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+.file "round.s"
+
+
+// Copyright (c) 2000 - 2003, Intel Corporation
+// All rights reserved.
+//
+// Contributed 2000 by the Intel Numerics Group, Intel Corporation
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//
+// * Redistributions in binary form must reproduce the above copyright
+// notice, this list of conditions and the following disclaimer in the
+// documentation and/or other materials provided with the distribution.
+//
+// * The name of Intel Corporation may not be used to endorse or promote
+// products derived from this software without specific prior written
+// permission.
+
+// 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://www.intel.com/software/products/opensource/libraries/num.htm.
+//
+// History
+//==============================================================
+// 10/25/00 Initial version
+// 06/14/01 Changed cmp to an equivalent form
+// 05/20/02 Cleaned up namespace and sf0 syntax
+// 01/20/03 Improved performance and reduced code size
+// 04/18/03 Eliminate possible WAW dependency warning
+// 09/03/03 Improved performance
+//==============================================================
+
+// API
+//==============================================================
+// double round(double x)
+//==============================================================
+
+// general input registers:
+// r14 - r18
+
+rSignexp   = r14
+rExp       = r15
+rExpMask   = r16
+rBigexp    = r17
+rExpHalf   = r18
+
+// floating-point registers:
+// f8 - f13
+
+fXtruncInt = f9
+fNormX     = f10
+fHalf      = f11
+fInc       = f12
+fRem       = f13
+
+// predicate registers used:
+// p6 - p10
+
+// Overview of operation
+//==============================================================
+// double round(double x)
+// Return an integer value (represented as a double) that is x
+// rounded to nearest integer, halfway cases rounded away from
+// zero.
+//  if x>0   result = trunc(x+0.5)
+//  if x<0   result = trunc(x-0.5)
+//
+//==============================================================
+
+// double_extended
+// if the exponent is > 1003e => 3F(true) = 63(decimal)
+// we have a significand of 64 bits 1.63-bits.
+// If we multiply by 2^63, we no longer have a fractional part
+// So input is an integer value already.
+
+// double
+// if the exponent is >= 10033 => 34(true) = 52(decimal)
+// 34 + 3ff = 433
+// we have a significand of 53 bits 1.52-bits. (implicit 1)
+// If we multiply by 2^52, we no longer have a fractional part
+// So input is an integer value already.
+
+// single
+// if the exponent is > 10016 => 17(true) = 23(decimal)
+// we have a significand of 24 bits 1.23-bits. (implicit 1)
+// If we multiply by 2^23, we no longer have a fractional part
+// So input is an integer value already.
+
+
+.section .text
+GLOBAL_LIBM_ENTRY(round)
+
+{ .mfi
+      getf.exp         rSignexp  = f8        // Get signexp, recompute if unorm
+      fcvt.fx.trunc.s1 fXtruncInt  = f8      // Convert to int in significand
+      addl             rBigexp = 0x10033, r0 // Set exponent at which is integer
+}
+{ .mfi
+      mov              rExpHalf    = 0x0FFFE // Form sign and exponent of 0.5
+      fnorm.s1         fNormX  = f8          // Normalize input
+      mov              rExpMask    = 0x1FFFF // Form exponent mask
+}
+;;
+
+{ .mfi
+      setf.exp         fHalf = rExpHalf      // Form 0.5
+      fclass.m         p7,p0 = f8, 0x0b      // Test x unorm
+      nop.i            0
+}
+;;
+
+{ .mfb
+      nop.m            0
+      fclass.m         p6,p0 = f8, 0x1e3     // Test x natval, nan, inf
+(p7)  br.cond.spnt     ROUND_UNORM           // Branch if x unorm
+}
+;;
+
+ROUND_COMMON:
+// Return here from ROUND_UNORM
+{ .mfb
+      nop.m            0
+      fcmp.lt.s1       p8,p9 = f8, f0        // Test if x < 0
+(p6)  br.cond.spnt     ROUND_SPECIAL         // Exit if x natval, nan, inf
+}
+;;
+
+{ .mfi
+      nop.m            0
+      fcvt.xf          f8 = fXtruncInt        // Pre-Result if 0.5 <= |x| < 2^52
+      nop.i            0
+}
+;;
+
+{ .mfi
+      and              rExp = rSignexp, rExpMask // Get biased exponent
+      fmerge.s         fInc = fNormX, f1      // Form increment if |rem| >= 0.5
+      nop.i            0
+}
+;;
+
+{ .mmi
+      cmp.lt           p6,p0 = rExp, rExpHalf // Is |x| < 0.5?
+      cmp.ge           p7,p0 = rExp, rBigexp  // Is |x| >= 2^52?
+      cmp.lt           p10,p0 = rExp, rExpHalf // Is |x| < 0.5?
+}
+;;
+
+// We must correct result if |x| < 0.5, or |x| >= 2^52
+.pred.rel "mutex",p6,p7
+{ .mfi
+      nop.m            0
+(p6)  fmerge.s         f8 = fNormX, f0        // If |x| < 0.5, result sgn(x)*0
+      nop.i            0
+}
+{ .mfb
+(p7)  cmp.eq           p10,p0 = r0, r0        // Also turn on p10 if |x| >= 2^52
+(p7)  fma.d.s0         f8 = fNormX, f1, f0    // If |x| >= 2^52, result x
+(p10) br.ret.spnt      b0                     // Exit |x| < 0.5 or |x| >= 2^52
+}
+;;
+
+// Here if 0.5 <= |x| < 2^52
+{ .mfi
+      nop.m            0
+(p9)  fms.s1           fRem = fNormX, f1, f8  // Get remainder = x - trunc(x)
+      nop.i            0
+}
+{ .mfi
+      nop.m            0
+(p8)  fms.s1           fRem = f8, f1, fNormX  // Get remainder = trunc(x) - x
+      nop.i            0
+}
+;;
+
+{ .mfi
+      nop.m            0
+      fcmp.ge.s1       p9,p0 = fRem, fHalf    // Test |rem| >= 0.5
+      nop.i            0
+}
+;;
+
+// If x < 0 and remainder <= -0.5, then subtract 1 from result
+// If x > 0 and remainder >= +0.5, then add 1 to result
+{ .mfb
+      nop.m            0
+(p9)  fma.d.s0         f8 = f8, f1, fInc
+      br.ret.sptk      b0
+}
+;;
+
+
+ROUND_SPECIAL:
+// Here if x natval, nan, inf
+{ .mfb
+      nop.m            0
+      fma.d.s0         f8 = f8, f1, f0
+      br.ret.sptk      b0
+}
+;;
+
+ROUND_UNORM:
+// Here if x unorm
+{ .mfi
+      getf.exp         rSignexp  = fNormX     // Get signexp, recompute if unorm
+      fcmp.eq.s0       p7,p0 = f8, f0         // Dummy op to set denormal flag
+      nop.i            0
+}
+{ .mfb
+      nop.m            0
+      fcvt.fx.trunc.s1 fXtruncInt  = fNormX   // Convert to int in significand
+      br.cond.sptk     ROUND_COMMON           // Return to main path
+}
+;;
+
+GLOBAL_LIBM_END(round)