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glibc/sysdeps/ia64/fpu/e_scalb.S
Mike Frysinger c70a4b1db0 ia64: relocate out of ports/ subdir
2014-02-16 01:12:38 -05:00

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.file "scalb.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
//==============================================================
// 02/02/00 Initial version
// 01/26/01 Scalb completely reworked and now standalone version
// 05/20/02 Cleaned up namespace and sf0 syntax
// 02/10/03 Reordered header: .section, .global, .proc, .align
// 08/06/03 Improved performance
//
// API
//==============================================================
// double = scalb (double x, double n)
// input floating point f8 and floating point f9
// output floating point f8
//
// int_type = 0 if int is 32 bits
// int_type = 1 if int is 64 bits
//
// Returns x* 2**n using an fma and detects overflow
// and underflow.
//
//
// Strategy:
// Compute biased exponent of result exp_Result = N + exp_X
// Break into ranges:
// exp_Result > 0x103fe -> Certain overflow
// exp_Result = 0x103fe -> Possible overflow
// 0x0fc01 <= exp_Result < 0x103fe -> No over/underflow (main path)
// 0x0fc01 - 52 <= exp_Result < 0x0fc01 -> Possible underflow
// exp_Result < 0x0fc01 - 52 -> Certain underflow
FR_Big = f6
FR_NBig = f7
FR_Floating_X = f8
FR_Result = f8
FR_Floating_N = f9
FR_Result2 = f9
FR_Result3 = f10
FR_Norm_X = f11
FR_Two_N = f12
FR_N_float_int = f13
FR_Norm_N = f14
GR_neg_ov_limit= r14
GR_big_exp = r14
GR_N_Biased = r15
GR_Big = r16
GR_exp_Result = r18
GR_pos_ov_limit= r19
GR_exp_sure_ou = r19
GR_Bias = r20
GR_N_as_int = r21
GR_signexp_X = r22
GR_exp_X = r23
GR_exp_mask = r24
GR_max_exp = r25
GR_min_exp = r26
GR_min_den_exp = r27
GR_Scratch = r28
GR_signexp_N = r29
GR_exp_N = r30
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
.section .text
GLOBAL_IEEE754_ENTRY(scalb)
//
// Is x NAN, INF, ZERO, +-?
// Build the exponent Bias
//
{ .mfi
getf.exp GR_signexp_N = FR_Floating_N // Get signexp of n
fclass.m p6,p0 = FR_Floating_X, 0xe7 // @snan | @qnan | @inf | @zero
mov GR_Bias = 0x0ffff
}
{ .mfi
mov GR_Big = 35000 // If N this big then certain overflow
fcvt.fx.trunc.s1 FR_N_float_int = FR_Floating_N // Get N in significand
nop.i 0
}
;;
{ .mfi
getf.exp GR_signexp_X = FR_Floating_X // Get signexp of x
fclass.m p7,p0 = FR_Floating_N, 0x0b // Test for n=unorm
nop.i 0
}
//
// Normalize n
//
{ .mfi
mov GR_exp_mask = 0x1ffff // Exponent mask
fnorm.s1 FR_Norm_N = FR_Floating_N
nop.i 0
}
;;
//
// Is n NAN, INF, ZERO, +-?
//
{ .mfi
mov GR_big_exp = 0x1003e // Exponent at which n is integer
fclass.m p9,p0 = FR_Floating_N, 0xe7 // @snan | @qnan | @inf | @zero
mov GR_max_exp = 0x103fe // Exponent of maximum double
}
//
// Normalize x
//
{ .mfb
nop.m 0
fnorm.s1 FR_Norm_X = FR_Floating_X
(p7) br.cond.spnt SCALB_N_UNORM // Branch if n=unorm
}
;;
SCALB_COMMON1:
// Main path continues. Also return here from u=unorm path.
// Handle special cases if x = Nan, Inf, Zero
{ .mfb
nop.m 0
fcmp.lt.s1 p7,p0 = FR_Floating_N, f0 // Test N negative
(p6) br.cond.spnt SCALB_NAN_INF_ZERO
}
;;
// Handle special cases if n = Nan, Inf, Zero
{ .mfi
getf.sig GR_N_as_int = FR_N_float_int // Get n from significand
fclass.m p8,p0 = FR_Floating_X, 0x0b // Test for x=unorm
mov GR_exp_sure_ou = 0x1000e // Exp_N where x*2^N sure over/under
}
{ .mfb
mov GR_min_exp = 0x0fc01 // Exponent of minimum double
fcvt.xf FR_N_float_int = FR_N_float_int // Convert N to FP integer
(p9) br.cond.spnt SCALB_NAN_INF_ZERO
}
;;
{ .mmi
and GR_exp_N = GR_exp_mask, GR_signexp_N // Get exponent of N
(p7) sub GR_Big = r0, GR_Big // Limit for N
nop.i 0
}
;;
{ .mib
cmp.lt p9,p0 = GR_exp_N, GR_big_exp // N possible non-integer?
cmp.ge p6,p0 = GR_exp_N, GR_exp_sure_ou // N certain over/under?
(p8) br.cond.spnt SCALB_X_UNORM // Branch if x=unorm
}
;;
SCALB_COMMON2:
// Main path continues. Also return here from x=unorm path.
// Create biased exponent for 2**N
{ .mmi
(p6) mov GR_N_as_int = GR_Big // Limit N
;;
add GR_N_Biased = GR_Bias,GR_N_as_int
nop.i 0
}
;;
{ .mfi
setf.exp FR_Two_N = GR_N_Biased // Form 2**N
(p9) fcmp.neq.unc.s1 p9,p0 = FR_Norm_N, FR_N_float_int // Test if N an integer
and GR_exp_X = GR_exp_mask, GR_signexp_X // Get exponent of X
}
;;
//
// Compute biased result exponent
// Branch if N is not an integer
//
{ .mib
add GR_exp_Result = GR_exp_X, GR_N_as_int
mov GR_min_den_exp = 0x0fc01 - 52 // Exponent of min denorm dble
(p9) br.cond.spnt SCALB_N_NOT_INT
}
;;
//
// Raise Denormal operand flag with compare
// Do final operation
//
{ .mfi
cmp.lt p7,p6 = GR_exp_Result, GR_max_exp // Test no overflow
fcmp.ge.s0 p0,p11 = FR_Floating_X,FR_Floating_N // Dummy to set denorm
cmp.lt p9,p0 = GR_exp_Result, GR_min_den_exp // Test sure underflow
}
{ .mfb
nop.m 0
fma.d.s0 FR_Result = FR_Two_N,FR_Norm_X,f0
(p9) br.cond.spnt SCALB_UNDERFLOW // Branch if certain underflow
}
;;
{ .mib
(p6) cmp.gt.unc p6,p8 = GR_exp_Result, GR_max_exp // Test sure overflow
(p7) cmp.ge.unc p7,p9 = GR_exp_Result, GR_min_exp // Test no over/underflow
(p7) br.ret.sptk b0 // Return from main path
}
;;
{ .bbb
(p6) br.cond.spnt SCALB_OVERFLOW // Branch if certain overflow
(p8) br.cond.spnt SCALB_POSSIBLE_OVERFLOW // Branch if possible overflow
(p9) br.cond.spnt SCALB_POSSIBLE_UNDERFLOW // Branch if possible underflow
}
;;
// Here if possible underflow.
// Resulting exponent: 0x0fc01-52 <= exp_Result < 0x0fc01
SCALB_POSSIBLE_UNDERFLOW:
//
// Here if possible overflow.
// Resulting exponent: 0x103fe = exp_Result
SCALB_POSSIBLE_OVERFLOW:
// Set up necessary status fields
//
// S0 user supplied status
// S2 user supplied status + WRE + TD (Overflows)
// S3 user supplied status + FZ + TD (Underflows)
//
{ .mfi
mov GR_pos_ov_limit = 0x103ff // Exponent for positive overflow
fsetc.s3 0x7F,0x41
nop.i 0
}
{ .mfi
mov GR_neg_ov_limit = 0x303ff // Exponent for negative overflow
fsetc.s2 0x7F,0x42
nop.i 0
}
;;
//
// Do final operation with s2 and s3
//
{ .mfi
setf.exp FR_NBig = GR_neg_ov_limit
fma.d.s3 FR_Result3 = FR_Two_N,FR_Norm_X,f0
nop.i 0
}
{ .mfi
setf.exp FR_Big = GR_pos_ov_limit
fma.d.s2 FR_Result2 = FR_Two_N,FR_Norm_X,f0
nop.i 0
}
;;
// Check for overflow or underflow.
// Restore s3
// Restore s2
//
{ .mfi
nop.m 0
fsetc.s3 0x7F,0x40
nop.i 0
}
{ .mfi
nop.m 0
fsetc.s2 0x7F,0x40
nop.i 0
}
;;
//
// Is the result zero?
//
{ .mfi
nop.m 0
fclass.m p6, p0 = FR_Result3, 0x007
nop.i 0
}
{ .mfi
nop.m 0
fcmp.ge.s1 p7, p8 = FR_Result2 , FR_Big
nop.i 0
}
;;
//
// Detect masked underflow - Tiny + Inexact Only
//
{ .mfi
nop.m 0
(p6) fcmp.neq.unc.s1 p6, p0 = FR_Result , FR_Result2
nop.i 0
}
;;
//
// Is result bigger the allowed range?
// Branch out for underflow
//
{ .mfb
nop.m 0
(p8) fcmp.le.unc.s1 p9, p10 = FR_Result2 , FR_NBig
(p6) br.cond.spnt SCALB_UNDERFLOW
}
;;
//
// Branch out for overflow
//
{ .bbb
(p7) br.cond.spnt SCALB_OVERFLOW
(p9) br.cond.spnt SCALB_OVERFLOW
br.ret.sptk b0 // Return from main path.
}
;;
// Here if result overflows
SCALB_OVERFLOW:
{ .mib
alloc r32=ar.pfs,3,0,4,0
addl GR_Tag = 53, r0 // Set error tag for overflow
br.cond.sptk __libm_error_region // Call error support for overflow
}
;;
// Here if result underflows
SCALB_UNDERFLOW:
{ .mib
alloc r32=ar.pfs,3,0,4,0
addl GR_Tag = 54, r0 // Set error tag for underflow
br.cond.sptk __libm_error_region // Call error support for underflow
}
;;
SCALB_NAN_INF_ZERO:
//
// Before entry, N has been converted to a fp integer in significand of
// FR_N_float_int
//
// Convert N_float_int to floating point value
//
{ .mfi
getf.sig GR_N_as_int = FR_N_float_int
fclass.m p6,p0 = FR_Floating_N, 0xc3 //@snan | @qnan
nop.i 0
}
{ .mfi
addl GR_Scratch = 1,r0
fcvt.xf FR_N_float_int = FR_N_float_int
nop.i 0
}
;;
{ .mfi
nop.m 0
fclass.m p7,p0 = FR_Floating_X, 0xc3 //@snan | @qnan
shl GR_Scratch = GR_Scratch,63
}
;;
{ .mfi
nop.m 0
fclass.m p8,p0 = FR_Floating_N, 0x21 // @inf
nop.i 0
}
{ .mfi
nop.m 0
fclass.m p9,p0 = FR_Floating_N, 0x22 // @-inf
nop.i 0
}
;;
//
// Either X or N is a Nan, return result and possible raise invalid.
//
{ .mfb
nop.m 0
(p6) fma.d.s0 FR_Result = FR_Floating_N,FR_Floating_X,f0
(p6) br.ret.spnt b0
}
;;
{ .mfb
nop.m 0
(p7) fma.d.s0 FR_Result = FR_Floating_N,FR_Floating_X,f0
(p7) br.ret.spnt b0
}
;;
//
// If N + Inf do something special
// For N = -Inf, create Int
//
{ .mfb
nop.m 0
(p8) fma.d.s0 FR_Result = FR_Floating_X, FR_Floating_N,f0
(p8) br.ret.spnt b0
}
{ .mfi
nop.m 0
(p9) fnma.d.s0 FR_Floating_N = FR_Floating_N, f1, f0
nop.i 0
}
;;
//
// If N==-Inf,return x/(-N)
//
{ .mfb
cmp.ne p7,p0 = GR_N_as_int,GR_Scratch
(p9) frcpa.s0 FR_Result,p0 = FR_Floating_X,FR_Floating_N
(p9) br.ret.spnt b0
}
;;
//
// Is N an integer.
//
{ .mfi
nop.m 0
(p7) fcmp.neq.unc.s1 p7,p0 = FR_Norm_N, FR_N_float_int
nop.i 0
}
;;
//
// If N not an int, return NaN and raise invalid.
//
{ .mfb
nop.m 0
(p7) frcpa.s0 FR_Result,p0 = f0,f0
(p7) br.ret.spnt b0
}
;;
//
// Always return x in other path.
//
{ .mfb
nop.m 0
fma.d.s0 FR_Result = FR_Floating_X,f1,f0
br.ret.sptk b0
}
;;
// Here if n not int
// Return NaN and raise invalid.
SCALB_N_NOT_INT:
{ .mfb
nop.m 0
frcpa.s0 FR_Result,p0 = f0,f0
br.ret.sptk b0
}
;;
// Here if n=unorm
SCALB_N_UNORM:
{ .mfb
getf.exp GR_signexp_N = FR_Norm_N // Get signexp of normalized n
fcvt.fx.trunc.s1 FR_N_float_int = FR_Norm_N // Get N in significand
br.cond.sptk SCALB_COMMON1 // Return to main path
}
;;
// Here if x=unorm
SCALB_X_UNORM:
{ .mib
getf.exp GR_signexp_X = FR_Norm_X // Get signexp of normalized x
nop.i 0
br.cond.sptk SCALB_COMMON2 // Return to main path
}
;;
GLOBAL_IEEE754_END(scalb)
LOCAL_LIBM_ENTRY(__libm_error_region)
//
// 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
stfd [GR_Parameter_Y] = FR_Norm_N,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
stfd [GR_Parameter_X] = FR_Norm_X
add GR_Parameter_RESULT = 0,GR_Parameter_Y
nop.b 0
}
{ .mib
stfd [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
add GR_Parameter_RESULT = 48,sp
nop.m 0
nop.i 0
};;
//
// Get the new result
//
{ .mmi
ldfd 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
};;
LOCAL_LIBM_END(__libm_error_region)
.type __libm_error_support#,@function
.global __libm_error_support#
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