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//.file "ldexpl.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
// 1/26/01 ldexpl completely reworked and now standalone version
//
// API
//==============================================================
// double-extended = ldexpl (double-extended x, int n)
// input floating point f8 and int n (r34)
// output floating point f8
//
// Returns x* 2**n using an fma and detects overflow
// and underflow.
//
//
#include "libm_support.h"
FR_Big = f6
FR_NBig = f7
FR_Floating_X = f8
FR_Result = f8
FR_Result2 = f9
FR_Result3 = f11
FR_Norm_X = f12
FR_Two_N = f14
FR_Two_to_Big = f15
GR_N_Biased = r15
GR_Big = r16
GR_NBig = r17
GR_Scratch = r18
GR_Scratch1 = r19
GR_Bias = r20
GR_N_as_int = r21
GR_SAVE_B0 = r32
GR_SAVE_GP = r33
GR_SAVE_PFS = r34
GR_Parameter_X = r35
GR_Parameter_Y = r36
GR_Parameter_RESULT = r37
GR_Tag = r38
.align 32
.global ldexpl
.section .text
.proc ldexpl
.align 32
ldexpl:
//
// Is x NAN, INF, ZERO, +-?
// Build the exponent Bias
//
{ .mfi
alloc r32=ar.pfs,2,1,4,0
fclass.m.unc p7,p0 = FR_Floating_X, 0xe7 //@snan | @qnan | @inf | @zero
addl GR_Bias = 0x0FFFF,r0
}
//
// Sign extend input
// Is N zero?
// Normalize x
//
{ .mfi
cmp.eq.unc p6,p0 = r34,r0
fnorm.s1 FR_Norm_X = FR_Floating_X
sxt4 GR_N_as_int = r34
}
;;
//
// Normalize x
// Branch and return special values.
// Create -35000
// Create 35000
//
{ .mfi
addl GR_Big = 35000,r0
nop.f 0
add GR_N_Biased = GR_Bias,GR_N_as_int
}
{ .mfb
addl GR_NBig = -35000,r0
(p7) fma.s0 FR_Result = FR_Floating_X,f1, f0
(p7) br.ret.spnt b0
};;
//
// Build the exponent Bias
// Return x when N = 0
//
{ .mfi
setf.exp FR_Two_N = GR_N_Biased
nop.f 0
addl GR_Scratch1 = 0x063BF,r0
}
{ .mfb
addl GR_Scratch = 0x019C3F,r0
(p6) fma.s0 FR_Result = FR_Floating_X,f1, f0
(p6) br.ret.spnt b0
};;
//
// Create 2*big
// Create 2**-big
// Is N > 35000
// Is N < -35000
// Raise Denormal operand flag with compare
// Main path, create 2**N
//
{ .mfi
setf.exp FR_NBig = GR_Scratch1
nop.f 0
cmp.ge.unc p6, p0 = GR_N_as_int, GR_Big
}
{ .mfi
setf.exp FR_Big = GR_Scratch
fcmp.ge.s0 p0,p11 = FR_Floating_X,f0
cmp.le.unc p8, p0 = GR_N_as_int, GR_NBig
};;
//
// Adjust 2**N if N was very small or very large
//
{ .mfi
nop.m 0
(p6) fma.s1 FR_Two_N = FR_Big,f1,f0
nop.i 0
}
{ .mlx
nop.m 999
(p0) movl GR_Scratch = 0x0000000000033FFF
};;
{ .mfi
nop.m 0
(p8) fma.s1 FR_Two_N = FR_NBig,f1,f0
nop.i 0
}
{ .mlx
nop.m 999
(p0) movl GR_Scratch1= 0x0000000000013FFF
};;
// Set up necessary status fields
//
// S0 user supplied status
// S2 user supplied status + WRE + TD (Overflows)
// S3 user supplied status + FZ + TD (Underflows)
//
{ .mfi
nop.m 999
(p0) fsetc.s3 0x7F,0x41
nop.i 999
}
{ .mfi
nop.m 999
(p0) fsetc.s2 0x7F,0x42
nop.i 999
};;
//
// Do final operation
//
{ .mfi
setf.exp FR_NBig = GR_Scratch
fma.s0 FR_Result = FR_Two_N,FR_Norm_X,f0
nop.i 999
}
{ .mfi
nop.m 999
fma.s3 FR_Result3 = FR_Two_N,FR_Norm_X,f0
nop.i 999
};;
{ .mfi
setf.exp FR_Big = GR_Scratch1
fma.s2 FR_Result2 = FR_Two_N,FR_Norm_X,f0
nop.i 999
};;
// Check for overflow or underflow.
// Restore s3
// Restore s2
//
{ .mfi
nop.m 0
fsetc.s3 0x7F,0x40
nop.i 999
}
{ .mfi
nop.m 0
fsetc.s2 0x7F,0x40
nop.i 999
};;
//
// Is the result zero?
//
{ .mfi
nop.m 999
fclass.m.unc p6, p0 = FR_Result3, 0x007
nop.i 999
}
{ .mfi
addl GR_Tag = 144, r0
fcmp.ge.unc.s1 p7, p8 = FR_Result2 , FR_Big
nop.i 0
};;
//
// Detect masked underflow - Tiny + Inexact Only
//
{ .mfi
nop.m 999
(p6) fcmp.neq.unc.s1 p6, p0 = FR_Result , FR_Result2
nop.i 999
};;
//
// Is result bigger the allowed range?
// Branch out for underflow
//
{ .mfb
(p6) addl GR_Tag = 145, r0
(p8) fcmp.le.unc.s1 p9, p10 = FR_Result2 , FR_NBig
(p6) br.cond.spnt L(ldexpl_UNDERFLOW)
};;
//
// Branch out for overflow
//
{ .mbb
nop.m 0
(p7) br.cond.spnt L(ldexpl_OVERFLOW)
(p9) br.cond.spnt L(ldexpl_OVERFLOW)
};;
//
// Return from main path.
//
{ .mfb
nop.m 999
nop.f 0
br.ret.sptk b0;;
}
.endp ldexpl
ASM_SIZE_DIRECTIVE(ldexpl)
.proc __libm_error_region
__libm_error_region:
L(ldexpl_OVERFLOW):
L(ldexpl_UNDERFLOW):
//
// Get stack address of N
//
.prologue
{ .mfi
add GR_Parameter_Y=-32,sp
nop.f 0
.save ar.pfs,GR_SAVE_PFS
mov GR_SAVE_PFS=ar.pfs
}
//
// Adjust sp
//
{ .mfi
.fframe 64
add sp=-64,sp
nop.f 0
mov GR_SAVE_GP=gp
};;
//
// Store N on stack in correct position
// Locate the address of x on stack
//
{ .mmi
st8 [GR_Parameter_Y] = GR_N_as_int,16
add GR_Parameter_X = 16,sp
.save b0, GR_SAVE_B0
mov GR_SAVE_B0=b0
};;
//
// Store x on the stack.
// Get address for result on stack.
//
.body
{ .mib
stfe [GR_Parameter_X] = FR_Norm_X
add GR_Parameter_RESULT = 0,GR_Parameter_Y
nop.b 0
}
{ .mib
stfe [GR_Parameter_Y] = FR_Result
add GR_Parameter_Y = -16,GR_Parameter_Y
br.call.sptk b0=__libm_error_support#
};;
//
// Get location of result on stack
//
{ .mmi
nop.m 0
nop.m 0
add GR_Parameter_RESULT = 48,sp
};;
//
// Get the new result
//
{ .mmi
ldfe FR_Result = [GR_Parameter_RESULT]
.restore sp
add sp = 64,sp
mov b0 = GR_SAVE_B0
};;
//
// Restore gp, ar.pfs and return
//
{ .mib
mov gp = GR_SAVE_GP
mov ar.pfs = GR_SAVE_PFS
br.ret.sptk b0
};;
.endp __libm_error_region
ASM_SIZE_DIRECTIVE(__libm_error_region)
.type __libm_error_support#,@function
.global __libm_error_support#
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