.file "significandf.s"

// Copyright (c) 2000 - 2003, Intel Corporation

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//

// Contributed 2000 by the Intel Numerics Group, Intel Corporation

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//

// History

//==============================================================

// 02/02/00 Initial version

// 02/03/00 Modified to improve speed

// 05/31/00 Fixed bug when x a double-extended denormal

// 05/20/02 Cleaned up namespace and sf0 syntax

// 02/10/03 Reordered header: .section, .global, .proc, .align

//

// API

//==============================================================

// float significandf(float x)

// Overview of operation

//==============================================================

// If x = sig * 2**n with 1 <= sig < 2

// significandf returns sig

//

// predicate registers used:

// p6, p7

//

// floating-point registers used:

// f8, f9, f10

.section .text

GLOBAL_LIBM_ENTRY(significandf)

// qnan snan inf norm     unorm 0 -+

// 1    1    1   0        0     1 11

// f10 gets f8(sign) with f1(exp,significand)

{ .mfi

      nop.m 999

      fmerge.s       f10 = f8,f1

      nop.i 999

}

{ .mfi

      nop.m 999

      fnorm.s0          f9  = f8

      nop.i 999 ;;

}

// Test for denormal input

{ .mfi

      nop.m 999

      fclass.m.unc   p7,p0 = f8, 0x0b

      nop.i 999 ;;

}

// p6 = TRUE ==> x is not (nan,inf,0)

//               return sign(f8) exp(f1) significand(f8)

// else          x is (nan,inf,0)

//               return sign(f8) exp(f8) significand(f8), normalized.

{ .mfi

      nop.m 999

      fclass.m.unc   p0,p6 = f8, 0xe7

      nop.i 999 ;;

}

{ .mmb

      nop.m 999

      nop.m 999

(p7)  br.cond.spnt SIGNIFICAND_DENORM ;; // Branch if x denormal

}

{ .mfi

      nop.m 999

(p6)  fmerge.se      f8 = f10,f8

      nop.i 999 ;;

}

{ .mfb

      nop.m 999

      fnorm.s.s0        f8 = f8

      br.ret.sptk    b0 ;;

}

SIGNIFICAND_DENORM:

// Here if x denorm

{ .mfi

      nop.m 999

      fmerge.se      f8 = f10,f9

      nop.i 999 ;;

}

// Check if fnorm(x) still denormal, means x double-extended denormal

{ .mfi

      nop.m 999

      fclass.m.unc   p7,p0 = f9, 0x0b

      nop.i 999 ;;

}

// This will be the final result unless x double-extended denormal

{ .mfi

      nop.m 999

      fnorm.s.s0        f8 = f8

      nop.i 999 ;;

}

// If x double-extended denorm, then significand ok, but must merge in

//    correct signexp

{ .mfi

      nop.m 999

(p7)  fmerge.se      f8 = f10,f8

      nop.i 999 ;;

}

// Final normalization if x double-extended denorm

{ .mfb

      nop.m 999

(p7)  fnorm.s.s0        f8 = f8

      br.ret.sptk    b0 ;;

}

GLOBAL_LIBM_END(significandf)