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+.file "trunc.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
+//==============================================================
+// 07/07/00 Created
+// 05/20/02 Cleaned up namespace and sf0 syntax
+// 01/20/03 Improved performance and reduced code size
+//==============================================================
+
+// API
+//==============================================================
+// double trunc(double x)
+//==============================================================
+
+// general input registers:
+// r14 - r18
+
+rExpBias   = r14
+rSignexp   = r15
+rExp       = r16
+rExpMask   = r17
+rBigexp    = r18
+
+// floating-point registers:
+// f8 - f10
+
+fXtruncInt = f9
+fNormX     = f10
+
+// predicate registers used:
+// p6, p7
+
+// Overview of operation
+//==============================================================
+// double trunc(double x)
+// Return an integer value (represented as a double) less than or
+// equal to x in magnitude.
+// This is x rounded toward zero to an integral value.
+//==============================================================
+
+// 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(trunc)
+
+{ .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              rExpBias    = 0x0FFFF // Form exponent bias
+      fnorm.s1         fNormX  = f8          // Normalize input
+      mov              rExpMask    = 0x1FFFF // Form exponent mask
+}
+;;
+
+{ .mfi
+      nop.m            0
+      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     TRUNC_UNORM           // Branch if x unorm
+}
+;;
+
+TRUNC_COMMON:
+// Return here from TRUNC_UNORM
+{ .mfb
+      and              rExp = rSignexp, rExpMask // Get biased exponent
+(p6)  fma.d.s0         f8 = f8, f1, f0       // Result if x natval, nan, inf
+(p6)  br.ret.spnt      b0                    // Exit if x natval, nan, inf
+}
+;;
+
+{ .mfi
+      cmp.lt           p6,p0 = rExp, rExpBias // Is |x| < 1?
+      fcvt.xf          f8 = fXtruncInt        // Result, assume 1 <= |x| < 2^52
+      cmp.ge           p7,p0 = rExp, rBigexp  // Is |x| >= 2^52?
+}
+;;
+
+// We must correct result if |x| < 1, or |x| >= 2^52
+.pred.rel "mutex",p6,p7
+{ .mfi
+      nop.m            0
+(p6)  fmerge.s         f8 = fNormX, f0        // If |x| < 1, result sgn(x)*0
+      nop.i            0
+}
+{ .mfb
+      nop.m            0
+(p7)  fma.d.s0         f8 = fNormX, f1, f0    // If |x| >= 2^52, result x
+      br.ret.sptk      b0                     // Exit main path
+}
+;;
+
+
+TRUNC_UNORM:
+// Here if x unorm
+{ .mfb
+      getf.exp         rSignexp  = fNormX     // Get signexp, recompute if unorm
+      fcmp.eq.s0       p7,p0 = f8, f0         // Dummy op to set denormal flag
+      br.cond.sptk     TRUNC_COMMON           // Return to main path
+}
+;;
+
+GLOBAL_LIBM_END(trunc)