1 /* This has so very few changes over libgcc2's __udivmoddi4 it isn't funny. */ 2 3 #include <math-emu/soft-fp.h> 4 5 #undef count_leading_zeros 6 #define count_leading_zeros __FP_CLZ 7 8 void 9 _fp_udivmodti4(_FP_W_TYPE q[2], _FP_W_TYPE r[2], 10 _FP_W_TYPE n1, _FP_W_TYPE n0, 11 _FP_W_TYPE d1, _FP_W_TYPE d0) 12 { 13 _FP_W_TYPE q0, q1, r0, r1; 14 _FP_I_TYPE b, bm; 15 16 if (d1 == 0) 17 { 18 #if !UDIV_NEEDS_NORMALIZATION 19 if (d0 > n1) 20 { 21 /* 0q = nn / 0D */ 22 23 udiv_qrnnd (q0, n0, n1, n0, d0); 24 q1 = 0; 25 26 /* Remainder in n0. */ 27 } 28 else 29 { 30 /* qq = NN / 0d */ 31 32 if (d0 == 0) 33 d0 = 1 / d0; /* Divide intentionally by zero. */ 34 35 udiv_qrnnd (q1, n1, 0, n1, d0); 36 udiv_qrnnd (q0, n0, n1, n0, d0); 37 38 /* Remainder in n0. */ 39 } 40 41 r0 = n0; 42 r1 = 0; 43 44 #else /* UDIV_NEEDS_NORMALIZATION */ 45 46 if (d0 > n1) 47 { 48 /* 0q = nn / 0D */ 49 50 count_leading_zeros (bm, d0); 51 52 if (bm != 0) 53 { 54 /* Normalize, i.e. make the most significant bit of the 55 denominator set. */ 56 57 d0 = d0 << bm; 58 n1 = (n1 << bm) | (n0 >> (_FP_W_TYPE_SIZE - bm)); 59 n0 = n0 << bm; 60 } 61 62 udiv_qrnnd (q0, n0, n1, n0, d0); 63 q1 = 0; 64 65 /* Remainder in n0 >> bm. */ 66 } 67 else 68 { 69 /* qq = NN / 0d */ 70 71 if (d0 == 0) 72 d0 = 1 / d0; /* Divide intentionally by zero. */ 73 74 count_leading_zeros (bm, d0); 75 76 if (bm == 0) 77 { 78 /* From (n1 >= d0) /\ (the most significant bit of d0 is set), 79 conclude (the most significant bit of n1 is set) /\ (the 80 leading quotient digit q1 = 1). 81 82 This special case is necessary, not an optimization. 83 (Shifts counts of SI_TYPE_SIZE are undefined.) */ 84 85 n1 -= d0; 86 q1 = 1; 87 } 88 else 89 { 90 _FP_W_TYPE n2; 91 92 /* Normalize. */ 93 94 b = _FP_W_TYPE_SIZE - bm; 95 96 d0 = d0 << bm; 97 n2 = n1 >> b; 98 n1 = (n1 << bm) | (n0 >> b); 99 n0 = n0 << bm; 100 101 udiv_qrnnd (q1, n1, n2, n1, d0); 102 } 103 104 /* n1 != d0... */ 105 106 udiv_qrnnd (q0, n0, n1, n0, d0); 107 108 /* Remainder in n0 >> bm. */ 109 } 110 111 r0 = n0 >> bm; 112 r1 = 0; 113 #endif /* UDIV_NEEDS_NORMALIZATION */ 114 } 115 else 116 { 117 if (d1 > n1) 118 { 119 /* 00 = nn / DD */ 120 121 q0 = 0; 122 q1 = 0; 123 124 /* Remainder in n1n0. */ 125 r0 = n0; 126 r1 = n1; 127 } 128 else 129 { 130 /* 0q = NN / dd */ 131 132 count_leading_zeros (bm, d1); 133 if (bm == 0) 134 { 135 /* From (n1 >= d1) /\ (the most significant bit of d1 is set), 136 conclude (the most significant bit of n1 is set) /\ (the 137 quotient digit q0 = 0 or 1). 138 139 This special case is necessary, not an optimization. */ 140 141 /* The condition on the next line takes advantage of that 142 n1 >= d1 (true due to program flow). */ 143 if (n1 > d1 || n0 >= d0) 144 { 145 q0 = 1; 146 sub_ddmmss (n1, n0, n1, n0, d1, d0); 147 } 148 else 149 q0 = 0; 150 151 q1 = 0; 152 153 r0 = n0; 154 r1 = n1; 155 } 156 else 157 { 158 _FP_W_TYPE m1, m0, n2; 159 160 /* Normalize. */ 161 162 b = _FP_W_TYPE_SIZE - bm; 163 164 d1 = (d1 << bm) | (d0 >> b); 165 d0 = d0 << bm; 166 n2 = n1 >> b; 167 n1 = (n1 << bm) | (n0 >> b); 168 n0 = n0 << bm; 169 170 udiv_qrnnd (q0, n1, n2, n1, d1); 171 umul_ppmm (m1, m0, q0, d0); 172 173 if (m1 > n1 || (m1 == n1 && m0 > n0)) 174 { 175 q0--; 176 sub_ddmmss (m1, m0, m1, m0, d1, d0); 177 } 178 179 q1 = 0; 180 181 /* Remainder in (n1n0 - m1m0) >> bm. */ 182 sub_ddmmss (n1, n0, n1, n0, m1, m0); 183 r0 = (n1 << b) | (n0 >> bm); 184 r1 = n1 >> bm; 185 } 186 } 187 } 188 189 q[0] = q0; q[1] = q1; 190 r[0] = r0, r[1] = r1; 191 } 192