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fold-const.c (LOWPART, [...]): Move ... 

2010-04-15  Richard Guenther  <rguenther@suse.de>

	* fold-const.c (LOWPART, HIGHPART, BASE, encode, decode,
	fit_double_type, force_fit_type_double, add_double_with_sign,
	neg_double, mul_double_with_sign, lshift_double, rshift_double,
	lrotate_double, rrotate_double, div_and_round_double): Move ...
	* double-int.c: ... here.
	* tree.h (force_fit_type_double, fit_double_type, add_double_with_sign,
	add_double, neg_double, mul_double_with_sign, mul_double,
	lshift_double, rshift_double, lrotate_double, rrotate_double,
	div_and_round_double): Move prototypes ...
	* double-int.h: ... here.

From-SVN: r158372
This commit is contained in:
Richard Guenther 2010-04-15 12:45:58 +00:00 committed by Richard Biener
parent 0b3467c4a3
commit 330db1e301
5 changed files with 793 additions and 761 deletions
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13
gcc/ChangeLog
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@ -1,3 +1,16 @@
2010-04-15 Richard Guenther <rguenther@suse.de>
* fold-const.c (LOWPART, HIGHPART, BASE, encode, decode,
fit_double_type, force_fit_type_double, add_double_with_sign,
neg_double, mul_double_with_sign, lshift_double, rshift_double,
lrotate_double, rrotate_double, div_and_round_double): Move ...
* double-int.c: ... here.
* tree.h (force_fit_type_double, fit_double_type, add_double_with_sign,
add_double, neg_double, mul_double_with_sign, mul_double,
lshift_double, rshift_double, lrotate_double, rrotate_double,
div_and_round_double): Move prototypes ...
* double-int.h: ... here.
2010-04-15 Bernd Schmidt <bernd.schmidt@codesourcery.com>
PR target/43742

737
gcc/double-int.c
View File

@ -23,6 +23,741 @@ along with GCC; see the file COPYING3. If not see
#include "tm.h"
#include "tree.h"
/* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
and SUM1. Then this yields nonzero if overflow occurred during the
addition.
Overflow occurs if A and B have the same sign, but A and SUM differ in
sign. Use `^' to test whether signs differ, and `< 0' to isolate the
sign. */
#define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
/* 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;
}
/* 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);
}
/* 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;
}
}
/* 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;
}
/* 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;
if (count < 0)
{
lshift_double (l1, h1, -count, prec, lv, hv, arith);
return;
}
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);
}
}
/* 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;
}
/* 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 (unsigned code, int uns,
/* num == numerator == dividend */
unsigned HOST_WIDE_INT lnum_orig,
HOST_WIDE_INT hnum_orig,
/* den == denominator == divisor */
unsigned HOST_WIDE_INT lden_orig,
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, &ltwice, &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;
}
/* Returns mask for PREC bits. */
double_int
@ -211,7 +946,7 @@ double_int_divmod (double_int a, double_int b, bool uns, unsigned code,
{
double_int ret;
div_and_round_double ((enum tree_code) code, uns, a.low, a.high,
div_and_round_double (code, uns, a.low, a.high,
b.low, b.high, &ret.low, &ret.high,
&mod->low, &mod->high);
return ret;

49
gcc/double-int.h
View File

@ -59,13 +59,11 @@ typedef struct
#define HOST_BITS_PER_DOUBLE_INT (2 * HOST_BITS_PER_WIDE_INT)
union tree_node;
/* Constructors and conversions. */
union tree_node *double_int_to_tree (union tree_node *, double_int);
bool double_int_fits_to_tree_p (const union tree_node *, double_int);
double_int tree_to_double_int (const union tree_node *);
tree double_int_to_tree (tree, double_int);
bool double_int_fits_to_tree_p (const_tree, double_int);
double_int tree_to_double_int (const_tree);
/* Constructs double_int from integer CST. The bits over the precision of
HOST_WIDE_INT are filled with the sign bit. */
@ -202,6 +200,47 @@ double_int_equal_p (double_int cst1, double_int cst2)
return cst1.low == cst2.low && cst1.high == cst2.high;
}
/* Legacy interface with decomposed high/low parts. */
extern tree force_fit_type_double (tree, unsigned HOST_WIDE_INT, HOST_WIDE_INT,
int, bool);
extern int fit_double_type (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
const_tree);
extern int add_double_with_sign (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
unsigned HOST_WIDE_INT, HOST_WIDE_INT,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
bool);
#define add_double(l1,h1,l2,h2,lv,hv) \
add_double_with_sign (l1, h1, l2, h2, lv, hv, false)
extern int neg_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
extern int mul_double_with_sign (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
unsigned HOST_WIDE_INT, HOST_WIDE_INT,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
bool);
#define mul_double(l1,h1,l2,h2,lv,hv) \
mul_double_with_sign (l1, h1, l2, h2, lv, hv, false)
extern void lshift_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
HOST_WIDE_INT, unsigned int,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *, bool);
extern void rshift_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
HOST_WIDE_INT, unsigned int,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *, bool);
extern void lrotate_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
HOST_WIDE_INT, unsigned int,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
extern void rrotate_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
HOST_WIDE_INT, unsigned int,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
extern int div_and_round_double (unsigned, int, unsigned HOST_WIDE_INT,
HOST_WIDE_INT, unsigned HOST_WIDE_INT,
HOST_WIDE_INT, unsigned HOST_WIDE_INT *,
HOST_WIDE_INT *, unsigned HOST_WIDE_INT *,
HOST_WIDE_INT *);
#ifndef GENERATOR_FILE
/* Conversion to and from GMP integer representations. */

717
gcc/fold-const.c
View File

@ -93,8 +93,6 @@ enum comparison_code {
COMPCODE_TRUE = 15
};
static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
static bool negate_mathfn_p (enum built_in_function);
static bool negate_expr_p (tree);
static tree negate_expr (tree);
@ -159,721 +157,6 @@ static tree fold_convert_const (enum tree_code, tree, tree);
sign. */
#define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
/* 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;
}
/* 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);
}
/* 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;
}
}
/* 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;
}
/* 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);
}
}
/* 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;
}
/* 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, &ltwice, &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. */

38
gcc/tree.h
View File

@ -4820,44 +4820,6 @@ extern void fold_undefer_overflow_warnings (bool, const_gimple, int);
extern void fold_undefer_and_ignore_overflow_warnings (void);
extern bool fold_deferring_overflow_warnings_p (void);
extern tree force_fit_type_double (tree, unsigned HOST_WIDE_INT, HOST_WIDE_INT,
int, bool);
extern int fit_double_type (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *, const_tree);
extern int add_double_with_sign (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
unsigned HOST_WIDE_INT, HOST_WIDE_INT,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
bool);
#define add_double(l1,h1,l2,h2,lv,hv) \
add_double_with_sign (l1, h1, l2, h2, lv, hv, false)
extern int neg_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
extern int mul_double_with_sign (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
unsigned HOST_WIDE_INT, HOST_WIDE_INT,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
bool);
#define mul_double(l1,h1,l2,h2,lv,hv) \
mul_double_with_sign (l1, h1, l2, h2, lv, hv, false)
extern void lshift_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
HOST_WIDE_INT, unsigned int,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *, bool);
extern void rshift_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
HOST_WIDE_INT, unsigned int,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *, bool);
extern void lrotate_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
HOST_WIDE_INT, unsigned int,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
extern void rrotate_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
HOST_WIDE_INT, unsigned int,
unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
extern int div_and_round_double (enum tree_code, int, unsigned HOST_WIDE_INT,
HOST_WIDE_INT, unsigned HOST_WIDE_INT,
HOST_WIDE_INT, unsigned HOST_WIDE_INT *,
HOST_WIDE_INT *, unsigned HOST_WIDE_INT *,
HOST_WIDE_INT *);
enum operand_equal_flag
{
OEP_ONLY_CONST = 1,