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.file "ldexpf.s"
// Copyright (c) 2000, 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// 4/04/00 Unwind support added// 5/22/00 rewritten to not take swa and be a little faster// 8/15/00 Bundle added after call to __libm_error_support to properly// set [the previously overwritten] GR_Parameter_RESULT.//12/07/00 Removed code that prevented call to __libm_error_support.// Stored r33 instead of f9 as Parameter 2 for call to // __libm_error_support.//// API//==============================================================// float = ldexpf (float x, int n) // input floating point f8 and integer r33// output floating point f8//// returns x* 2**n computed by exponent // manipulation rather than by actually performing an // exponentiation or a multiplication.//// Overview of operation//==============================================================// ldexpf:// p7 is set if x is nan, inf, zero; go to x_nan_inf_zero
// sign extend r33// norm_f8 = fnorm(f8)// get exponent of norm_f8// add to r33 to get new exponent// p6, new_exponent > 103fe => overflow// p7, new_exponent > fbcd => underflow// setf new_exponent, merge significand, normalize, return
ldexp_float_int_f9 = f10 ldexp_int_f9 = f11ldexp_max_exp = f12ldexp_neg_max_exp = f13ldexp_new_f9 = f14
LDEXP_BIG = f32LDEXP_NORM_F8 = f33LDEXP_FFFF = f34LDEXP_BIG_SIGN = f35LDEXP_13FFE = f36 LDEXP_INV_BIG_SIGN = f37
// general registers used// r32 has ar.pfs// r33 has input integer
ldexp_GR_signexp = r34ldexp_GR_13FFE = r35ldexp_GR_new_exponent = r36ldexp_GE_FBCD = r37ldexp_GR_17ones = r38
GR_SAVE_B0 = r39GR_SAVE_GP = r40GR_SAVE_PFS = r41
ldexp_GR_exponent = r42ldexp_GR_103FE = r43 ldexp_GR_FFFF = r44
GR_Parameter_X = r45GR_Parameter_Y = r46GR_Parameter_RESULT = r47ldexp_GR_tag = r48
.global ldexpf
// ===============================================================// LDEXPF// ===============================================================
.text.proc ldexpf.align 32
// Be sure to sign extend r33 because the// integer comes in as 32-bits
ldexpf:
// x NAN, INF, ZERO, +-
{ .mfi alloc r32=ar.pfs,1,12,4,0 fclass.m.unc p7,p0 = f8, 0xe7 //@qnan | @snan | @inf | @zero sxt4 r33 = r33 };;
{ .mfi nop.m 999 fnorm LDEXP_NORM_F8 = f8 nop.i 999}
{ .mbb nop.m 999(p7) br.cond.spnt LDEXP_X_NAN_INF_ZERO nop.b 999};;
// LDEXP_BIG gets a big number, enough to overflow an frcpa// but not take an architecturally mandated swa.// We construct this constant rather than load it.
{ .mlx mov ldexp_GR_17ones = 0x1FFFF movl ldexp_GR_FFFF = 0xffffffffffffffff }{ .mfi addl ldexp_GR_13FFE = 0x13ffe, r0 nop.f 999 nop.i 999 };;
{ .mmb setf.exp LDEXP_13FFE = ldexp_GR_13FFE setf.sig LDEXP_FFFF = ldexp_GR_FFFF nop.b 999 };;
{ .mfi nop.m 999 fmerge.se LDEXP_BIG = LDEXP_13FFE, LDEXP_FFFF nop.i 999}
// Put the absolute normalized exponent in ldexp_GR_new_exponent// Assuming that the input int is in r33.// ldexp_GR_new_exponent gets the input int + the exponent of the input double
{ .mfi getf.exp ldexp_GR_signexp = LDEXP_NORM_F8 nop.f 999 nop.i 999 };;
{ .mii nop.m 999 nop.i 999 and ldexp_GR_exponent = ldexp_GR_signexp, ldexp_GR_17ones };;
// HUGE// Put big number in ldexp_GR_103FE// If ldexp_GR_new_exponent is bigger than ldexp_GR_103FE// Return a big number of the same sign // double: largest double exponent is 7fe (double-biased)// 103fe (register-biased)// f11 gets the big value in f9 with the f8 sign// For single,// single: largest single exponent is fe (single-biased)// fe - 7f + ffff = 1007e
{ .mii add ldexp_GR_new_exponent = ldexp_GR_exponent, r33 addl ldexp_GR_103FE = 0x1007e, r0 nop.i 999};;
{ .mfi setf.exp f12 = ldexp_GR_new_exponent nop.f 999 cmp.gt.unc p6,p0 = ldexp_GR_new_exponent, ldexp_GR_103FE };;
{ .mfb nop.m 999(p6) fmerge.s LDEXP_BIG_SIGN = f8, LDEXP_BIG nop.b 999 };;
{ .mfi nop.m 999(p6) fma.s f12 = LDEXP_BIG_SIGN, LDEXP_BIG, f0 (p6) mov ldexp_GR_tag = 148 }
{ .mib nop.m 999 nop.i 999(p6) br.spnt LDEXP_HUGE };;
// TINY// Put a small number in ldexp_GE_FBCD// If ldexp_GR_new_exponent is less than ldexp_GE_FBCD// Return a small number of the same sign // double:// 0xfbcd is -1074 unbiased, which is the exponent// of the smallest double denormal// single// 0xff6a is -149 unbiased which is the exponent// of the smallest single denormal//// Take the large value in f9 and put in f10 with// the sign of f8. Then take reciprocal in f11
{ .mfi addl ldexp_GE_FBCD = 0xff6a, r0 nop.f 999 nop.i 999};;
{ .mfi nop.m 999 nop.f 999 cmp.lt.unc p7,p0 = ldexp_GR_new_exponent, ldexp_GE_FBCD };;
{ .mfi nop.m 999(p7) fmerge.s LDEXP_BIG_SIGN = f8, LDEXP_BIG nop.i 999};;
{ .mfi nop.m 999(p7) frcpa.s1 LDEXP_INV_BIG_SIGN,p10 = f1,LDEXP_BIG_SIGN nop.i 999 };;
{ .mfi nop.m 999(p7) fnorm.s f12 = LDEXP_INV_BIG_SIGN (p7) mov ldexp_GR_tag = 149 }{ .mib nop.m 999 nop.i 999(p7) br.spnt LDEXP_TINY };;
// CALCULATION// Put exponent of answer in f12// f10 has the normalized f8// f13 = exp(f12) sig(f10)// f14 = sign(f8) expsig(f13)
{ .mfi nop.m 999 fmerge.se f13 = f12,LDEXP_NORM_F8 nop.i 999 };;
{ .mfi nop.m 999 fmerge.s f14 = f8,f13 nop.i 999 };;
{ .mfb nop.m 999 fnorm.s f8 = f14 br.ret.sptk b0 };;
LDEXP_N_NAN_INF:
// Is n a NAN?{ .mfi nop.m 999(p0) fclass.m.unc p6,p0 = f9, 0xc3 //@snan | @qnan nop.i 999 };;
{ .mfi nop.m 999(p6) fma.s f8 = f8,f9,f0 nop.i 999}
// Is n +INF?{ .mfi nop.m 999(p0) fclass.m.unc p7,p0 = f9, 0x21 //@inf | @pos nop.i 999 };;
{ .mfi nop.m 999(p7) fma.s f8 = f8,f9,f0 nop.i 999}
// Is n -inf?{ .mfi nop.m 999 fclass.m.unc p8,p9 = f9, 0x22 //@inf | @neg nop.i 999};;
{ .mfb nop.m 999(p8) frcpa f8,p6 = f8,f9 br.ret.sptk b0 };;
LDEXP_X_NAN_INF_ZERO:
{ .mfb nop.m 999 fnorm.s f8 = f8 // quietize br.ret.sptk b0 };;
.endp ldexpf
.proc __libm_error_region__libm_error_region:LDEXP_HUGE: LDEXP_TINY: .prologue{ .mfi add GR_Parameter_Y=-32,sp // Parameter 2 value nop.f 0.save ar.pfs,GR_SAVE_PFS mov GR_SAVE_PFS=ar.pfs // Save ar.pfs}{ .mfi.fframe 64 add sp=-64,sp // Create new stack nop.f 0 mov GR_SAVE_GP=gp // Save gp};;
{ .mmi st8 [GR_Parameter_Y] = r33,16 // STORE Parameter 2 on stack add GR_Parameter_X = 16,sp // Parameter 1 address.save b0, GR_SAVE_B0 mov GR_SAVE_B0=b0 // Save b0};;
.body{ .mib stfs [GR_Parameter_X] = f8 // STORE Parameter 1 on stack add GR_Parameter_RESULT = 0,GR_Parameter_Y // Parameter 3 address nop.b 0 }{ .mib stfs [GR_Parameter_Y] = f12 // STORE Parameter 3 on stack add GR_Parameter_Y = -16,GR_Parameter_Y br.call.sptk b0=__libm_error_support# // Call error handling function
};;
{ .mmi nop.m 0 nop.m 0 add GR_Parameter_RESULT = 48,sp};;
{ .mmi ldfs f8 = [GR_Parameter_RESULT] // Get return result off stack.restore add sp = 64,sp // Restore stack pointer mov b0 = GR_SAVE_B0 // Restore return address};;
{ .mib mov gp = GR_SAVE_GP // Restore gp mov ar.pfs = GR_SAVE_PFS // Restore ar.pfs br.ret.sptk b0 // Return};;
.endp __libm_error_region
.type __libm_error_support#,@function
.global __libm_error_support#
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