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+.file "trunc.s"
+
+// Copyright (c) 2000, 2001, Intel Corporation
+// All rights reserved.
+// 
+// Contributed 7/7/2000 by John Harrison, Cristina Iordache, 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.
+//
+.align 32
+.global trunc#
+
+.section .text
+.proc  trunc#
+.align 32
+
+// History
+//==============================================================
+// 7/7/00: Created 
+//==============================================================
+
+// API
+//==============================================================
+// double trunc(double x)
+//==============================================================
+
+#include "libm_support.h"
+
+// general input registers:  
+TRUNC_GR_FFFF      = r14
+TRUNC_GR_signexp   = r15
+TRUNC_GR_exponent  = r16
+TRUNC_GR_expmask   = r17
+TRUNC_GR_bigexp    = r18
+
+// floating-point registers:
+// f8, f9, f11, f12
+
+// predicate registers used: 
+// p6, p7, p8, p9, p10, p11
+
+// 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.
+
+trunc:
+
+{ .mfi
+      getf.exp         TRUNC_GR_signexp  = f8
+      fcvt.fx.trunc.s1 f9  = f8
+      addl             TRUNC_GR_bigexp = 0x10033, r0
+}
+{ .mfi
+      mov              TRUNC_GR_FFFF    = 0x0FFFF
+      fnorm.d          f11  = f8
+      mov              TRUNC_GR_expmask    = 0x1FFFF 
+};;
+//    get the exponent of x
+//    convert x to integer in signficand of f9 
+//    Normalize x - this will raise invalid on SNaNs, the
+//    denormal operand flag - and possibly a spurious U flag
+//    get exponent only mask (will exclude sign bit)
+
+{ .mfi
+      nop.m            0
+      fclass.m         p7,p8 = f8, 0x0b  
+      nop.i            0
+}
+{ .mfi
+      nop.m            0
+      fcmp.eq.unc.s1   p9,p0 = f8,f0
+      nop.i      0       
+};;
+//    fclass to set p7 if unnorm 
+{ .mmi
+      and              TRUNC_GR_exponent = TRUNC_GR_signexp, TRUNC_GR_expmask ;;
+(p8)  cmp.ge.unc       p10,p11 = TRUNC_GR_exponent, TRUNC_GR_bigexp
+(p8)  cmp.ne.unc       p6,p0 = TRUNC_GR_exponent, TRUNC_GR_signexp
+};;
+//    Get the exponent of x
+//    Test if exponent such that result already an integer
+//    Test if x < 0
+{ .mmi
+(p9)  cmp.eq.andcm     p10,p11 = r0, r0 
+(p6)  cmp.lt.unc       p6,p0 = TRUNC_GR_exponent, TRUNC_GR_FFFF
+      nop.i 0 
+};;
+//    If -1 < x < 0, set p6, turn off p10 and p11, and set result to -0.0
+{ .mfb
+(p6)  cmp.eq.andcm     p10,p11 = r0, r0 
+(p6)  fmerge.s         f8 = f8, f0
+      nop.b 0
+};;
+//    If not a unnorm, set p10 if x already is a big int, nan, or inf?
+//    If not a unnorm, set p10 if x already is a big int, nan, or inf?
+.pred.rel "mutex",p10,p11    
+{ .mfb
+      nop.m            0
+(p11) fcvt.xf          f8   = f9 
+      nop.b            0 
+}
+{ .mfb
+      nop.m            0
+(p10) fma.d.s1         f8   = f11,f1,f0 
+(p8)  br.ret.sptk      b0 
+};;
+//    If not a unnorm and not an big int, nan,or +/-inf convert signficand
+//    back to f8.
+//    If not a unorm  and a big int, nan, or +/-inf, return fnorm'd x 
+//    If not a unorm, Return
+//    If unnorm, get the exponent again - perhaps it wasn't a denorm. 
+{ .mfb
+(p7)  getf.exp         TRUNC_GR_signexp  = f11
+(p7)  fcvt.fx.trunc.s1 f12   = f11 
+      nop.b 0
+};;
+{ .mfb
+      and              TRUNC_GR_exponent = TRUNC_GR_signexp, TRUNC_GR_expmask
+      fcmp.lt.unc.s1   p9,p0 = f8,f0
+      nop.b            0
+};;
+{ .mfb
+      cmp.ge.unc       p10,p11 = TRUNC_GR_exponent, TRUNC_GR_bigexp
+      nop.f            0
+      nop.b            0
+};;
+// If a unnorm, check to see if value is already a big int. 
+{ .mfb
+      nop.m 0
+(p11) fcvt.xf          f8   = f12 
+      nop.b 0
+}
+{ .mfi
+      nop.m 0
+(p10) fma.d.s1         f8   = f11,f1,f0 
+      nop.i 0
+};;
+{ .mfb
+      nop.m 0
+(p9)  fmerge.ns        f8   = f1,f8 
+      br.ret.sptk      b0 
+};;
+// If so return it. Otherwise, return (fcvt.xf(fcvt.fx.trunc(x)))
+// Make sure the result is negative if it should be - that is
+// negative(denormal) -> -0.
+.endp trunc
+ASM_SIZE_DIRECTIVE(trunc)