File: | src/lib/libm/src/e_hypotf.c |
Warning: | line 29, column 48 Value stored to 'a' is never read |
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1 | /* e_hypotf.c -- float version of e_hypot.c. |
2 | * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. |
3 | */ |
4 | |
5 | /* |
6 | * ==================================================== |
7 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
8 | * |
9 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
10 | * Permission to use, copy, modify, and distribute this |
11 | * software is freely granted, provided that this notice |
12 | * is preserved. |
13 | * ==================================================== |
14 | */ |
15 | |
16 | #include "math.h" |
17 | #include "math_private.h" |
18 | |
19 | float |
20 | hypotf(float x, float y) |
21 | { |
22 | float a=x,b=y,t1,t2,yy1,y2,w; |
23 | int32_t j,k,ha,hb; |
24 | |
25 | GET_FLOAT_WORD(ha,x)do { ieee_float_shape_type gf_u; gf_u.value = (x); (ha) = gf_u .word; } while (0); |
26 | ha &= 0x7fffffff; |
27 | GET_FLOAT_WORD(hb,y)do { ieee_float_shape_type gf_u; gf_u.value = (y); (hb) = gf_u .word; } while (0); |
28 | hb &= 0x7fffffff; |
29 | if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;} |
Value stored to 'a' is never read | |
30 | SET_FLOAT_WORD(a,ha)do { ieee_float_shape_type sf_u; sf_u.word = (ha); (a) = sf_u .value; } while (0); /* a <- |a| */ |
31 | SET_FLOAT_WORD(b,hb)do { ieee_float_shape_type sf_u; sf_u.word = (hb); (b) = sf_u .value; } while (0); /* b <- |b| */ |
32 | if((ha-hb)>0xf000000) {return a+b;} /* x/y > 2**30 */ |
33 | k=0; |
34 | if(ha > 0x58800000) { /* a>2**50 */ |
35 | if(ha >= 0x7f800000) { /* Inf or NaN */ |
36 | w = a+b; /* for sNaN */ |
37 | if(ha == 0x7f800000) w = a; |
38 | if(hb == 0x7f800000) w = b; |
39 | return w; |
40 | } |
41 | /* scale a and b by 2**-68 */ |
42 | ha -= 0x22000000; hb -= 0x22000000; k += 68; |
43 | SET_FLOAT_WORD(a,ha)do { ieee_float_shape_type sf_u; sf_u.word = (ha); (a) = sf_u .value; } while (0); |
44 | SET_FLOAT_WORD(b,hb)do { ieee_float_shape_type sf_u; sf_u.word = (hb); (b) = sf_u .value; } while (0); |
45 | } |
46 | if(hb < 0x26800000) { /* b < 2**-50 */ |
47 | if(hb <= 0x007fffff) { /* subnormal b or 0 */ |
48 | if(hb==0) return a; |
49 | SET_FLOAT_WORD(t1,0x7e800000)do { ieee_float_shape_type sf_u; sf_u.word = (0x7e800000); (t1 ) = sf_u.value; } while (0); /* t1=2^126 */ |
50 | b *= t1; |
51 | a *= t1; |
52 | k -= 126; |
53 | } else { /* scale a and b by 2^68 */ |
54 | ha += 0x22000000; /* a *= 2^68 */ |
55 | hb += 0x22000000; /* b *= 2^68 */ |
56 | k -= 68; |
57 | SET_FLOAT_WORD(a,ha)do { ieee_float_shape_type sf_u; sf_u.word = (ha); (a) = sf_u .value; } while (0); |
58 | SET_FLOAT_WORD(b,hb)do { ieee_float_shape_type sf_u; sf_u.word = (hb); (b) = sf_u .value; } while (0); |
59 | } |
60 | } |
61 | /* medium size a and b */ |
62 | w = a-b; |
63 | if (w>b) { |
64 | SET_FLOAT_WORD(t1,ha&0xfffff000)do { ieee_float_shape_type sf_u; sf_u.word = (ha&0xfffff000 ); (t1) = sf_u.value; } while (0); |
65 | t2 = a-t1; |
66 | w = sqrtf(t1*t1-(b*(-b)-t2*(a+t1))); |
67 | } else { |
68 | a = a+a; |
69 | SET_FLOAT_WORD(yy1,hb&0xfffff000)do { ieee_float_shape_type sf_u; sf_u.word = (hb&0xfffff000 ); (yy1) = sf_u.value; } while (0); |
70 | y2 = b - yy1; |
71 | SET_FLOAT_WORD(t1,ha+0x00800000)do { ieee_float_shape_type sf_u; sf_u.word = (ha+0x00800000); (t1) = sf_u.value; } while (0); |
72 | t2 = a - t1; |
73 | w = sqrtf(t1*yy1-(w*(-w)-(t1*y2+t2*b))); |
74 | } |
75 | if(k!=0) { |
76 | SET_FLOAT_WORD(t1,0x3f800000+(k<<23))do { ieee_float_shape_type sf_u; sf_u.word = (0x3f800000+(k<< 23)); (t1) = sf_u.value; } while (0); |
77 | return t1*w; |
78 | } else return w; |
79 | } |
80 | DEF_STD(hypotf)__asm__(".global " "hypotf" " ; " "hypotf" " = " "_libm_hypotf" ); |