4 // Copyright (c) 2000 - 2003, Intel Corporation
5 // All rights reserved.
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9 // modification, are permitted provided that the following conditions are
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20 // products derived from this software without specific prior written
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37 // http://www.intel.com/software/products/opensource/libraries/num.htm.
39 //*********************************************************************
42 // 02/02/00 Initial version
43 // 04/04/00 Unwind support added
44 // 08/15/00 Bundle added after call to __libm_error_support to properly
45 // set [the previously overwritten] GR_Parameter_RESULT.
46 // 05/20/02 Cleaned up namespace and sf0 syntax
47 // 02/10/03 Reordered header: .section, .global, .proc, .align
49 //*********************************************************************
51 // Function: Combined sqrtf(x), where
53 // sqrtf(x) = |x, for single precision x values
55 //********************************************************************
57 // Accuracy: Correctly Rounded
59 //********************************************************************
63 // Floating-Point Registers: f8 (Input and Return Value)
66 // General Purpose Registers:
68 // r37-r40 (Used to pass arguments to error handling routine)
70 // Predicate Registers: p6, p7, p8
72 //********************************************************************
74 // IEEE Special Conditions:
76 // All faults and exceptions should be raised correctly.
80 // sqrtf(negative) = QNaN and error handling is called
82 //********************************************************************
86 // Modified Newton-Raphson Algorithm
88 //********************************************************************
97 GR_Parameter_RESULT = r39
98 GR_Parameter_TAG = r40
106 GLOBAL_IEEE754_ENTRY(sqrtf)
108 // BEGIN SINGLE PRECISION MINIMUM LATENCY SQUARE ROOT ALGORITHM
109 alloc r32= ar.pfs,0,5,4,0
110 // exponent of +1/2 in r2
120 // y0 = 1/sqrt(a) in f7
121 fclass.m.unc p7,p8 = f8,0x3A
125 // Make a copy of x just in case
131 // H0 = 1/2 * y0 in f9
132 (p6) fma.s1 f9=f12,f7,f0
138 (p6) fma.s1 f7=f8,f7,f0
143 // d = 1/2 - S0 * H0 in f10
144 (p6) fnma.s1 f10=f7,f9,f12
149 // 3/2 = 1 + 1/2 in f12
150 (p6) fma.s1 f12=f12,f1,f1
155 // e = 1 + 3/2 * d in f12
156 (p6) fma.s1 f12=f12,f10,f1
161 // T0 = d * S0 in f11
162 (p6) fma.s1 f11=f10,f7,f0
167 // G0 = d * H0 in f10
168 (p6) fma.s1 f10=f10,f9,f0
173 // S1 = S0 + e * T0 in f7
174 (p6) fma.s.s1 f7=f12,f11,f7
179 // H1 = H0 + e * G0 in f12
180 (p6) fma.s1 f12=f12,f10,f9
185 // d1 = a - S1 * S1 in f9
186 (p6) fnma.s1 f9=f7,f7,f8
191 // S = S1 + d1 * H1 in f7
192 (p6) fma.s.s0 f8=f9,f12,f7
193 (p6) br.ret.sptk b0 ;;
194 // END SINGLE PRECISION MINIMUM LATENCY SQUARE ROOT ALGORITHM
198 (p8) br.ret.sptk b0 ;;
201 // This branch includes all those special values that are not negative,
202 // with the result equal to frcpa(x)
204 GLOBAL_IEEE754_END(sqrtf)
205 libm_alias_float_other (__sqrt, sqrt)
208 LOCAL_LIBM_ENTRY(__libm_error_region)
211 add GR_Parameter_Y=-32,sp // Parameter 2 value
212 mov GR_Parameter_TAG = 50
213 .save ar.pfs,GR_SAVE_PFS
214 mov GR_SAVE_PFS=ar.pfs // Save ar.pfs
218 add sp=-64,sp // Create new stack
220 mov GR_SAVE_GP=gp // Save gp
223 stfs [GR_Parameter_Y] = FR_Y,16 // Store Parameter 2 on stack
224 add GR_Parameter_X = 16,sp // Parameter 1 address
226 mov GR_SAVE_B0=b0 // Save b0
230 stfs [GR_Parameter_X] = FR_X // Store Parameter 1 on stack
231 add GR_Parameter_RESULT = 0,GR_Parameter_Y
232 nop.b 0 // Parameter 3 address
235 stfs [GR_Parameter_Y] = FR_RESULT // Store Parameter 3 on stack
236 add GR_Parameter_Y = -16,GR_Parameter_Y
237 br.call.sptk b0=__libm_error_support# // Call error handling function
242 add GR_Parameter_RESULT = 48,sp
245 ldfs f8 = [GR_Parameter_RESULT] // Get return result off stack
247 add sp = 64,sp // Restore stack pointer
248 mov b0 = GR_SAVE_B0 // Restore return address
251 mov gp = GR_SAVE_GP // Restore gp
252 mov ar.pfs = GR_SAVE_PFS // Restore ar.pfs
253 br.ret.sptk b0 // Return
256 LOCAL_LIBM_END(__libm_error_region)
259 .type __libm_error_support#,@function
260 .global __libm_error_support#