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Diffstat (limited to 'nsprpub/pr/src/misc/prlong.c')
-rw-r--r--nsprpub/pr/src/misc/prlong.c355
1 files changed, 185 insertions, 170 deletions
diff --git a/nsprpub/pr/src/misc/prlong.c b/nsprpub/pr/src/misc/prlong.c
index 185fa5cd48..9c5abf06bb 100644
--- a/nsprpub/pr/src/misc/prlong.c
+++ b/nsprpub/pr/src/misc/prlong.c
@@ -10,10 +10,18 @@ static PRInt64 ll_maxint = PR_INT64(0x7fffffffffffffff);
static PRInt64 ll_minint = PR_INT64(0x8000000000000000);
static PRUint64 ll_maxuint = PR_UINT64(0xffffffffffffffff);
-PR_IMPLEMENT(PRInt64) LL_Zero(void) { return ll_zero; }
-PR_IMPLEMENT(PRInt64) LL_MaxInt(void) { return ll_maxint; }
-PR_IMPLEMENT(PRInt64) LL_MinInt(void) { return ll_minint; }
-PR_IMPLEMENT(PRUint64) LL_MaxUint(void) { return ll_maxuint; }
+PR_IMPLEMENT(PRInt64) LL_Zero(void) {
+ return ll_zero;
+}
+PR_IMPLEMENT(PRInt64) LL_MaxInt(void) {
+ return ll_maxint;
+}
+PR_IMPLEMENT(PRInt64) LL_MinInt(void) {
+ return ll_minint;
+}
+PR_IMPLEMENT(PRUint64) LL_MaxUint(void) {
+ return ll_maxuint;
+}
#ifndef HAVE_LONG_LONG
/*
@@ -32,10 +40,10 @@ static void norm_udivmod32(PRUint32 *qp, PRUint32 *rp, PRUint64 a, PRUint32 b)
r1 = (r1 << 16) | _hi16(a.lo);
if (r1 < m) {
q1--, r1 += b;
- if (r1 >= b /* i.e., we didn't get a carry when adding to r1 */
- && r1 < m) {
- q1--, r1 += b;
- }
+ if (r1 >= b /* i.e., we didn't get a carry when adding to r1 */
+ && r1 < m) {
+ q1--, r1 += b;
+ }
}
r1 -= m;
r0 = r1 % d1;
@@ -45,9 +53,9 @@ static void norm_udivmod32(PRUint32 *qp, PRUint32 *rp, PRUint64 a, PRUint32 b)
if (r0 < m) {
q0--, r0 += b;
if (r0 >= b
- && r0 < m) {
- q0--, r0 += b;
- }
+ && r0 < m) {
+ q0--, r0 += b;
+ }
}
*qp = (q1 << 16) | q0;
*rp = r0 - m;
@@ -58,18 +66,24 @@ static PRUint32 CountLeadingZeros(PRUint32 a)
PRUint32 t;
PRUint32 r = 32;
- if ((t = a >> 16) != 0)
- r -= 16, a = t;
- if ((t = a >> 8) != 0)
- r -= 8, a = t;
- if ((t = a >> 4) != 0)
- r -= 4, a = t;
- if ((t = a >> 2) != 0)
- r -= 2, a = t;
- if ((t = a >> 1) != 0)
- r -= 1, a = t;
- if (a & 1)
- r--;
+ if ((t = a >> 16) != 0) {
+ r -= 16, a = t;
+ }
+ if ((t = a >> 8) != 0) {
+ r -= 8, a = t;
+ }
+ if ((t = a >> 4) != 0) {
+ r -= 4, a = t;
+ }
+ if ((t = a >> 2) != 0) {
+ r -= 2, a = t;
+ }
+ if ((t = a >> 1) != 0) {
+ r -= 1, a = t;
+ }
+ if (a & 1) {
+ r--;
+ }
return r;
}
@@ -83,157 +97,158 @@ PR_IMPLEMENT(void) ll_udivmod(PRUint64 *qp, PRUint64 *rp, PRUint64 a, PRUint64 b
n1 = a.hi;
if (b.hi == 0) {
- if (b.lo > n1) {
- /* (0 q0) = (n1 n0) / (0 D0) */
-
- lsh = CountLeadingZeros(b.lo);
-
- if (lsh) {
- /*
- * Normalize, i.e. make the most significant bit of the
- * denominator be set.
- */
- b.lo = b.lo << lsh;
- n1 = (n1 << lsh) | (n0 >> (32 - lsh));
- n0 = n0 << lsh;
- }
-
- a.lo = n0, a.hi = n1;
- norm_udivmod32(&q0, &n0, a, b.lo);
- q1 = 0;
-
- /* remainder is in n0 >> lsh */
- } else {
- /* (q1 q0) = (n1 n0) / (0 d0) */
-
- if (b.lo == 0) /* user wants to divide by zero! */
- b.lo = 1 / b.lo; /* so go ahead and crash */
-
- lsh = CountLeadingZeros(b.lo);
-
- if (lsh == 0) {
- /*
- * From (n1 >= b.lo)
- * && (the most significant bit of b.lo is set),
- * conclude that
- * (the most significant bit of n1 is set)
- * && (the leading quotient digit q1 = 1).
- *
- * This special case is necessary, not an optimization
- * (Shifts counts of 32 are undefined).
- */
- n1 -= b.lo;
- q1 = 1;
- } else {
- /*
- * Normalize.
- */
- rsh = 32 - lsh;
-
- b.lo = b.lo << lsh;
- n2 = n1 >> rsh;
- n1 = (n1 << lsh) | (n0 >> rsh);
- n0 = n0 << lsh;
-
- a.lo = n1, a.hi = n2;
- norm_udivmod32(&q1, &n1, a, b.lo);
- }
-
- /* n1 != b.lo... */
-
- a.lo = n0, a.hi = n1;
- norm_udivmod32(&q0, &n0, a, b.lo);
-
- /* remainder in n0 >> lsh */
- }
-
- if (rp) {
- rp->lo = n0 >> lsh;
- rp->hi = 0;
- }
+ if (b.lo > n1) {
+ /* (0 q0) = (n1 n0) / (0 D0) */
+
+ lsh = CountLeadingZeros(b.lo);
+
+ if (lsh) {
+ /*
+ * Normalize, i.e. make the most significant bit of the
+ * denominator be set.
+ */
+ b.lo = b.lo << lsh;
+ n1 = (n1 << lsh) | (n0 >> (32 - lsh));
+ n0 = n0 << lsh;
+ }
+
+ a.lo = n0, a.hi = n1;
+ norm_udivmod32(&q0, &n0, a, b.lo);
+ q1 = 0;
+
+ /* remainder is in n0 >> lsh */
+ } else {
+ /* (q1 q0) = (n1 n0) / (0 d0) */
+
+ if (b.lo == 0) { /* user wants to divide by zero! */
+ b.lo = 1 / b.lo; /* so go ahead and crash */
+ }
+
+ lsh = CountLeadingZeros(b.lo);
+
+ if (lsh == 0) {
+ /*
+ * From (n1 >= b.lo)
+ * && (the most significant bit of b.lo is set),
+ * conclude that
+ * (the most significant bit of n1 is set)
+ * && (the leading quotient digit q1 = 1).
+ *
+ * This special case is necessary, not an optimization
+ * (Shifts counts of 32 are undefined).
+ */
+ n1 -= b.lo;
+ q1 = 1;
+ } else {
+ /*
+ * Normalize.
+ */
+ rsh = 32 - lsh;
+
+ b.lo = b.lo << lsh;
+ n2 = n1 >> rsh;
+ n1 = (n1 << lsh) | (n0 >> rsh);
+ n0 = n0 << lsh;
+
+ a.lo = n1, a.hi = n2;
+ norm_udivmod32(&q1, &n1, a, b.lo);
+ }
+
+ /* n1 != b.lo... */
+
+ a.lo = n0, a.hi = n1;
+ norm_udivmod32(&q0, &n0, a, b.lo);
+
+ /* remainder in n0 >> lsh */
+ }
+
+ if (rp) {
+ rp->lo = n0 >> lsh;
+ rp->hi = 0;
+ }
} else {
- if (b.hi > n1) {
- /* (0 0) = (n1 n0) / (D1 d0) */
-
- q0 = 0;
- q1 = 0;
-
- /* remainder in (n1 n0) */
- if (rp) {
- rp->lo = n0;
- rp->hi = n1;
- }
- } else {
- /* (0 q0) = (n1 n0) / (d1 d0) */
-
- lsh = CountLeadingZeros(b.hi);
- if (lsh == 0) {
- /*
- * From (n1 >= b.hi)
- * && (the most significant bit of b.hi is set),
- * conclude that
- * (the most significant bit of n1 is set)
- * && (the quotient digit q0 = 0 or 1).
- *
- * This special case is necessary, not an optimization.
- */
-
- /*
- * The condition on the next line takes advantage of that
- * n1 >= b.hi (true due to control flow).
- */
- if (n1 > b.hi || n0 >= b.lo) {
- q0 = 1;
- a.lo = n0, a.hi = n1;
- LL_SUB(a, a, b);
- } else {
- q0 = 0;
- }
- q1 = 0;
-
- if (rp) {
- rp->lo = n0;
- rp->hi = n1;
- }
- } else {
- PRInt64 m;
-
- /*
- * Normalize.
- */
- rsh = 32 - lsh;
-
- b.hi = (b.hi << lsh) | (b.lo >> rsh);
- b.lo = b.lo << lsh;
- n2 = n1 >> rsh;
- n1 = (n1 << lsh) | (n0 >> rsh);
- n0 = n0 << lsh;
-
- a.lo = n1, a.hi = n2;
- norm_udivmod32(&q0, &n1, a, b.hi);
- LL_MUL32(m, q0, b.lo);
-
- if ((m.hi > n1) || ((m.hi == n1) && (m.lo > n0))) {
- q0--;
- LL_SUB(m, m, b);
- }
-
- q1 = 0;
-
- /* Remainder is ((n1 n0) - (m1 m0)) >> lsh */
- if (rp) {
- a.lo = n0, a.hi = n1;
- LL_SUB(a, a, m);
- rp->lo = (a.hi << rsh) | (a.lo >> lsh);
- rp->hi = a.hi >> lsh;
- }
- }
- }
+ if (b.hi > n1) {
+ /* (0 0) = (n1 n0) / (D1 d0) */
+
+ q0 = 0;
+ q1 = 0;
+
+ /* remainder in (n1 n0) */
+ if (rp) {
+ rp->lo = n0;
+ rp->hi = n1;
+ }
+ } else {
+ /* (0 q0) = (n1 n0) / (d1 d0) */
+
+ lsh = CountLeadingZeros(b.hi);
+ if (lsh == 0) {
+ /*
+ * From (n1 >= b.hi)
+ * && (the most significant bit of b.hi is set),
+ * conclude that
+ * (the most significant bit of n1 is set)
+ * && (the quotient digit q0 = 0 or 1).
+ *
+ * This special case is necessary, not an optimization.
+ */
+
+ /*
+ * The condition on the next line takes advantage of that
+ * n1 >= b.hi (true due to control flow).
+ */
+ if (n1 > b.hi || n0 >= b.lo) {
+ q0 = 1;
+ a.lo = n0, a.hi = n1;
+ LL_SUB(a, a, b);
+ } else {
+ q0 = 0;
+ }
+ q1 = 0;
+
+ if (rp) {
+ rp->lo = n0;
+ rp->hi = n1;
+ }
+ } else {
+ PRInt64 m;
+
+ /*
+ * Normalize.
+ */
+ rsh = 32 - lsh;
+
+ b.hi = (b.hi << lsh) | (b.lo >> rsh);
+ b.lo = b.lo << lsh;
+ n2 = n1 >> rsh;
+ n1 = (n1 << lsh) | (n0 >> rsh);
+ n0 = n0 << lsh;
+
+ a.lo = n1, a.hi = n2;
+ norm_udivmod32(&q0, &n1, a, b.hi);
+ LL_MUL32(m, q0, b.lo);
+
+ if ((m.hi > n1) || ((m.hi == n1) && (m.lo > n0))) {
+ q0--;
+ LL_SUB(m, m, b);
+ }
+
+ q1 = 0;
+
+ /* Remainder is ((n1 n0) - (m1 m0)) >> lsh */
+ if (rp) {
+ a.lo = n0, a.hi = n1;
+ LL_SUB(a, a, m);
+ rp->lo = (a.hi << rsh) | (a.lo >> lsh);
+ rp->hi = a.hi >> lsh;
+ }
+ }
+ }
}
if (qp) {
- qp->lo = q0;
- qp->hi = q1;
+ qp->lo = q0;
+ qp->hi = q1;
}
}
#endif /* !HAVE_LONG_LONG */
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