m68k/fpsp040/slog2.S

4 |       The entry point slog10 computes the base-10
8 |	sLog2 and sLog2d are the base-2 analogues.
10 |       INPUT:	Double-extended value in memory location pointed to
13 |       OUTPUT: log_10(X) or log_2(X) returned in floating-point
18 |		to 53 bits if the result is subsequently rounded
19 |		to double precision. The result is provably monotonic
22 |       SPEED:	Two timings are measured, both in the copy-back mode.
33 |                 flag. Otherwise, save FPCR in D1; set FpCR to default.
34 |       Notes:    Default means round-to-nearest mode, no floating-point
37 |       Step 1.   Call slognd to obtain Y = log(X), the natural log of X.
48 |                 flag. Otherwise, save FPCR in D1; set FpCR to default.
49 |       Notes:    Default means round-to-nearest mode, no floating-point
52 |       Step 1.   Call sLogN to obtain Y = log(X), the natural log of X.
62 |                 flag. Otherwise, save FPCR in D1; set FpCR to default.
63 |       Notes:    Default means round-to-nearest mode, no floating-point
66 |       Step 1.   Call slognd to obtain Y = log(X), the natural log of X.
77 |                 flag. Otherwise, save FPCR in D1; set FpCR to default.
78 |       Notes:    Default means round-to-nearest mode, no floating-point
82 |                 go to Step 3.
87 |            2.3  Return ans := convert-to-double-extended(k).
89 |       Step 3.   Call sLogN to obtain Y = log(X), the natural log of X.
102 |SLOG2    idnt    2,1 | Motorola 040 Floating Point Software Package
117 |--entry point for Log10(X), X is denormalized
120 	movel		%d1,-(%sp)
129 |--entry point for Log10(X), X is normalized
133 	movel		%d1,-(%sp)
143 |--entry point for Log2(X), X is denormalized
147 	movel		%d1,-(%sp)
156 |--entry point for Log2(X), X is normalized
168 |--X = 2^k.
177 	movel		%d1,-(%sp)