https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88784
--- Comment #20 from Qi Feng <ffengqi at gcc dot gnu.org> ---
I have tried to merge signed and unsigned together:
/* x > y && x != ( 0 or XXX_MIN ) --> x > y */
(for and (truth_and bit_and)
(simplify
(and:c (gt:c@3 @0 @1) (ne @0 INTEGER_CST@2))
(if (INTEGRAL_TYPE_P (TREE_TYPE(@0)) && INTEGRAL_TYPE_P (TREE_TYPE(@1)))
(if ((TYPE_UNSIGNED (TREE_TYPE(@0)) && TYPE_UNSIGNED (TREE_TYPE(@1))
&& integer_zerop (@2))
|| (!TYPE_UNSIGNED (TREE_TYPE(@0)) && !TYPE_UNSIGNED (TREE_TYPE(@1))
&& wi::eq_p (wi::to_wide (@2),
wi::min_value (TYPE_PRECISION (TREE_TYPE (@2)),
SIGNED))))
@3))))
/* x > y || x != ( 0 or XXX_MIN ) --> x != ( 0 or XXX_MIN ) */
(for or (truth_or bit_ior)
(simplify
(or:c (gt:c @0 @1) (ne@3 @0 INTEGER_CST@2))
(if (INTEGRAL_TYPE_P (TREE_TYPE(@0)) && INTEGRAL_TYPE_P (TREE_TYPE(@1)))
(if ((TYPE_UNSIGNED (TREE_TYPE(@0)) && TYPE_UNSIGNED (TREE_TYPE(@1))
&& integer_zerop (@2))
|| (!TYPE_UNSIGNED (TREE_TYPE(@0)) && !TYPE_UNSIGNED (TREE_TYPE(@1))
&& wi::eq_p (wi::to_wide (@2),
wi::min_value (TYPE_PRECISION (TREE_TYPE (@2)),
SIGNED))))
@3))))
/* x < y && x != ( UXXX_MAX or XXX_MAX ) --> x < y */
(for and (truth_and bit_and)
(simplify
(and:c (lt:c@3 @0 @1) (ne @0 INTEGER_CST@2))
(if (INTEGRAL_TYPE_P (TREE_TYPE(@0)) && INTEGRAL_TYPE_P (TREE_TYPE(@1)))
(if ((TYPE_UNSIGNED (TREE_TYPE(@0)) && TYPE_UNSIGNED (TREE_TYPE(@1))
&& wi::eq_p (wi::to_wide (@2),
wi::max_value (TYPE_PRECISION (TREE_TYPE (@2)),
UNSIGNED)))
|| (!TYPE_UNSIGNED (TREE_TYPE(@0)) && !TYPE_UNSIGNED (TREE_TYPE(@1))
&& wi::eq_p (wi::to_wide (@2),
wi::max_value (TYPE_PRECISION (TREE_TYPE (@2)),
SIGNED))))
@3))))
(That's not all of them, for that would be too long and I think it's not
necessary.)
I also tried it on a x86 laptop, seems it does work. But I got a bootstrap
issue. I don't know if it's caused by my patch or the version of gcc I used to
compile.
Another problem is that I can't craft some c/c++ code to test truth_and. Maybe
it's used by other languages? Is it necessary to use truth_and along side
bit_and?
I have to make this work on a ppc64le machine, could you give me some hints of
where to look into?
BTW, the following tests may be useful if you want test it on your machine:
#include <limits.h>
/* x > y && x != ( 0 or INT_MIN ) --> x > y */
_Bool f0 (unsigned x, unsigned y)
{
return x > y && x != 0;
}
_Bool f1 (unsigned x, unsigned y)
{
return y < x && x != 0;
}
_Bool f2 (unsigned x, unsigned y)
{
return x != 0 && x > y;
}
_Bool f3 (unsigned x, unsigned y)
{
return x != 0 && y < x;
}
_Bool f4 (int x, int y)
{
return x > y && x != INT_MIN;
}
_Bool f5 (int x, int y)
{
return y < x && x != INT_MIN;
}
_Bool f6 (int x, int y)
{
return x != INT_MIN && x > y;
}
_Bool f7 (int x, int y)
{
return x != INT_MIN && y < x;
}
_Bool f8 (unsigned char x, unsigned char y)
{
return x > y && x != 0;
}
/* x > y || x != ( 0 or XXX_MIN ) --> x != ( 0 or XXX_MIN ) */
_Bool f10 (unsigned x, unsigned y)
{
return x > y || x != 0;
}
_Bool f11 (int x, int y)
{
return x > y || x != INT_MIN;
}
_Bool f12 (unsigned char x, unsigned char y)
{
return x > y || x != 0;
}
_Bool f13 (signed char x, signed char y)
{
return x > y || x != SCHAR_MIN;
}
/* x < y && x != ( UXXX_MAX or XXX_MAX ) --> x < y */
_Bool f20 (unsigned x, unsigned y)
{
return x < y && x != UINT_MAX;
}
_Bool f21 (int x, int y)
{
return x < y && x != INT_MAX;
}
_Bool f22 (unsigned char x, unsigned char y)
{
return x < y && x != UCHAR_MAX;
}
_Bool f23 (signed char x, signed char y)
{
return x < y && x != SCHAR_MIN;
}
