4 // Copyright (c) 2000 - 2003, Intel Corporation
5 // All rights reserved.
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20 // products derived from this software without specific prior written
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40 //==============================================================
41 // 02/02/00 Initial version
42 // 06/13/00 Improved speed
43 // 06/27/00 Eliminated incorrect invalid flag setting
44 // 05/20/02 Cleaned up namespace and sf0 syntax
45 // 01/28/03 Improved performance
46 //==============================================================
49 //==============================================================
50 // double ceil(double x)
51 //==============================================================
53 // general input registers:
63 // floating-point registers:
72 // predicate registers used:
75 // Overview of operation
76 //==============================================================
77 // double ceil(double x)
78 // Return an integer value (represented as a double) that is the smallest
79 // value not less than x
80 // This is x rounded toward +infinity to an integral value.
81 // Inexact is set if x != ceil(x)
82 //==============================================================
85 // if the exponent is > 1003e => 3F(true) = 63(decimal)
86 // we have a significand of 64 bits 1.63-bits.
87 // If we multiply by 2^63, we no longer have a fractional part
88 // So input is an integer value already.
91 // if the exponent is >= 10033 => 34(true) = 52(decimal)
93 // we have a significand of 53 bits 1.52-bits. (implicit 1)
94 // If we multiply by 2^52, we no longer have a fractional part
95 // So input is an integer value already.
98 // if the exponent is > 10016 => 17(true) = 23(decimal)
99 // we have a significand of 24 bits 1.23-bits. (implicit 1)
100 // If we multiply by 2^23, we no longer have a fractional part
101 // So input is an integer value already.
105 GLOBAL_LIBM_ENTRY(ceil)
108 getf.exp rSignexp = f8 // Get signexp, recompute if unorm
109 fclass.m p7,p0 = f8, 0x0b // Test x unorm
110 addl rBigexp = 0x10033, r0 // Set exponent at which is integer
113 mov rM1 = -1 // Set all ones
114 fcvt.fx.trunc.s1 fXInt = f8 // Convert to int in significand
115 mov rExpMask = 0x1FFFF // Form exponent mask
120 mov rSignexpM1 = 0x2FFFF // Form signexp of -1
121 fcmp.lt.s1 p8,p9 = f8, f0 // Test x < 0
125 setf.sig fTmp = rM1 // Make const for setting inexact
126 fnorm.s1 fNormX = f8 // Normalize input
127 (p7) br.cond.spnt CEIL_UNORM // Branch if x unorm
132 // Return here from CEIL_UNORM
135 fclass.m p6,p0 = f8, 0x1e7 // Test x natval, nan, inf, 0
140 .pred.rel "mutex",p8,p9
143 (p8) fma.s1 fAdj = f0, f0, f0 // If x < 0, adjustment is 0
148 (p9) fma.s1 fAdj = f1, f1, f0 // If x > 0, adjustment is +1
155 fcvt.xf fPreResult = fXInt // trunc(x)
160 (p6) fma.d.s0 f8 = f8, f1, f0 // Result if x natval, nan, inf, 0
161 (p6) br.ret.spnt b0 // Exit if x natval, nan, inf, 0
166 and rExp = rSignexp, rExpMask // Get biased exponent
168 cmp.ge p7,p6 = rExp, rBigexp // Is |x| >= 2^52?
169 (p8) cmp.lt.unc p10,p0 = rSignexp, rSignexpM1 // Is -1 < x < 0?
173 // If -1 < x < 0, we turn off p6 and compute result as -0
175 (p10) cmp.ne p6,p0 = r0,r0
176 (p10) fmerge.s f8 = fNormX, f0
181 .pred.rel "mutex",p6,p7
184 (p6) fma.d.s0 f8 = fPreResult, f1, fAdj // Result if !int, |x| < 2^52
189 (p7) fma.d.s0 f8 = fNormX, f1, f0 // Result, if |x| >= 2^52
190 (p10) cmp.eq p6,p0 = r0,r0 // If -1 < x < 0, turn on p6 again
196 (p6) fcmp.eq.unc.s1 p8, p9 = fPreResult, fNormX // Is trunc(x) = x ?
203 (p9) fmpy.s0 fTmp = fTmp, fTmp // Dummy to set inexact
208 (p8) fma.d.s0 f8 = fNormX, f1, f0 // If x int, result normalized x
209 br.ret.sptk b0 // Exit main path, 0 < |x| < 2^52
217 getf.exp rSignexp = fNormX // Get signexp, recompute if unorm
218 fcmp.eq.s0 p7,p0 = f8, f0 // Dummy op to set denormal flag
219 br.cond.sptk CEIL_COMMON // Return to main path
223 GLOBAL_LIBM_END(ceil)
224 libm_alias_double_other (ceil, ceil)