OpenE2K
/
gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

re PR tree-optimization/30318 (VRP does not create ANTI_RANGEs on overflow) 

gcc/
2012-08-03 Marc Glisse <marc.glisse@inria.fr>

	PR tree-optimization/30318
	* double-int.c (mul_double_wide_with_sign): New function.
	(mul_double_with_sign): Call the new function.
	* double-int.h (mul_double_wide_with_sign): Declare the new function.
	* tree-vrp.c (extract_range_from_binary_expr_1) [MULT_EXPR]:
	Handle integer types that wrap on overflow.
	(quad_int_cmp): New helper function.
	(quad_int_pair_sort): Likewise.


gcc/testsuite/
2012-08-03 Marc Glisse <marc.glisse@inria.fr>

	PR tree-optimization/30318
	* gcc.dg/tree-ssa/vrp77.c: New testcase.

From-SVN: r190125
This commit is contained in:
Marc Glisse 2012-08-03 14:21:14 +02:00 committed by Marc Glisse
parent 11f359257e
commit 4e7c4b7301
6 changed files with 229 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
gcc/ChangeLog
View File

@ -1,3 +1,14 @@
2012-08-03 Marc Glisse <marc.glisse@inria.fr>
PR tree-optimization/30318
* double-int.c (mul_double_wide_with_sign): New function.
(mul_double_with_sign): Call the new function.
* double-int.h (mul_double_wide_with_sign): Declare the new function.
* tree-vrp.c (extract_range_from_binary_expr_1) [MULT_EXPR]:
Handle integer types that wrap on overflow.
(quad_int_cmp): New helper function.
(quad_int_pair_sort): Likewise.
2012-08-03 Richard Guenther <rguenther@suse.de>
* tree-vect-loop-manip.c (vect_can_advance_ivs_p): Query

29
gcc/double-int.c
View File

@ -134,14 +134,29 @@ 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)
{
unsigned HOST_WIDE_INT toplow;
HOST_WIDE_INT tophigh;
return mul_double_wide_with_sign (l1, h1, l2, h2,
lv, hv, &toplow, &tophigh,
unsigned_p);
}
int
mul_double_wide_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,
unsigned HOST_WIDE_INT *lw, HOST_WIDE_INT *hw,
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;
unsigned HOST_WIDE_INT neglow;
HOST_WIDE_INT neghigh;
encode (arg1, l1, h1);
encode (arg2, l2, h2);
@ -165,25 +180,25 @@ mul_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
}
decode (prod, lv, hv);
decode (prod + 4, &toplow, &tophigh);
decode (prod + 4, lw, hw);
/* Unsigned overflow is immediate. */
if (unsigned_p)
return (toplow | tophigh) != 0;
return (*lw | *hw) != 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);
add_double (neglow, neghigh, *lw, *hw, lw, hw);
}
if (h2 < 0)
{
neg_double (l1, h1, &neglow, &neghigh);
add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
add_double (neglow, neghigh, *lw, *hw, lw, hw);
}
return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
return (*hv < 0 ? ~(*lw & *hw) : *lw | *hw) != 0;
}
/* Shift the doubleword integer in L1, H1 right by COUNT places

5
gcc/double-int.h
View File

@ -307,6 +307,11 @@ 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);
extern int mul_double_wide_with_sign (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 *,
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,

5
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,8 @@
2012-08-03 Marc Glisse <marc.glisse@inria.fr>
PR tree-optimization/30318
* gcc.dg/tree-ssa/vrp77.c: New testcase.
2012-08-03 Marc Glisse <marc.glisse@inria.fr>
* g++.dg/ext/vector17.C: New testcase.

47
gcc/testsuite/gcc.dg/tree-ssa/vrp77.c Normal file
View File

@ -0,0 +1,47 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-optimized" } */
#ifdef __SIZEOF_INT128__
#define T __int128
#else
#define T long long
#endif
extern void impossible (void);
void f(T x)
{
unsigned T y;
unsigned T z;
if (x < -7)
return;
if (x > 2)
return;
y = x;
z = y * y;
if (z == 666)
impossible ();
}
void g(unsigned T x)
{
unsigned T y;
unsigned T z;
unsigned T m = -1;
m = m / 2;
if (x < m-2)
return;
if (x > m-1)
return;
y = x;
z = y * y;
/* The product (ignoring it is a square) has only 3 possible values:
4, 9 and 2^127+6. At least one of the values 7, 666 and -666 is
known to be impossible. 7 is the most logical in the current
implementation. */
if (z == 7)
impossible ();
}
/* { dg-final { scan-tree-dump-not "impossible" "optimized" } } */
/* { dg-final { cleanup-tree-dump "optimized" } } */

139
gcc/tree-vrp.c
View File

@ -2188,6 +2188,28 @@ extract_range_from_multiplicative_op_1 (value_range_t *vr,
set_value_range (vr, type, min, max, NULL);
}
/* Some quadruple precision helpers. */
static int
quad_int_cmp (double_int l0, double_int h0,
double_int l1, double_int h1, bool uns)
{
int c = double_int_cmp (h0, h1, uns);
if (c != 0) return c;
return double_int_ucmp (l0, l1);
}
static void
quad_int_pair_sort (double_int *l0, double_int *h0,
double_int *l1, double_int *h1, bool uns)
{
if (quad_int_cmp (*l0, *h0, *l1, *h1, uns) > 0)
{
double_int tmp;
tmp = *l0; *l0 = *l1; *l1 = tmp;
tmp = *h0; *h0 = *h1; *h1 = tmp;
}
}
/* Extract range information from a binary operation CODE based on
the ranges of each of its operands, *VR0 and *VR1 with resulting
type EXPR_TYPE. The resulting range is stored in *VR. */
@ -2569,6 +2591,123 @@ extract_range_from_binary_expr_1 (value_range_t *vr,
}
else if (code == MULT_EXPR)
{
/* Fancy code so that with unsigned, [-3,-1]*[-3,-1] does not
drop to varying. */
if (range_int_cst_p (&vr0)
&& range_int_cst_p (&vr1)
&& TYPE_OVERFLOW_WRAPS (expr_type))
{
double_int min0, max0, min1, max1, sizem1, size;
double_int prod0l, prod0h, prod1l, prod1h,
prod2l, prod2h, prod3l, prod3h;
bool uns0, uns1, uns;
sizem1 = double_int_max_value (TYPE_PRECISION (expr_type), true);
size = double_int_add (sizem1, double_int_one);
min0 = tree_to_double_int (vr0.min);
max0 = tree_to_double_int (vr0.max);
min1 = tree_to_double_int (vr1.min);
max1 = tree_to_double_int (vr1.max);
uns0 = TYPE_UNSIGNED (expr_type);
uns1 = uns0;
/* Canonicalize the intervals. */
if (TYPE_UNSIGNED (expr_type))
{
double_int min2 = double_int_sub (size, min0);
if (double_int_cmp (min2, max0, true) < 0)
{
min0 = double_int_neg (min2);
max0 = double_int_sub (max0, size);
uns0 = false;
}
min2 = double_int_sub (size, min1);
if (double_int_cmp (min2, max1, true) < 0)
{
min1 = double_int_neg (min2);
max1 = double_int_sub (max1, size);
uns1 = false;
}
}
uns = uns0 & uns1;
mul_double_wide_with_sign (min0.low, min0.high,
min1.low, min1.high,
&prod0l.low, &prod0l.high,
&prod0h.low, &prod0h.high, true);
if (!uns0 && double_int_negative_p (min0))
prod0h = double_int_sub (prod0h, min1);
if (!uns1 && double_int_negative_p (min1))
prod0h = double_int_sub (prod0h, min0);
mul_double_wide_with_sign (min0.low, min0.high,
max1.low, max1.high,
&prod1l.low, &prod1l.high,
&prod1h.low, &prod1h.high, true);
if (!uns0 && double_int_negative_p (min0))
prod1h = double_int_sub (prod1h, max1);
if (!uns1 && double_int_negative_p (max1))
prod1h = double_int_sub (prod1h, min0);
mul_double_wide_with_sign (max0.low, max0.high,
min1.low, min1.high,
&prod2l.low, &prod2l.high,
&prod2h.low, &prod2h.high, true);
if (!uns0 && double_int_negative_p (max0))
prod2h = double_int_sub (prod2h, min1);
if (!uns1 && double_int_negative_p (min1))
prod2h = double_int_sub (prod2h, max0);
mul_double_wide_with_sign (max0.low, max0.high,
max1.low, max1.high,
&prod3l.low, &prod3l.high,
&prod3h.low, &prod3h.high, true);
if (!uns0 && double_int_negative_p (max0))
prod3h = double_int_sub (prod3h, max1);
if (!uns1 && double_int_negative_p (max1))
prod3h = double_int_sub (prod3h, max0);
/* Sort the 4 products. */
quad_int_pair_sort (&prod0l, &prod0h, &prod3l, &prod3h, uns);
quad_int_pair_sort (&prod1l, &prod1h, &prod2l, &prod2h, uns);
quad_int_pair_sort (&prod0l, &prod0h, &prod1l, &prod1h, uns);
quad_int_pair_sort (&prod2l, &prod2h, &prod3l, &prod3h, uns);
/* Max - min. */
if (double_int_zero_p (prod0l))
{
prod1l = double_int_zero;
prod1h = double_int_neg (prod0h);
}
else
{
prod1l = double_int_neg (prod0l);
prod1h = double_int_not (prod0h);
}
prod2l = double_int_add (prod3l, prod1l);
prod2h = double_int_add (prod3h, prod1h);
if (double_int_ucmp (prod2l, prod3l) < 0)
prod2h = double_int_add (prod2h, double_int_one); /* carry */
if (!double_int_zero_p (prod2h)
|| double_int_cmp (prod2l, sizem1, true) >= 0)
{
/* the range covers all values. */
set_value_range_to_varying (vr);
return;
}
/* The following should handle the wrapping and selecting
VR_ANTI_RANGE for us. */
min = double_int_to_tree (expr_type, prod0l);
max = double_int_to_tree (expr_type, prod3l);
set_and_canonicalize_value_range (vr, VR_RANGE, min, max, NULL);
return;
}
/* If we have an unsigned MULT_EXPR with two VR_ANTI_RANGEs,
drop to VR_VARYING. It would take more effort to compute a
precise range for such a case. For example, if we have