1 | /* |
2 | * Public domain. |
3 | */ |
4 | |
5 | #include <machine/asm.h> |
6 | #include <libm-alias-finite.h> |
7 | |
8 | .section .rodata |
9 | |
10 | .align ALIGNARG(4) |
11 | .type zero_nan,@object |
12 | zero_nan: |
13 | .double 0.0 |
14 | nan: .byte 0, 0, 0, 0, 0, 0, 0xff, 0x7f |
15 | .byte 0, 0, 0, 0, 0, 0, 0, 0x80 |
16 | .byte 0, 0, 0, 0, 0, 0, 0xff, 0x7f |
17 | ASM_SIZE_DIRECTIVE(zero_nan) |
18 | |
19 | |
20 | #ifdef PIC |
21 | # define MO(op) op##(%rip) |
22 | #else |
23 | # define MO(op) op |
24 | #endif |
25 | |
26 | .text |
27 | ENTRY(__ieee754_scalbl) |
28 | fldt 24(%rsp) |
29 | fxam |
30 | fnstsw |
31 | fldt 8(%rsp) |
32 | andl $0x4700, %eax |
33 | cmpl $0x0700, %eax |
34 | je 1f |
35 | andl $0x4500, %eax |
36 | cmpl $0x0100, %eax |
37 | je 2f |
38 | fxam |
39 | fnstsw |
40 | andl $0x4500, %eax |
41 | cmpl $0x0100, %eax |
42 | je 2f |
43 | fld %st(1) |
44 | frndint |
45 | fcomip %st(2), %st |
46 | jne 4f |
47 | fscale |
48 | fstp %st(1) |
49 | ret |
50 | |
51 | /* y is -inf */ |
52 | 1: fxam |
53 | fnstsw |
54 | movl 16(%rsp), %edx |
55 | shrl $5, %eax |
56 | fstp %st |
57 | fstp %st |
58 | andl $0x8000, %edx |
59 | andl $0x0228, %eax |
60 | cmpl $0x0028, %eax |
61 | je 4f |
62 | andl $8, %eax |
63 | shrl $11, %edx |
64 | addl %edx, %eax |
65 | #ifdef PIC |
66 | lea zero_nan(%rip),%rdx |
67 | fldl (%rdx,%rax,1) |
68 | #else |
69 | fldl zero_nan(%rax, 1) |
70 | #endif |
71 | ret |
72 | |
73 | /* The result is NaN; raise an exception for sNaN arguments. */ |
74 | 2: faddp |
75 | ret |
76 | |
77 | /* Return NaN and raise the invalid exception. */ |
78 | 4: fstp %st |
79 | fstp %st |
80 | fldz |
81 | fdiv %st |
82 | ret |
83 | END(__ieee754_scalbl) |
84 | libm_alias_finite (__ieee754_scalbl, __scalbl) |
85 | |