At the moment we prohibit "widest_int = wide_int" and "offset_int = wide_int".
These would be correct only if the wide_int had the same precision as
widest_int and offset_int respectively, but since those precisions
don't really correspond to a particular language-level precision,
such cases should never occur in practice.
We also prohibit "wide_int = HOST_WIDE_INT" on the basis that the wide_int
would naturally get the precision of HOST_WIDE_INT, which is a host property.
However, we allowed "wide_int = widest_int" and "wide_int = offset_int".
This is always safe in the sense that, unlike "widest_int = wide_int"
and "offset_int = wide_int", they would never trigger an assertion
failure in themselves. But I think in practice they're always going to
be a mistake. The only arithmetic you can do on the resulting wide_int
is with wide_ints that have been assigned in the same way, in which case
you should be doing the arithmetic on widest_int or offset_int instead.
And if you don't want to do arithmetic, but simply want to access the value,
you should use wide_int_ref instead. This avoids unnecessary copying.
This patch adds an extra STATIC_ASSERT to trap that case and fixes
the minor fallout. The to_mpz change contains another fix: we applied
small_prec without checking whether len was the maximum value.
Also, it seems safer to use alloca now that we have the extra-wide
integer in vrp.
Putting the STATIC_ASSERTs in their own scope is a bit clunky, but a lot
of this code would be much cleaner with C++11...
Tested on x86_64-linux-gnu and included in the asm comparison. OK to install?
Thanks,
Richard
Index: gcc/emit-rtl.c
===================================================================
--- gcc/emit-rtl.c 2014-04-24 08:30:16.191670326 +0100
+++ gcc/emit-rtl.c 2014-04-24 08:30:19.117694968 +0100
@@ -535,7 +535,7 @@ lookup_const_wide_int (rtx wint)
(if TARGET_SUPPORTS_WIDE_INT). */
rtx
-immed_wide_int_const (const wide_int &v, enum machine_mode mode)
+immed_wide_int_const (const wide_int_ref &v, enum machine_mode mode)
{
unsigned int len = v.get_len ();
unsigned int prec = GET_MODE_PRECISION (mode);
Index: gcc/rtl.h
===================================================================
--- gcc/rtl.h 2014-04-24 08:30:16.191670326 +0100
+++ gcc/rtl.h 2014-04-24 08:30:19.117694968 +0100
@@ -2008,7 +2008,7 @@ extern double_int rtx_to_double_int (con
#endif
extern void cwi_output_hex (FILE *, const_rtx);
#ifndef GENERATOR_FILE
-extern rtx immed_wide_int_const (const wide_int &cst, enum machine_mode mode);
+extern rtx immed_wide_int_const (const wide_int_ref &, enum machine_mode);
#endif
#if TARGET_SUPPORTS_WIDE_INT == 0
extern rtx immed_double_const (HOST_WIDE_INT, HOST_WIDE_INT,
Index: gcc/tree-ssa-ccp.c
===================================================================
--- gcc/tree-ssa-ccp.c 2014-04-24 08:30:16.191670326 +0100
+++ gcc/tree-ssa-ccp.c 2014-04-24 08:30:19.118694976 +0100
@@ -218,7 +218,8 @@ dump_lattice_value (FILE *outf, const ch
}
else
{
- wide_int cval = wi::bit_and_not (wi::to_widest (val.value), val.mask);
+ widest_int cval = wi::bit_and_not (wi::to_widest (val.value),
+ val.mask);
fprintf (outf, "%sCONSTANT ", prefix);
print_hex (cval, outf);
fprintf (outf, " (");
@@ -1249,7 +1250,7 @@ bit_value_binop_1 (enum tree_code code,
case RROTATE_EXPR:
if (r2mask == 0)
{
- wide_int shift = r2val;
+ widest_int shift = r2val;
if (shift == 0)
{
*mask = r1mask;
@@ -1286,7 +1287,7 @@ bit_value_binop_1 (enum tree_code code,
is zero. */
if (r2mask == 0)
{
- wide_int shift = r2val;
+ widest_int shift = r2val;
if (shift == 0)
{
*mask = r1mask;
Index: gcc/tree-vrp.c
===================================================================
--- gcc/tree-vrp.c 2014-04-24 08:30:16.191670326 +0100
+++ gcc/tree-vrp.c 2014-04-24 08:30:19.119694985 +0100
@@ -3860,7 +3860,8 @@ adjust_range_with_scev (value_range_t *v
signop sgn = TYPE_SIGN (TREE_TYPE (step));
bool overflow;
- wide_int wtmp = wi::mul (wi::to_widest (step), nit, sgn, &overflow);
+ widest_int wtmp = wi::mul (wi::to_widest (step), nit, sgn,
+ &overflow);
/* If the multiplication overflowed we can't do a meaningful
adjustment. Likewise if the result doesn't fit in the type
of the induction variable. For a signed type we have to
Index: gcc/wide-int-print.cc
===================================================================
--- gcc/wide-int-print.cc 2014-04-24 08:30:16.191670326 +0100
+++ gcc/wide-int-print.cc 2014-04-24 08:30:19.120694993 +0100
@@ -34,7 +34,7 @@ along with GCC; see the file COPYING3.
(((PREC) + HOST_BITS_PER_WIDE_INT - 1) / HOST_BITS_PER_WIDE_INT)
void
-print_dec (const wide_int &wi, char *buf, signop sgn)
+print_dec (const wide_int_ref &wi, char *buf, signop sgn)
{
if (sgn == SIGNED)
print_decs (wi, buf);
@@ -43,7 +43,7 @@ print_dec (const wide_int &wi, char *buf
}
void
-print_dec (const wide_int &wi, FILE *file, signop sgn)
+print_dec (const wide_int_ref &wi, FILE *file, signop sgn)
{
if (sgn == SIGNED)
print_decs (wi, file);
@@ -56,7 +56,7 @@ print_dec (const wide_int &wi, FILE *fil
in a HWI. Other print in hex. */
void
-print_decs (const wide_int &wi, char *buf)
+print_decs (const wide_int_ref &wi, char *buf)
{
if ((wi.get_precision () <= HOST_BITS_PER_WIDE_INT)
|| (wi.get_len () == 1))
@@ -74,7 +74,7 @@ print_decs (const wide_int &wi, char *bu
in a HWI. Other print in hex. */
void
-print_decs (const wide_int &wi, FILE *file)
+print_decs (const wide_int_ref &wi, FILE *file)
{
char buf[WIDE_INT_PRINT_BUFFER_SIZE];
print_decs (wi, buf);
@@ -85,7 +85,7 @@ print_decs (const wide_int &wi, FILE *fi
in a HWI. Other print in hex. */
void
-print_decu (const wide_int &wi, char *buf)
+print_decu (const wide_int_ref &wi, char *buf)
{
if ((wi.get_precision () <= HOST_BITS_PER_WIDE_INT)
|| (wi.get_len () == 1 && !wi::neg_p (wi)))
@@ -98,7 +98,7 @@ print_decu (const wide_int &wi, char *bu
in a HWI. Other print in hex. */
void
-print_decu (const wide_int &wi, FILE *file)
+print_decu (const wide_int_ref &wi, FILE *file)
{
char buf[WIDE_INT_PRINT_BUFFER_SIZE];
print_decu (wi, buf);
@@ -106,7 +106,7 @@ print_decu (const wide_int &wi, FILE *fi
}
void
-print_hex (const wide_int &wi, char *buf)
+print_hex (const wide_int_ref &wi, char *buf)
{
int i = wi.get_len ();
@@ -136,7 +136,7 @@ print_hex (const wide_int &wi, char *buf
/* Print one big hex number to FILE. Note that some assemblers may not
accept this for large modes. */
void
-print_hex (const wide_int &wi, FILE *file)
+print_hex (const wide_int_ref &wi, FILE *file)
{
char buf[WIDE_INT_PRINT_BUFFER_SIZE];
print_hex (wi, buf);
Index: gcc/wide-int-print.h
===================================================================
--- gcc/wide-int-print.h 2014-04-24 08:30:16.191670326 +0100
+++ gcc/wide-int-print.h 2014-04-24 08:30:19.120694993 +0100
@@ -27,13 +27,13 @@ #define WIDE_INT_PRINT_BUFFER_SIZE (WIDE
/* Printing functions. */
-extern void print_dec (const wide_int &wi, char *buf, signop sgn);
-extern void print_dec (const wide_int &wi, FILE *file, signop sgn);
-extern void print_decs (const wide_int &wi, char *buf);
-extern void print_decs (const wide_int &wi, FILE *file);
-extern void print_decu (const wide_int &wi, char *buf);
-extern void print_decu (const wide_int &wi, FILE *file);
-extern void print_hex (const wide_int &wi, char *buf);
-extern void print_hex (const wide_int &wi, FILE *file);
+extern void print_dec (const wide_int_ref &wi, char *buf, signop sgn);
+extern void print_dec (const wide_int_ref &wi, FILE *file, signop sgn);
+extern void print_decs (const wide_int_ref &wi, char *buf);
+extern void print_decs (const wide_int_ref &wi, FILE *file);
+extern void print_decu (const wide_int_ref &wi, char *buf);
+extern void print_decu (const wide_int_ref &wi, FILE *file);
+extern void print_hex (const wide_int_ref &wi, char *buf);
+extern void print_hex (const wide_int_ref &wi, FILE *file);
#endif /* WIDE_INT_PRINT_H */
Index: gcc/wide-int.cc
===================================================================
--- gcc/wide-int.cc 2014-04-24 08:30:16.191670326 +0100
+++ gcc/wide-int.cc 2014-04-24 09:51:08.056774754 +0100
@@ -180,37 +180,36 @@ wi::from_buffer (const unsigned char *bu
return result;
}
-/* Sets RESULT from THIS, the sign is taken according to SGN. */
+/* Sets RESULT from X, the sign is taken according to SGN. */
void
-wi::to_mpz (wide_int x, mpz_t result, signop sgn)
+wi::to_mpz (const wide_int_ref &x, mpz_t result, signop sgn)
{
- bool negative = false;
int len = x.get_len ();
const HOST_WIDE_INT *v = x.get_val ();
- int small_prec = x.get_precision () & (HOST_BITS_PER_WIDE_INT - 1);
+ int excess = len * HOST_BITS_PER_WIDE_INT - x.get_precision ();
if (wi::neg_p (x, sgn))
{
- negative = true;
/* We use ones complement to avoid -x80..0 edge case that -
won't work on. */
- x = ~x;
+ HOST_WIDE_INT *t = XALLOCAVEC (HOST_WIDE_INT, len);
+ for (int i = 0; i < len; i++)
+ t[i] = ~v[i];
+ if (excess > 0)
+ t[len - 1] = (unsigned HOST_WIDE_INT) t[len - 1] << excess >> excess;
+ mpz_import (result, len, -1, sizeof (HOST_WIDE_INT), 0, 0, t);
+ mpz_com (result, result);
}
-
- if (sgn == UNSIGNED && small_prec)
+ else if (excess > 0)
{
- HOST_WIDE_INT t[WIDE_INT_MAX_ELTS];
-
+ HOST_WIDE_INT *t = XALLOCAVEC (HOST_WIDE_INT, len);
for (int i = 0; i < len - 1; i++)
t[i] = v[i];
- t[len-1] = zext_hwi (v[len-1], small_prec);
+ t[len - 1] = (unsigned HOST_WIDE_INT) v[len - 1] << excess >> excess;
mpz_import (result, len, -1, sizeof (HOST_WIDE_INT), 0, 0, t);
}
else
mpz_import (result, len, -1, sizeof (HOST_WIDE_INT), 0, 0, v);
-
- if (negative)
- mpz_com (result, result);
}
/* Returns VAL converted to TYPE. If WRAP is true, then out-of-range
Index: gcc/wide-int.h
===================================================================
--- gcc/wide-int.h 2014-04-24 08:30:16.191670326 +0100
+++ gcc/wide-int.h 2014-04-24 09:49:51.783075748 +0100
@@ -1018,7 +1018,8 @@ inline wide_int_storage::wide_int_storag
template <typename T>
inline wide_int_storage::wide_int_storage (const T &x)
{
- STATIC_ASSERT (!wi::int_traits<T>::host_dependent_precision);
+ { STATIC_ASSERT (!wi::int_traits<T>::host_dependent_precision); }
+ { STATIC_ASSERT (wi::int_traits<T>::precision_type != wi::CONST_PRECISION); }
WIDE_INT_REF_FOR (T) xi (x);
precision = xi.precision;
wi::copy (*this, xi);
@@ -3073,7 +3074,7 @@ gt_pch_nx (trailing_wide_ints <N> *, voi
wide_int from_buffer (const unsigned char *, unsigned int);
#ifndef GENERATOR_FILE
- void to_mpz (wide_int, mpz_t, signop);
+ void to_mpz (const wide_int_ref &, mpz_t, signop);
#endif
wide_int mask (unsigned int, bool, unsigned int);
