sign. */
#define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
\f
+/* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
+ We do that by representing the two-word integer in 4 words, with only
+ HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
+ number. The value of the word is LOWPART + HIGHPART * BASE. */
+
+#define LOWPART(x) \
+ ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
+#define HIGHPART(x) \
+ ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
+#define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
+
+/* Unpack a two-word integer into 4 words.
+ LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
+ WORDS points to the array of HOST_WIDE_INTs. */
+
+static void
+encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
+{
+ words[0] = LOWPART (low);
+ words[1] = HIGHPART (low);
+ words[2] = LOWPART (hi);
+ words[3] = HIGHPART (hi);
+}
+
+/* Pack an array of 4 words into a two-word integer.
+ WORDS points to the array of words.
+ The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
+
+static void
+decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
+ HOST_WIDE_INT *hi)
+{
+ *low = words[0] + words[1] * BASE;
+ *hi = words[2] + words[3] * BASE;
+}
+\f
+/* Force the double-word integer L1, H1 to be within the range of the
+ integer type TYPE. Stores the properly truncated and sign-extended
+ double-word integer in *LV, *HV. Returns true if the operation
+ overflows, that is, argument and result are different. */
+
+int
+fit_double_type (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, const_tree type)
+{
+ unsigned HOST_WIDE_INT low0 = l1;
+ HOST_WIDE_INT high0 = h1;
+ unsigned int prec = TYPE_PRECISION (type);
+ int sign_extended_type;
+
+ /* Size types *are* sign extended. */
+ sign_extended_type = (!TYPE_UNSIGNED (type)
+ || (TREE_CODE (type) == INTEGER_TYPE
+ && TYPE_IS_SIZETYPE (type)));
+
+ /* First clear all bits that are beyond the type's precision. */
+ if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
+ ;
+ else if (prec > HOST_BITS_PER_WIDE_INT)
+ h1 &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
+ else
+ {
+ h1 = 0;
+ if (prec < HOST_BITS_PER_WIDE_INT)
+ l1 &= ~((HOST_WIDE_INT) (-1) << prec);
+ }
+
+ /* Then do sign extension if necessary. */
+ if (!sign_extended_type)
+ /* No sign extension */;
+ else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
+ /* Correct width already. */;
+ else if (prec > HOST_BITS_PER_WIDE_INT)
+ {
+ /* Sign extend top half? */
+ if (h1 & ((unsigned HOST_WIDE_INT)1
+ << (prec - HOST_BITS_PER_WIDE_INT - 1)))
+ h1 |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
+ }
+ else if (prec == HOST_BITS_PER_WIDE_INT)
+ {
+ if ((HOST_WIDE_INT)l1 < 0)
+ h1 = -1;
+ }
+ else
+ {
+ /* Sign extend bottom half? */
+ if (l1 & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
+ {
+ h1 = -1;
+ l1 |= (HOST_WIDE_INT)(-1) << prec;
+ }
+ }
+
+ *lv = l1;
+ *hv = h1;
+
+ /* If the value didn't fit, signal overflow. */
+ return l1 != low0 || h1 != high0;
+}
+
+/* We force the double-int HIGH:LOW to the range of the type TYPE by
+ sign or zero extending it.
+ OVERFLOWABLE indicates if we are interested
+ in overflow of the value, when >0 we are only interested in signed
+ overflow, for <0 we are interested in any overflow. OVERFLOWED
+ indicates whether overflow has already occurred. CONST_OVERFLOWED
+ indicates whether constant overflow has already occurred. We force
+ T's value to be within range of T's type (by setting to 0 or 1 all
+ the bits outside the type's range). We set TREE_OVERFLOWED if,
+ OVERFLOWED is nonzero,
+ or OVERFLOWABLE is >0 and signed overflow occurs
+ or OVERFLOWABLE is <0 and any overflow occurs
+ We return a new tree node for the extended double-int. The node
+ is shared if no overflow flags are set. */
+
+tree
+force_fit_type_double (tree type, unsigned HOST_WIDE_INT low,
+ HOST_WIDE_INT high, int overflowable,
+ bool overflowed)
+{
+ int sign_extended_type;
+ bool overflow;
+
+ /* Size types *are* sign extended. */
+ sign_extended_type = (!TYPE_UNSIGNED (type)
+ || (TREE_CODE (type) == INTEGER_TYPE
+ && TYPE_IS_SIZETYPE (type)));
+
+ overflow = fit_double_type (low, high, &low, &high, type);
+
+ /* If we need to set overflow flags, return a new unshared node. */
+ if (overflowed || overflow)
+ {
+ if (overflowed
+ || overflowable < 0
+ || (overflowable > 0 && sign_extended_type))
+ {
+ tree t = make_node (INTEGER_CST);
+ TREE_INT_CST_LOW (t) = low;
+ TREE_INT_CST_HIGH (t) = high;
+ TREE_TYPE (t) = type;
+ TREE_OVERFLOW (t) = 1;
+ return t;
+ }
+ }
+
+ /* Else build a shared node. */
+ return build_int_cst_wide (type, low, high);
+}
+\f
+/* Add two doubleword integers with doubleword result.
+ Return nonzero if the operation overflows according to UNSIGNED_P.
+ Each argument is given as two `HOST_WIDE_INT' pieces.
+ One argument is L1 and H1; the other, L2 and H2.
+ The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
+
+int
+add_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
+ bool unsigned_p)
+{
+ unsigned HOST_WIDE_INT l;
+ HOST_WIDE_INT h;
+
+ l = l1 + l2;
+ h = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) h1
+ + (unsigned HOST_WIDE_INT) h2
+ + (l < l1));
+
+ *lv = l;
+ *hv = h;
+
+ if (unsigned_p)
+ return ((unsigned HOST_WIDE_INT) h < (unsigned HOST_WIDE_INT) h1
+ || (h == h1
+ && l < l1));
+ else
+ return OVERFLOW_SUM_SIGN (h1, h2, h);
+}
+
+/* Negate a doubleword integer with doubleword result.
+ Return nonzero if the operation overflows, assuming it's signed.
+ The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
+ The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
+
+int
+neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
+{
+ if (l1 == 0)
+ {
+ *lv = 0;
+ *hv = - h1;
+ return (*hv & h1) < 0;
+ }
+ else
+ {
+ *lv = -l1;
+ *hv = ~h1;
+ return 0;
+ }
+}
+\f
+/* Multiply two doubleword integers with doubleword result.
+ Return nonzero if the operation overflows according to UNSIGNED_P.
+ Each argument is given as two `HOST_WIDE_INT' pieces.
+ One argument is L1 and H1; the other, L2 and H2.
+ The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
+
+int
+mul_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
+ bool unsigned_p)
+{
+ HOST_WIDE_INT arg1[4];
+ HOST_WIDE_INT arg2[4];
+ HOST_WIDE_INT prod[4 * 2];
+ unsigned HOST_WIDE_INT carry;
+ int i, j, k;
+ unsigned HOST_WIDE_INT toplow, neglow;
+ HOST_WIDE_INT tophigh, neghigh;
+
+ encode (arg1, l1, h1);
+ encode (arg2, l2, h2);
+
+ memset (prod, 0, sizeof prod);
+
+ for (i = 0; i < 4; i++)
+ {
+ carry = 0;
+ for (j = 0; j < 4; j++)
+ {
+ k = i + j;
+ /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
+ carry += arg1[i] * arg2[j];
+ /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
+ carry += prod[k];
+ prod[k] = LOWPART (carry);
+ carry = HIGHPART (carry);
+ }
+ prod[i + 4] = carry;
+ }
+
+ decode (prod, lv, hv);
+ decode (prod + 4, &toplow, &tophigh);
+
+ /* Unsigned overflow is immediate. */
+ if (unsigned_p)
+ return (toplow | tophigh) != 0;
+
+ /* Check for signed overflow by calculating the signed representation of the
+ top half of the result; it should agree with the low half's sign bit. */
+ if (h1 < 0)
+ {
+ neg_double (l2, h2, &neglow, &neghigh);
+ add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
+ }
+ if (h2 < 0)
+ {
+ neg_double (l1, h1, &neglow, &neghigh);
+ add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
+ }
+ return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
+}
+\f
+/* Shift the doubleword integer in L1, H1 left by COUNT places
+ keeping only PREC bits of result.
+ Shift right if COUNT is negative.
+ ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
+ Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
+
+void
+lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ HOST_WIDE_INT count, unsigned int prec,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, bool arith)
+{
+ unsigned HOST_WIDE_INT signmask;
+
+ if (count < 0)
+ {
+ rshift_double (l1, h1, -count, prec, lv, hv, arith);
+ return;
+ }
+
+ if (SHIFT_COUNT_TRUNCATED)
+ count %= prec;
+
+ if (count >= 2 * HOST_BITS_PER_WIDE_INT)
+ {
+ /* Shifting by the host word size is undefined according to the
+ ANSI standard, so we must handle this as a special case. */
+ *hv = 0;
+ *lv = 0;
+ }
+ else if (count >= HOST_BITS_PER_WIDE_INT)
+ {
+ *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
+ *lv = 0;
+ }
+ else
+ {
+ *hv = (((unsigned HOST_WIDE_INT) h1 << count)
+ | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
+ *lv = l1 << count;
+ }
+
+ /* Sign extend all bits that are beyond the precision. */
+
+ signmask = -((prec > HOST_BITS_PER_WIDE_INT
+ ? ((unsigned HOST_WIDE_INT) *hv
+ >> (prec - HOST_BITS_PER_WIDE_INT - 1))
+ : (*lv >> (prec - 1))) & 1);
+
+ if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
+ ;
+ else if (prec >= HOST_BITS_PER_WIDE_INT)
+ {
+ *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
+ *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
+ }
+ else
+ {
+ *hv = signmask;
+ *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
+ *lv |= signmask << prec;
+ }
+}
+
+/* Shift the doubleword integer in L1, H1 right by COUNT places
+ keeping only PREC bits of result. Shift left if COUNT is negative.
+ ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
+ Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
+
+void
+rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ HOST_WIDE_INT count, unsigned int prec,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
+ bool arith)
+{
+ unsigned HOST_WIDE_INT signmask;
+
+ signmask = (arith
+ ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
+ : 0);
+
+ if (SHIFT_COUNT_TRUNCATED)
+ count %= prec;
+
+ if (count >= 2 * HOST_BITS_PER_WIDE_INT)
+ {
+ /* Shifting by the host word size is undefined according to the
+ ANSI standard, so we must handle this as a special case. */
+ *hv = 0;
+ *lv = 0;
+ }
+ else if (count >= HOST_BITS_PER_WIDE_INT)
+ {
+ *hv = 0;
+ *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
+ }
+ else
+ {
+ *hv = (unsigned HOST_WIDE_INT) h1 >> count;
+ *lv = ((l1 >> count)
+ | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
+ }
+
+ /* Zero / sign extend all bits that are beyond the precision. */
+
+ if (count >= (HOST_WIDE_INT)prec)
+ {
+ *hv = signmask;
+ *lv = signmask;
+ }
+ else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
+ ;
+ else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
+ {
+ *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
+ *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
+ }
+ else
+ {
+ *hv = signmask;
+ *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
+ *lv |= signmask << (prec - count);
+ }
+}
+\f
+/* Rotate the doubleword integer in L1, H1 left by COUNT places
+ keeping only PREC bits of result.
+ Rotate right if COUNT is negative.
+ Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
+
+void
+lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ HOST_WIDE_INT count, unsigned int prec,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
+{
+ unsigned HOST_WIDE_INT s1l, s2l;
+ HOST_WIDE_INT s1h, s2h;
+
+ count %= prec;
+ if (count < 0)
+ count += prec;
+
+ lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
+ rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
+ *lv = s1l | s2l;
+ *hv = s1h | s2h;
+}
+
+/* Rotate the doubleword integer in L1, H1 left by COUNT places
+ keeping only PREC bits of result. COUNT must be positive.
+ Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
+
+void
+rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
+ HOST_WIDE_INT count, unsigned int prec,
+ unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
+{
+ unsigned HOST_WIDE_INT s1l, s2l;
+ HOST_WIDE_INT s1h, s2h;
+
+ count %= prec;
+ if (count < 0)
+ count += prec;
+
+ rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
+ lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
+ *lv = s1l | s2l;
+ *hv = s1h | s2h;
+}
+\f
+/* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
+ for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
+ CODE is a tree code for a kind of division, one of
+ TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
+ or EXACT_DIV_EXPR
+ It controls how the quotient is rounded to an integer.
+ Return nonzero if the operation overflows.
+ UNS nonzero says do unsigned division. */
+
+int
+div_and_round_double (enum tree_code code, int uns,
+ unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
+ HOST_WIDE_INT hnum_orig,
+ unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
+ HOST_WIDE_INT hden_orig,
+ unsigned HOST_WIDE_INT *lquo,
+ HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
+ HOST_WIDE_INT *hrem)
+{
+ int quo_neg = 0;
+ HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
+ HOST_WIDE_INT den[4], quo[4];
+ int i, j;
+ unsigned HOST_WIDE_INT work;
+ unsigned HOST_WIDE_INT carry = 0;
+ unsigned HOST_WIDE_INT lnum = lnum_orig;
+ HOST_WIDE_INT hnum = hnum_orig;
+ unsigned HOST_WIDE_INT lden = lden_orig;
+ HOST_WIDE_INT hden = hden_orig;
+ int overflow = 0;
+
+ if (hden == 0 && lden == 0)
+ overflow = 1, lden = 1;
+
+ /* Calculate quotient sign and convert operands to unsigned. */
+ if (!uns)
+ {
+ if (hnum < 0)
+ {
+ quo_neg = ~ quo_neg;
+ /* (minimum integer) / (-1) is the only overflow case. */
+ if (neg_double (lnum, hnum, &lnum, &hnum)
+ && ((HOST_WIDE_INT) lden & hden) == -1)
+ overflow = 1;
+ }
+ if (hden < 0)
+ {
+ quo_neg = ~ quo_neg;
+ neg_double (lden, hden, &lden, &hden);
+ }
+ }
+
+ if (hnum == 0 && hden == 0)
+ { /* single precision */
+ *hquo = *hrem = 0;
+ /* This unsigned division rounds toward zero. */
+ *lquo = lnum / lden;
+ goto finish_up;
+ }
+
+ if (hnum == 0)
+ { /* trivial case: dividend < divisor */
+ /* hden != 0 already checked. */
+ *hquo = *lquo = 0;
+ *hrem = hnum;
+ *lrem = lnum;
+ goto finish_up;
+ }
+
+ memset (quo, 0, sizeof quo);
+
+ memset (num, 0, sizeof num); /* to zero 9th element */
+ memset (den, 0, sizeof den);
+
+ encode (num, lnum, hnum);
+ encode (den, lden, hden);
+
+ /* Special code for when the divisor < BASE. */
+ if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
+ {
+ /* hnum != 0 already checked. */
+ for (i = 4 - 1; i >= 0; i--)
+ {
+ work = num[i] + carry * BASE;
+ quo[i] = work / lden;
+ carry = work % lden;
+ }
+ }
+ else
+ {
+ /* Full double precision division,
+ with thanks to Don Knuth's "Seminumerical Algorithms". */
+ int num_hi_sig, den_hi_sig;
+ unsigned HOST_WIDE_INT quo_est, scale;
+
+ /* Find the highest nonzero divisor digit. */
+ for (i = 4 - 1;; i--)
+ if (den[i] != 0)
+ {
+ den_hi_sig = i;
+ break;
+ }
+
+ /* Insure that the first digit of the divisor is at least BASE/2.
+ This is required by the quotient digit estimation algorithm. */
+
+ scale = BASE / (den[den_hi_sig] + 1);
+ if (scale > 1)
+ { /* scale divisor and dividend */
+ carry = 0;
+ for (i = 0; i <= 4 - 1; i++)
+ {
+ work = (num[i] * scale) + carry;
+ num[i] = LOWPART (work);
+ carry = HIGHPART (work);
+ }
+
+ num[4] = carry;
+ carry = 0;
+ for (i = 0; i <= 4 - 1; i++)
+ {
+ work = (den[i] * scale) + carry;
+ den[i] = LOWPART (work);
+ carry = HIGHPART (work);
+ if (den[i] != 0) den_hi_sig = i;
+ }
+ }
+
+ num_hi_sig = 4;
+
+ /* Main loop */
+ for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
+ {
+ /* Guess the next quotient digit, quo_est, by dividing the first
+ two remaining dividend digits by the high order quotient digit.
+ quo_est is never low and is at most 2 high. */
+ unsigned HOST_WIDE_INT tmp;
+
+ num_hi_sig = i + den_hi_sig + 1;
+ work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
+ if (num[num_hi_sig] != den[den_hi_sig])
+ quo_est = work / den[den_hi_sig];
+ else
+ quo_est = BASE - 1;
+
+ /* Refine quo_est so it's usually correct, and at most one high. */
+ tmp = work - quo_est * den[den_hi_sig];
+ if (tmp < BASE
+ && (den[den_hi_sig - 1] * quo_est
+ > (tmp * BASE + num[num_hi_sig - 2])))
+ quo_est--;
+
+ /* Try QUO_EST as the quotient digit, by multiplying the
+ divisor by QUO_EST and subtracting from the remaining dividend.
+ Keep in mind that QUO_EST is the I - 1st digit. */
+
+ carry = 0;
+ for (j = 0; j <= den_hi_sig; j++)
+ {
+ work = quo_est * den[j] + carry;
+ carry = HIGHPART (work);
+ work = num[i + j] - LOWPART (work);
+ num[i + j] = LOWPART (work);
+ carry += HIGHPART (work) != 0;
+ }
+
+ /* If quo_est was high by one, then num[i] went negative and
+ we need to correct things. */
+ if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
+ {
+ quo_est--;
+ carry = 0; /* add divisor back in */
+ for (j = 0; j <= den_hi_sig; j++)
+ {
+ work = num[i + j] + den[j] + carry;
+ carry = HIGHPART (work);
+ num[i + j] = LOWPART (work);
+ }
+
+ num [num_hi_sig] += carry;
+ }
+
+ /* Store the quotient digit. */
+ quo[i] = quo_est;
+ }
+ }
+
+ decode (quo, lquo, hquo);
+
+ finish_up:
+ /* If result is negative, make it so. */
+ if (quo_neg)
+ neg_double (*lquo, *hquo, lquo, hquo);
+
+ /* Compute trial remainder: rem = num - (quo * den) */
+ mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
+ neg_double (*lrem, *hrem, lrem, hrem);
+ add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
+
+ switch (code)
+ {
+ case TRUNC_DIV_EXPR:
+ case TRUNC_MOD_EXPR: /* round toward zero */
+ case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
+ return overflow;
+
+ case FLOOR_DIV_EXPR:
+ case FLOOR_MOD_EXPR: /* round toward negative infinity */
+ if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
+ {
+ /* quo = quo - 1; */
+ add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
+ lquo, hquo);
+ }
+ else
+ return overflow;
+ break;
+
+ case CEIL_DIV_EXPR:
+ case CEIL_MOD_EXPR: /* round toward positive infinity */
+ if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
+ {
+ add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
+ lquo, hquo);
+ }
+ else
+ return overflow;
+ break;
+
+ case ROUND_DIV_EXPR:
+ case ROUND_MOD_EXPR: /* round to closest integer */
+ {
+ unsigned HOST_WIDE_INT labs_rem = *lrem;
+ HOST_WIDE_INT habs_rem = *hrem;
+ unsigned HOST_WIDE_INT labs_den = lden, ltwice;
+ HOST_WIDE_INT habs_den = hden, htwice;
+
+ /* Get absolute values. */
+ if (*hrem < 0)
+ neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
+ if (hden < 0)
+ neg_double (lden, hden, &labs_den, &habs_den);
+
+ /* If (2 * abs (lrem) >= abs (lden)), adjust the quotient. */
+ mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
+ labs_rem, habs_rem, <wice, &htwice);
+
+ if (((unsigned HOST_WIDE_INT) habs_den
+ < (unsigned HOST_WIDE_INT) htwice)
+ || (((unsigned HOST_WIDE_INT) habs_den
+ == (unsigned HOST_WIDE_INT) htwice)
+ && (labs_den <= ltwice)))
+ {
+ if (*hquo < 0)
+ /* quo = quo - 1; */
+ add_double (*lquo, *hquo,
+ (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
+ else
+ /* quo = quo + 1; */
+ add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
+ lquo, hquo);
+ }
+ else
+ return overflow;
+ }
+ break;
+
+ default:
+ gcc_unreachable ();
+ }
+
+ /* Compute true remainder: rem = num - (quo * den) */
+ mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
+ neg_double (*lrem, *hrem, lrem, hrem);
+ add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
+ return overflow;
+}
+
/* If ARG2 divides ARG1 with zero remainder, carries out the division
of type CODE and returns the quotient.
Otherwise returns NULL_TREE. */
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