On Mon, Jul 31, 2023 at 3:53 AM Richard Biener via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On Mon, Jul 31, 2023 at 7:35 AM Andrew Pinski via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
> >
> > Even though these are done by combine_comparisons, we can add them to match
> > to allow simplifcations during match rather than just during
> > reassoc/ifcombine.
> >
> > OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
>
> OK. Note we want to get rid of the GENERIC folding parts of
> maybe_fold_{and,or}_comparisons which is what those passes rely on.
Yes that was the idea here but there are still a few more cases that
need to be handled: Floating point, and some integer constants due to
`a <= 1` changing to `a < 0`.
Thanks,
Andrew
>
> Richard.
>
> > gcc/ChangeLog:
> >
> > PR tree-optimization/106164
> > * match.pd (`a != b & a <= b`, `a != b & a >= b`,
> > `a == b | a < b`, `a == b | a > b`): Handle these cases
> > too.
> >
> > gcc/testsuite/ChangeLog:
> >
> > PR tree-optimization/106164
> > * gcc.dg/tree-ssa/cmpbit-2.c: New test.
> > ---
> > gcc/match.pd | 32 +++++++++++++++++--
> > gcc/testsuite/gcc.dg/tree-ssa/cmpbit-2.c | 39 ++++++++++++++++++++++++
> > 2 files changed, 69 insertions(+), 2 deletions(-)
> > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/cmpbit-2.c
> >
> > diff --git a/gcc/match.pd b/gcc/match.pd
> > index 00af5d99119..cf8057701ea 100644
> > --- a/gcc/match.pd
> > +++ b/gcc/match.pd
> > @@ -2832,7 +2832,21 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> > (switch
> > (if (code1 == EQ_EXPR && val) @3)
> > (if (code1 == EQ_EXPR && !val) { constant_boolean_node (false,
> > type); })
> > - (if (code1 == NE_EXPR && !val) @4)))))))
> > + (if (code1 == NE_EXPR && !val) @4)
> > + (if (code1 == NE_EXPR
> > + && code2 == GE_EXPR
> > + && cmp == 0)
> > + (gt @0 @1))
> > + (if (code1 == NE_EXPR
> > + && code2 == LE_EXPR
> > + && cmp == 0)
> > + (lt @0 @1))
> > + )
> > + )
> > + )
> > + )
> > + )
> > +)
> >
> > /* Convert (X OP1 CST1) && (X OP2 CST2).
> > Convert (X OP1 Y) && (X OP2 Y). */
> > @@ -2917,7 +2931,21 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> > (switch
> > (if (code1 == EQ_EXPR && val) @4)
> > (if (code1 == NE_EXPR && val) { constant_boolean_node (true, type);
> > })
> > - (if (code1 == NE_EXPR && !val) @3)))))))
> > + (if (code1 == NE_EXPR && !val) @3)
> > + (if (code1 == EQ_EXPR
> > + && code2 == GT_EXPR
> > + && cmp == 0)
> > + (ge @0 @1))
> > + (if (code1 == EQ_EXPR
> > + && code2 == LT_EXPR
> > + && cmp == 0)
> > + (le @0 @1))
> > + )
> > + )
> > + )
> > + )
> > + )
> > +)
> >
> > /* Convert (X OP1 CST1) || (X OP2 CST2).
> > Convert (X OP1 Y) || (X OP2 Y). */
> > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-2.c
> > b/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-2.c
> > new file mode 100644
> > index 00000000000..c4226ef01af
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-2.c
> > @@ -0,0 +1,39 @@
> > +/* { dg-do compile } */
> > +/* { dg-options "-O1 -fno-tree-reassoc -fdump-tree-optimized-raw" } */
> > +
> > +_Bool f(int a, int b)
> > +{
> > + _Bool c = a == b;
> > + _Bool d = a > b;
> > + return c | d;
> > +}
> > +
> > +_Bool f1(int a, int b)
> > +{
> > + _Bool c = a != b;
> > + _Bool d = a >= b;
> > + return c & d;
> > +}
> > +
> > +_Bool g(int a, int b)
> > +{
> > + _Bool c = a == b;
> > + _Bool d = a < b;
> > + return c | d;
> > +}
> > +
> > +_Bool g1(int a, int b)
> > +{
> > + _Bool c = a != b;
> > + _Bool d = a <= b;
> > + return c & d;
> > +}
> > +
> > +
> > +/* We should be able to optimize these without reassociation too. */
> > +/* { dg-final { scan-tree-dump-not "bit_and_expr," "optimized" } } */
> > +/* { dg-final { scan-tree-dump-not "bit_ior_expr," "optimized" } } */
> > +/* { dg-final { scan-tree-dump-times "gt_expr," 1 "optimized" } } */
> > +/* { dg-final { scan-tree-dump-times "ge_expr," 1 "optimized" } } */
> > +/* { dg-final { scan-tree-dump-times "lt_expr," 1 "optimized" } } */
> > +/* { dg-final { scan-tree-dump-times "le_expr," 1 "optimized" } } */
> > --
> > 2.31.1
> >
