Bug Summary

File:subcmd/unitools/dword.c
Warning:line 228, column 2
Value stored to 'qB' is never read

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-unknown-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name dword.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fdebug-compilation-dir=/home/kfp/aldor/aldor/aldor/subcmd/unitools -fcoverage-compilation-dir=/home/kfp/aldor/aldor/aldor/subcmd/unitools -resource-dir /usr/local/lib/clang/18 -D PACKAGE_NAME="aldor" -D PACKAGE_TARNAME="aldor" -D PACKAGE_VERSION="1.4.0" -D PACKAGE_STRING="aldor 1.4.0" -D PACKAGE_BUGREPORT="aldor@xinutec.org" -D PACKAGE_URL="" -D PACKAGE="aldor" -D VERSION="1.4.0" -D YYTEXT_POINTER=1 -D HAVE_STDIO_H=1 -D HAVE_STDLIB_H=1 -D HAVE_STRING_H=1 -D HAVE_INTTYPES_H=1 -D HAVE_STDINT_H=1 -D HAVE_STRINGS_H=1 -D HAVE_SYS_STAT_H=1 -D HAVE_SYS_TYPES_H=1 -D HAVE_UNISTD_H=1 -D STDC_HEADERS=1 -D HAVE_LIBREADLINE=1 -D HAVE_READLINE_READLINE_H=1 -D HAVE_READLINE_HISTORY=1 -D HAVE_READLINE_HISTORY_H=1 -D USE_GLOOP_SHELL=1 -D GENERATOR_COROUTINES=0 -D HAVE_DLFCN_H=1 -D LT_OBJDIR=".libs/" -I . -I ./../../src -I ../../src -internal-isystem /usr/local/lib/clang/18/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/14/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -ferror-limit 19 -fgnuc-version=4.2.1 -fskip-odr-check-in-gmf -vectorize-loops -vectorize-slp -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2026-01-15-223856-845667-1 -x c dword.c
1/******************************************************************************
2 *
3 * :: Double Word operations.
4 *
5 *****************************************************************************/
6
7/* #ifdef FOAM_RTS */
8#include "axlgen.h"
9#include "bigint.h"
10#include "optcfg.h"
11typedef ULong BIntD; /* To contain two BInt digits. */
12
13#define BINT_LG_RADIX((8 * sizeof(BIntS))) (bitsizeof(BIntS)(8 * sizeof(BIntS)))
14#define BINT_RADIX(((unsigned long) 1) << ((8 * sizeof(BIntS)))) (((unsigned long) 1) << BINT_LG_RADIX((8 * sizeof(BIntS))))
15
16#define DivideDouble(q, r, nh, nl, d){ BIntD n_ = (BIntD)(nh)*(BIntD)(((unsigned long) 1) <<
((8 * sizeof(BIntS)))) + (nl); BIntD d_ = (d); (q) = n_ / d_
; (r) = n_ % d_; } { \
17 BIntD n_ = (BIntD)(nh)*(BIntD)BINT_RADIX(((unsigned long) 1) << ((8 * sizeof(BIntS)))) + (nl);\
18 BIntD d_ = (d); \
19 (q) = n_ / d_; \
20 (r) = n_ % d_; \
21}
22
23#ifdef BIGINT_TEST_BASE
24# define BASE_BITS(8 * sizeof(unsigned long)) 6
25# define __TEST_BASE (1L << BASE_BITS(8 * sizeof(unsigned long)))
26# define BASE_MINUS_1(9223372036854775807L *2UL+1UL) (__TEST_BASE - 1)
27# define MODB(x)(x) ((x) % __TEST_BASE)
28#else
29# define BASE_MINUS_1(9223372036854775807L *2UL+1UL) ULONG_MAX(9223372036854775807L *2UL+1UL)
30# define BASE_BITS(8 * sizeof(unsigned long)) (CHAR_BIT8 * sizeof(unsigned long))
31# define MODB(x)(x) (x)
32#endif
33
34#define BASE_BITS_2((8 * sizeof(unsigned long))/2) (BASE_BITS(8 * sizeof(unsigned long))/2)
35#define BASE_ROOT(1L << (((8 * sizeof(unsigned long))/2))) (1L << (BASE_BITS_2((8 * sizeof(unsigned long))/2)))
36#define COMPL(x)((9223372036854775807L *2UL+1UL) - (x)) (BASE_MINUS_1(9223372036854775807L *2UL+1UL) - (x))
37#define LO_HALF_LO(x)((x) & ((1L << (((8 * sizeof(unsigned long))/2)))-1
)) ((x) & (BASE_ROOT(1L << (((8 * sizeof(unsigned long))/2)))-1))
38#define HI_HALF_LO(x)((x) >> ((8 * sizeof(unsigned long))/2)) ((x) >> BASE_BITS_2((8 * sizeof(unsigned long))/2))
39#define LO_HALF_HI(x)(((x) & ((1L << (((8 * sizeof(unsigned long))/2)))-
1)) << ((8 * sizeof(unsigned long))/2)) (((x) & (BASE_ROOT(1L << (((8 * sizeof(unsigned long))/2)))-1)) << BASE_BITS_2((8 * sizeof(unsigned long))/2))
40#define HI_HALF_HI(x)(((x) >> (8 * sizeof(unsigned long))) << ((8 * sizeof
(unsigned long))/2)) (((x) >> BASE_BITS(8 * sizeof(unsigned long))) << BASE_BITS_2((8 * sizeof(unsigned long))/2))
41#define COMBINE(h, l)(((h) << ((8 * sizeof(unsigned long))/2)) | (l)) (((h) << BASE_BITS_2((8 * sizeof(unsigned long))/2)) | (l))
42#define HI_BIT(n)(((n) >> ((8 * sizeof(unsigned long))-1)) & 1) (((n) >> (BASE_BITS(8 * sizeof(unsigned long))-1)) & 1)
43
44
45void
46xxTestGtDouble(int *pb, ULong AH, ULong AL, ULong BH, ULong BL)
47{
48 *pb = AH > BH || (AH == BH && AL > BL);
49}
50
51#ifndef OPT_NoDoubleOps
52
53void
54xxTimesDouble(ULong *pH, ULong *pL, ULong A, ULong B)
55{
56 ULong Ah, Al, Bh, Bl;
57 ULong H, M, N, L;
58 ULong Mh, Mx, Nh, Nx;
59 ULong T;
60
61 Ah = HI_HALF_LO(A)((A) >> ((8 * sizeof(unsigned long))/2));
62 Al = LO_HALF_LO(A)((A) & ((1L << (((8 * sizeof(unsigned long))/2)))-1
));
63 Bh = HI_HALF_LO(B)((B) >> ((8 * sizeof(unsigned long))/2));
64 Bl = LO_HALF_LO(B)((B) & ((1L << (((8 * sizeof(unsigned long))/2)))-1
));
65
66 H = MODB(Ah * Bh)(Ah * Bh);
67 M = MODB(Al * Bh)(Al * Bh);
68 N = MODB(Ah * Bl)(Ah * Bl);
69 L = MODB(Al * Bl)(Al * Bl);
70
71 Mh = HI_HALF_LO(M)((M) >> ((8 * sizeof(unsigned long))/2));
72 Mx = LO_HALF_HI(M)(((M) & ((1L << (((8 * sizeof(unsigned long))/2)))-
1)) << ((8 * sizeof(unsigned long))/2));
73 Nh = HI_HALF_LO(N)((N) >> ((8 * sizeof(unsigned long))/2));
74 Nx = LO_HALF_HI(N)(((N) & ((1L << (((8 * sizeof(unsigned long))/2)))-
1)) << ((8 * sizeof(unsigned long))/2));
75
76 T = L;
77 L = MODB(L + Mx)(L + Mx);
78 H = MODB(H + (L < T))(H + (L < T));
79 H = MODB(H + Mh)(H + Mh);
80
81 T = L;
82 L = MODB(L + Nx)(L + Nx);
83 H = MODB(H + (L < T))(H + (L < T));
84 H = MODB(H + Nh)(H + Nh);
85
86 *pH= H;
87 *pL= L;
88}
89#endif
90
91void
92xxPlusStep(ULong *pko, ULong *pr, ULong a, ULong b, ULong ki)
93{
94 ULong ko, r;
95
96 r = MODB(a + b)(a + b);
97 ko = r < a;
98 r = MODB(r + ki)(r + ki);
99 ko+= r < ki;
100
101 *pko = ko;
102 *pr = r;
103}
104
105#define minusStep(pkp1out,pr,a,b,kp1in)plusStep(pkp1out,pr,a,((9223372036854775807L *2UL+1UL) - (b))
,kp1in) plusStep(pkp1out,pr,a,COMPL(b)((9223372036854775807L *2UL+1UL) - (b)),kp1in)
106
107void
108xxTimesStep(ULong *pko, ULong *pr, ULong a, ULong b, ULong c, ULong ki)
109{
110 ULong h, l, k, r;
111
112 xxTimesDouble(&h, &l, a, b);
113
114 r = MODB(l + c)(l + c);
115 k = r < l;
116 r = MODB(r + ki)(r + ki);
117 k += r < ki;
118 *pr = r;
119 r = MODB(h + k)(h + k);
120 *pko = r;
121}
122
123#ifndef OPT_NoDoubleOps
124
125void
126xxDivideDouble(ULong *pqh, ULong *pql, ULong *pr,
127 ULong nh, ULong nl, ULong d)
128{
129 ULong qh, ql, rh, rl; /* results */
130 ULong qrh,rrh,qrl,rrl,qB,rB; /* quo/rem rh, rl, base */
131 ULong Bd;
132 ULong th, tl; /* temporaries */
133
134
135 if (d == 1) {
136 *pqh = nh; *pql = nl;
137 *pr = 0;
138 return;
139 }
140 if (d < BASE_ROOT(1L << (((8 * sizeof(unsigned long))/2)))) {
141 ULong r = 0, th,tl;
142 DivideDouble(th, r, r, HI_HALF_LO(nh), d){ BIntD n_ = (BIntD)(r)*(BIntD)(((unsigned long) 1) << (
(8 * sizeof(BIntS)))) + (((nh) >> ((8 * sizeof(unsigned
long))/2))); BIntD d_ = (d); (th) = n_ / d_; (r) = n_ % d_; };
143 DivideDouble(tl, r, r, LO_HALF_LO(nh), d){ BIntD n_ = (BIntD)(r)*(BIntD)(((unsigned long) 1) << (
(8 * sizeof(BIntS)))) + (((nh) & ((1L << (((8 * sizeof
(unsigned long))/2)))-1))); BIntD d_ = (d); (tl) = n_ / d_; (
r) = n_ % d_; };
144 ql = COMBINE(th, tl)(((th) << ((8 * sizeof(unsigned long))/2)) | (tl));
145 DivideDouble(th, r, r, HI_HALF_LO(nl), d){ BIntD n_ = (BIntD)(r)*(BIntD)(((unsigned long) 1) << (
(8 * sizeof(BIntS)))) + (((nl) >> ((8 * sizeof(unsigned
long))/2))); BIntD d_ = (d); (th) = n_ / d_; (r) = n_ % d_; };
146 DivideDouble(tl, r, r, LO_HALF_LO(nl), d){ BIntD n_ = (BIntD)(r)*(BIntD)(((unsigned long) 1) << (
(8 * sizeof(BIntS)))) + (((nl) & ((1L << (((8 * sizeof
(unsigned long))/2)))-1))); BIntD d_ = (d); (tl) = n_ / d_; (
r) = n_ % d_; };
147 ql = COMBINE(th, tl)(((th) << ((8 * sizeof(unsigned long))/2)) | (tl));
148
149 *pqh = 0;
150 *pql = ql;
151 *pr = r;
152 return;
153 }
154 /*
155 * B-d = (B-1) - d + 1 = q' d + r' => B = (q' + 1) d + r'
156 */
157 Bd = COMPL(d-1)((9223372036854775807L *2UL+1UL) - (d-1));
158 qB = Bd / d + 1;
159 rB = Bd % d;
160
161 qh = 0; ql = 0;
162 rh = nh; rl = nl;
163
164 while (rh != 0 || rl >= d) {
165
166 qrh = rh / d; rrh = rh % d;
167 qrl = rl / d; rrl = rl % d;
168
169 /* [qh,ql] += qrh*B + rrh*qB + qrl */
170 /* [rh,rl] = rrh*rB + rrl */
171
172 /*
173 * xxTimesDouble(&h, &l, rrh, qB);
174 * plusStep (&k, &tl, l, qrl, 0);
175 * plusStep (&k, &th, h, k, 0);
176 * plusStep (&k, &ql, tl, ql, 0);
177 * plusStep (&k, &qh, th, qh, qrh+k);
178 */
179 xxTimesDouble(&th, &tl, rrh, qB);
180 tl = MODB(tl + qrl)(tl + qrl);
181 th = MODB(th + (tl < qrl))(th + (tl < qrl));
182 ql = MODB(ql + tl)(ql + tl);
183 qh = MODB(qh + (ql < tl))(qh + (ql < tl));
184 qh = MODB(qh + th)(qh + th);
185 qh = MODB(qh + qrh)(qh + qrh);
186
187 /*
188 * xxTimesStep(&rh, &rl, rrh, rB, rrl, 0);
189 */
190 xxTimesDouble(&th, &tl, rrh, rB);
191 rl = MODB(tl + rrl)(tl + rrl);
192 rh = MODB(th + (rl < rrl))(th + (rl < rrl));
193 }
194
195 *pqh = qh; *pql = ql;
196 *pr = rl;
197
198}
199
200
201/* As above, but no quotient */
202ULong
203xxModDouble(ULong nh, ULong nl, ULong d)
204{
205 ULong qh, ql, rh, rl; /* results */
206 ULong rrh,rrl,qB,rB; /* quo/rem rh, rl, base */
207 ULong Bd;
208 ULong th, tl; /* temporaries */
209
210 if (d == 1) {
211 return 0;
212 }
213
214 if (d < BASE_ROOT(1L << (((8 * sizeof(unsigned long))/2)))) {
215 ULong r = 0, tmp;
216 DivideDouble(tmp, r, r, HI_HALF_LO(nh), d){ BIntD n_ = (BIntD)(r)*(BIntD)(((unsigned long) 1) << (
(8 * sizeof(BIntS)))) + (((nh) >> ((8 * sizeof(unsigned
long))/2))); BIntD d_ = (d); (tmp) = n_ / d_; (r) = n_ % d_;
};
217 DivideDouble(tmp, r, r, LO_HALF_LO(nh), d){ BIntD n_ = (BIntD)(r)*(BIntD)(((unsigned long) 1) << (
(8 * sizeof(BIntS)))) + (((nh) & ((1L << (((8 * sizeof
(unsigned long))/2)))-1))); BIntD d_ = (d); (tmp) = n_ / d_; (
r) = n_ % d_; };
218 DivideDouble(tmp, r, r, HI_HALF_LO(nl), d){ BIntD n_ = (BIntD)(r)*(BIntD)(((unsigned long) 1) << (
(8 * sizeof(BIntS)))) + (((nl) >> ((8 * sizeof(unsigned
long))/2))); BIntD d_ = (d); (tmp) = n_ / d_; (r) = n_ % d_;
};
219 DivideDouble(tmp, r, r, LO_HALF_LO(nl), d){ BIntD n_ = (BIntD)(r)*(BIntD)(((unsigned long) 1) << (
(8 * sizeof(BIntS)))) + (((nl) & ((1L << (((8 * sizeof
(unsigned long))/2)))-1))); BIntD d_ = (d); (tmp) = n_ / d_; (
r) = n_ % d_; };
220
221 return r;
222 }
223
224 /*
225 * B-d = (B-1) - d + 1 = q' d + r' => B = (q' + 1) d + r'
226 */
227 Bd = COMPL(d-1)((9223372036854775807L *2UL+1UL) - (d-1));
228 qB = Bd / d + 1;
Value stored to 'qB' is never read
229 rB = Bd % d;
230
231 qh = 0; ql = 0;
232 rh = nh; rl = nl;
233
234 while (rh != 0 || rl >= d) {
235
236 rrh = rh % d;
237 rrl = rl % d;
238
239 /*
240 * xxTimesStep(&rh, &rl, rrh, rB, rrl, 0);
241 */
242 xxTimesDouble(&th, &tl, rrh, rB);
243 rl = MODB(tl + rrl)(tl + rrl);
244 rh = MODB(th + (rl < rrl))(th + (rl < rrl));
245 }
246
247 return rl;
248}
249
250#endif
251
252#if defined(BIGINT_TEST_BASE)
253
254#define BASE __TEST_BASE
255main()
256{
257 BIntS a, b, c, d, h, l, k;
258 BIntS r1, r2;
259 int t;
260
261 for (a = 0; a < BASE; a++) {
262 for (b = 0; b < BASE; b++) {
263 printf(".");
264
265 timesDouble(&h, &l, a, b);
266 r1 = h * BASE + l;
267 r2 = a * b;
268 if (h >= BASE || l >= BASE || r1 != r2)
269 printf("%d * %d fails\n", a, b);
270
271 plusStep(&h, &l, a, b, int0((int) 0));
272 r1 = h * BASE + l;
273 r2 = a + b + 0;
274 if (h >= BASE || l >= BASE || r1 != r2)
275 printf("%d + %d + 0 fails\n", a, b);
276
277 plusStep(&h, &l, a, b, 1);
278 r1 = h * BASE + l;
279 r2 = a + b + 1;
280 if (h >= BASE || l >= BASE || r1 != r2)
281 printf("%d + %d + 1 fails\n", a, b);
282
283 minusStep(&h, &l, a, b, 1)plusStep(&h,&l,a,((9223372036854775807L *2UL+1UL) - (
b)),1);
284 r1 = (h-1) * BASE + l;
285 r2 = a - b - 0;
286 if (h >= BASE || l >= BASE || r1 != r2)
287 printf("%d - %d - 0 fails\n", a, b);
288
289 minusStep(&h, &l, a, b, int0)plusStep(&h,&l,a,((9223372036854775807L *2UL+1UL) - (
b)),((int) 0));
290 r1 = (h-1) * BASE + l;
291 r2 = a - b - 1;
292 if (h >= BASE || l >= BASE || r1 != r2)
293 printf("%d - %d - 1 fails\n", a, b);
294
295 for (c = 0; c < BASE; c++) {
296 for (d = 0; d < BASE; d++) {
297
298 timesStep(&h, &l, a, b, c, d);
299 r1 = h * BASE + l;
300 r2 = a * b + c + d;
301 if (h >= BASE || l >= BASE || r1 != r2)
302 printf("%d * %d + %d + %d fails\n", a, b, c, d);
303
304 testGtDouble(&t, a, b, c, d);
305 r1 = t;
306 r2 = (a * BASE + b) > (c * BASE + d);
307 if (r1 != r2)
308 printf("%d,%d > %d,%d fails\n", a, b, c, d);
309 }
310 }
311 for (c = 1; c < BASE; c++) {
312 divideDouble(&h, &l, &k, a, b, c);
313
314 r1 = h * BASE + l;
315 r2 =(a * BASE + b) / c;
316 if (h >= BASE || l >= BASE || r1 != r2) {
317 printf("(%d,%d) / %d fails\n", a, b, c);
318 divideDouble(&h, &l, &k, a, b, c);
319 }
320
321 r1 = k;
322 r2 =(a * BASE + b) % c;
323 if (k >= BASE || r1 != r2) {
324 printf("(%d,%d) %% %d fails\n", a, b, c);
325 divideDouble(&h, &l, &k, a, b, c);
326 }
327 }
328
329 }
330 printf("\n");
331 }
332}
333
334#endif /* (BIGINT_TEST_WHOLE_WORDS) */