show_fp_state.c revision c36ed7a14ec92dee029d0fa5918afc71a475432b
1 2#include <stdio.h> 3#include <assert.h> 4 5 6/* ------------------------------------------------- */ 7 8typedef unsigned char UChar; 9typedef unsigned short UShort; 10typedef unsigned int UInt; 11typedef unsigned long long int ULong; 12 13typedef signed char Char; 14typedef short Short; 15typedef int Int; 16typedef long long int Long; 17 18typedef 19 struct { 20 UShort env[14]; 21 UChar reg[80]; 22 } 23 Fpu_State; 24 25/* Offsets, in 16-bit ints, into the FPU environment (env) area. */ 26#define FP_ENV_CTRL 0 27#define FP_ENV_STAT 2 28#define FP_ENV_TAG 4 29#define FP_ENV_IP 6 /* and 7 */ 30#define FP_ENV_CS 8 31#define FP_ENV_OPOFF 10 /* and 11 */ 32#define FP_ENV_OPSEL 12 33#define FP_REG(ii) (10*(7-(ii))) 34 35/* Bitfield offsets for exceptions in the FPU status and control words. */ 36#define FP_E_INVAL 0 37#define FP_E_DENOR 1 38#define FP_E_DIVZ 2 39#define FP_E_OVERF 3 40#define FP_E_UNDER 4 41#define FP_E_LOS 5 42 43/* More bitfield offsets, but for the status word only. */ 44#define FP_E_STACKF 6 45#define FP_E_SUMMARY 7 46#define FP_F_C0 8 47#define FP_F_C1 9 48#define FP_F_C2 10 49#define FP_F_C3 14 50/* top-of-stack ptr is bits 13,12,11 of the word */ 51#define FP_F_TOS_LO 11 52#define FP_F_TOS_HI 13 53 54/* Register tags. */ 55#define FP_TAG_VALID 0 56#define FP_TAG_ZERO 1 57#define FP_TAG_SPEC 2 58#define FP_TAG_EMPTY 3 59 60char* fp_tag_names[4] 61 = { "Valid", "Zero", "Spec", "Empty" }; 62 63char* fp_exception_names[6] 64 = { "INVAL", "DENOR", "DIVZ", "OVERF", "UNDERF", "LOS" }; 65 66Fpu_State m_fpu_state; 67 68 69 70UInt fp_get_tos ( void ) 71{ 72 return (m_fpu_state.env[FP_ENV_STAT] >> FP_F_TOS_LO) & 7; 73} 74 75UInt fp_get_tag ( UInt regno ) 76{ 77 assert(!(regno < 0 || regno > 7)); 78 return (m_fpu_state.env[FP_ENV_TAG] >> (2*regno)) & 3; 79} 80 81UInt fp_get_statusword_flag ( UInt flagno ) 82{ 83 assert(!(flagno < 0 || flagno > 15)); 84 return (m_fpu_state.env[FP_ENV_STAT] >> flagno) & 0x1; 85} 86 87UInt fp_get_controlword_flag ( UInt flagno ) 88{ 89 assert(!(flagno < 0 || flagno > 15)); 90 return (m_fpu_state.env[FP_ENV_CTRL] >> flagno) & 0x1; 91} 92 93static 94void printFpuState ( void ) 95{ 96 Int i, j, k; 97 assert(sizeof(Fpu_State)==108); 98 for (i = 7; i >= 0; i--) { 99 printf ( " %s fpreg%d: 0x", 100 (UInt)i == fp_get_tos() ? "**" : " ", i ); 101 for (k = 0, j = FP_REG(i)+9; k < 10; k++,j--) 102 printf ( "%02x", (UInt)m_fpu_state.reg[j]); 103 printf ( " %5s ", fp_tag_names[fp_get_tag(i)] ); 104 printf("\n"); 105 //printf ( "%20.16e\n", fp_get_reg(i) ); 106 } 107 printf(" fctrl: 0x%04x masked: ", 108 (UInt)m_fpu_state.env[FP_ENV_CTRL] ); 109 for (i = FP_E_INVAL; i <= FP_E_LOS; i++) 110 if (fp_get_controlword_flag(i)) 111 printf ( "%s ", fp_exception_names[i] ); 112 printf ( "\n" ); 113 114 printf(" fstat: 0x%04x except:", 115 (UInt)m_fpu_state.env[FP_ENV_STAT] ); 116 for (i = FP_E_INVAL; i <= FP_E_LOS; i++) 117 if (fp_get_statusword_flag(i)) 118 printf ( "%s ", fp_exception_names[i] ); 119 printf ( " top: %d ", fp_get_tos() ); 120 printf ( "c3210: %d%d%d%d", 121 fp_get_statusword_flag(FP_F_C3), 122 fp_get_statusword_flag(FP_F_C2), 123 fp_get_statusword_flag(FP_F_C1), 124 fp_get_statusword_flag(FP_F_C0) ); 125 printf ( " STACKF: %d\n", fp_get_statusword_flag(FP_E_STACKF) ); 126 127 printf(" ftag: 0x%04x ", (UInt)m_fpu_state.env[FP_ENV_TAG] ); 128 for (i = 7; i >= 0; i--) 129 printf ( "%d:%s ", i, fp_tag_names[fp_get_tag(i)] ); 130 printf("\n"); 131 132 printf(" fip: 0x%08x\n", 133 (((UInt)m_fpu_state.env[FP_ENV_IP+1]) << 16) | 134 ((UInt)m_fpu_state.env[FP_ENV_IP]) ); 135 printf(" fcs: 0x%04x\n", 136 ((UInt)m_fpu_state.env[FP_ENV_CS]) ); 137 printf(" fopoff: 0x%08x\n", 138 (((UInt)m_fpu_state.env[FP_ENV_OPOFF+1]) << 16) | 139 ((UInt)m_fpu_state.env[FP_ENV_OPOFF]) ); 140 printf(" fopsel: 0x%04x\n", 141 ((UInt)m_fpu_state.env[FP_ENV_OPSEL]) ); 142} 143 144 145/* ------------------------------------------------- */ 146 147 148/* Initialise the FPU, dump its state, and print it. */ 149 150 151void show ( unsigned char* st ) 152{ 153 int i; 154 for (i = 0; i < 28; i++) { 155 printf("%02x ", st[i]); 156 if (i > 0 && ((i & 3) == 3)) printf("\n"); 157 } 158 for (i = 0; i < 80; i++) { 159 printf("%02x ", st[i+28]); 160 if (i > 0 && ((i % 10) == 9)) printf("\n"); 161 } 162 printf("\n"); 163} 164 165int main ( void ) 166{ 167 Fpu_State* st = &m_fpu_state; 168 assert(sizeof(m_fpu_state) == 108); 169 asm volatile ("finit ; fnsave %0" 170 : "=m" (m_fpu_state) 171 : 172 : "memory" ); 173 printFpuState(); 174 printf("\n\n"); 175 176 asm volatile ("fildl 0(%%esp) ; pushl $17 ; fildl 0(%%esp) ; addl $4, %%esp ; fnsave %0" 177 : "=m" (m_fpu_state) 178 : 179 : "memory" ); 180 printFpuState(); 181 printf("\n"); 182 show(st); 183 return 0; 184} 185