1
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <malloc.h>
5 #include <string.h>
6
7 const unsigned int vec0[4]
8 = { 0x12345678, 0x11223344, 0x55667788, 0x87654321 };
9
10 const unsigned int vec1[4]
11 = { 0xABCDEF01, 0xAABBCCDD, 0xEEFF0011, 0x10FEDCBA };
12
13 const unsigned int vecZ[4]
14 = { 0, 0, 0, 0 };
15
do_fxsave(void * p)16 void do_fxsave ( void* p ) {
17 asm __volatile__("fxsave (%0)" : : "r" (p) : "memory" );
18 }
19
do_fxrstor(void * p)20 void do_fxrstor ( void* p ) {
21 asm __volatile__("fxrstor (%0)" : : "r" (p) : "memory" );
22 }
23
do_zeroise(void)24 void do_zeroise ( void )
25 {
26 asm __volatile__("finit");
27 asm __volatile__(
28 "fldz\n\t"
29 "fldz\n\t"
30 "fldz\n\t"
31 "fldz\n\t"
32 "fldz\n\t"
33 "fldz\n\t"
34 "fldz\n\t"
35 "fldz\n\t"
36 "finit\n");
37 asm __volatile__("movups vecZ, %xmm0");
38 asm __volatile__("movups vecZ, %xmm1");
39 asm __volatile__("movups vecZ, %xmm2");
40 asm __volatile__("movups vecZ, %xmm3");
41 asm __volatile__("movups vecZ, %xmm4");
42 asm __volatile__("movups vecZ, %xmm5");
43 asm __volatile__("movups vecZ, %xmm6");
44 asm __volatile__("movups vecZ, %xmm7");
45 asm __volatile__(
46 "pushl $0\n\t"
47 "ldmxcsr 0(%esp)\n\t"
48 "addl $4,%esp\n");
49 }
50
51 /* set up the FP and SSE state, and then dump it. */
do_setup_then_fxsave(void * p)52 void do_setup_then_fxsave ( void* p )
53 {
54 asm __volatile__("finit");
55 asm __volatile__("fldpi");
56 asm __volatile__("fld1");
57 asm __volatile__("fldln2");
58 asm __volatile__("fldlg2");
59 asm __volatile__("fld %st(3)");
60 asm __volatile__("fld %st(3)");
61 asm __volatile__("movups vec0, %xmm0");
62 asm __volatile__("movups vec1, %xmm1");
63 asm __volatile__("xorps %xmm2, %xmm2");
64 asm __volatile__("movaps %xmm2, %xmm3");
65 asm __volatile__("movaps %xmm2, %xmm4");
66 asm __volatile__("movaps %xmm2, %xmm5");
67 asm __volatile__("movaps %xmm2, %xmm6");
68 asm __volatile__("movaps %xmm1, %xmm7");
69 asm __volatile__("xorps %xmm0, %xmm7");
70 do_fxsave (p);
71 }
72
isFPLsbs(int i)73 int isFPLsbs ( int i )
74 {
75 int q;
76 q = 32; if (i == q || i == q+1) return 1;
77 q = 48; if (i == q || i == q+1) return 1;
78 q = 64; if (i == q || i == q+1) return 1;
79 q = 80; if (i == q || i == q+1) return 1;
80 q = 96; if (i == q || i == q+1) return 1;
81 q = 112; if (i == q || i == q+1) return 1;
82 q = 128; if (i == q || i == q+1) return 1;
83 q = 144; if (i == q || i == q+1) return 1;
84 return 0;
85 }
86
show(unsigned char * buf,int xx)87 void show ( unsigned char* buf, int xx )
88 {
89 int i;
90 for (i = 0; i < 512; i++) {
91 if ((i % 16) == 0)
92 printf("%3d ", i);
93 if (xx && isFPLsbs(i))
94 printf("xx ");
95 else
96 printf("%02x ", buf[i]);
97 if (i > 0 && ((i % 16) == 15))
98 printf("\n");
99 }
100 }
101
102
main(int argc,char ** argv)103 int main ( int argc, char** argv )
104 {
105 unsigned char* buf1 = memalign(16,512);
106 unsigned char* buf2 = memalign(16,512);
107 unsigned char* buf3 = memalign(16,512);
108 int xx = argc > 1;
109 printf("Re-run with any arg to suppress least-significant\n"
110 " 16 bits of FP numbers\n");
111 memset(buf1, 0x55, 512);
112 memset(buf2, 0x55, 512);
113 memset(buf3, 0x55, 512);
114
115 /* Load up x87/xmm state and dump it. */
116 do_setup_then_fxsave(buf1);
117 printf("\nBEFORE\n");
118 show(buf1, xx);
119
120 /* Zeroise x87/xmm state and dump it, to show that the
121 regs have been cleared out. */
122 do_zeroise();
123 do_fxsave(buf2);
124 printf("\nZEROED\n");
125 show(buf2, xx);
126
127 /* Reload x87/xmm state from buf1 and dump it in buf3. */
128 do_fxrstor(buf1);
129 do_fxsave(buf3);
130 printf("\nRESTORED\n");
131 show(buf3, xx);
132
133 free(buf1); free(buf2); free(buf3);
134
135 return 0;
136 }
137