PART = MODF_INT_INTEGER_PART
+      nop.i 999 ;;
+}
+
+// If x inf set integer part to INF, fraction to signed 0
+{ .mfi
+(p6)  stfd [r33] = MODF_NORM_F8
+(p6)  fmerge.s  f8 = f8,f0
+      nop.i 999 ;;
+}
+
+// If x nan set integer and fraction parts to NaN (quietized)
+{ .mfi
+(p7)  stfd [r33] = MODF_NORM_F8
+(p7)  fmerge.s  f8 = MODF_NORM_F8, MODF_NORM_F8
+      nop.i 999 ;;
+}
+
+{ .mmi
+(p9)  stfd [r33] = MODF_INTEGER_PART
+      nop.m 999
+      nop.i 999 ;;
+}
+
+// For NORMAL compute fraction part
+{ .mfi
+(p11) stfd [r33] = MODF_INTEGER_PART
+(p12) fms.d.s0   f8 = MODF_NORM_F8,f1, MODF_INTEGER_PART
+      nop.i 999 ;;
+}
+
+// For NORMAL test if fraction part is zero; if so append correct sign
+{ .mfi
+      nop.m 999
+(p12) fcmp.eq.unc p7,p0 = MODF_NORM_F8, MODF_INTEGER_PART
+      nop.i 999 ;;
+}
+
+{ .mfi
+(p12) stfd [r33] = MODF_INTEGER_PART
+      nop.f 999
+      nop.i 999 ;;
+}
+
+// For NORMAL if fraction part is zero append sign of input
+{ .mfb
+      nop.m 999
+(p7)  fmerge.s f8 = MODF_NORM_F8, f0
+      br.ret.sptk    b0 ;;
+}
+
+L(MODF_DENORM):
+// If x unorm get signexp from normalized input
+// If x unorm get integer part from normalized input
+{ .mfi
+      getf.exp  modf_signexp = MODF_NORM_F8
+      fcvt.fx.trunc.s1  MODF_INT_INTEGER_PART   = MODF_NORM_F8
+      nop.i 999 ;;
+}
+
+// If x unorm mask to get exponent
+{ .mmi
+      and       modf_exp = modf_17_ones, modf_signexp ;;
+      cmp.lt.unc p11,p10 = modf_exp, modf_GR_FFFF
+      nop.i 999 ;;
+}
+
+{ .mfb
+(p10) cmp.ge.unc p9,p12  = modf_exp, modf_GR_no_frac
+      nop.f 999
+      br.cond.spnt L(MODF_COMMON) ;;
+}
+
+.endp modf
+ASM_SIZE_DIRECTIVE(modf)