On Tue, Aug 8, 2023 at 2:55 AM Andrew Pinski via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> This adds a simple match pattern for this case.
> I noticed it a couple of different places.
> One while I was looking at code generation of a parser and
> also while I was looking at locations where bitwise_inverted_equal_p
> should be used more.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
>
> PR tree-optimization/110937
> PR tree-optimization/100798
>
> gcc/ChangeLog:
>
> * match.pd (`a ? ~b : b`): Handle this
> case.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/tree-ssa/bool-14.c: New test.
> * gcc.dg/tree-ssa/bool-15.c: New test.
> * gcc.dg/tree-ssa/phi-opt-33.c: New test.
> * gcc.dg/tree-ssa/20030709-2.c: Update testcase
> so `a ? -1 : 0` is not used to hit the match
> pattern.
> ---
> gcc/match.pd | 13 +++++++++++++
> gcc/testsuite/gcc.dg/tree-ssa/20030709-2.c | 5 +++--
> gcc/testsuite/gcc.dg/tree-ssa/bool-14.c | 15 +++++++++++++++
> gcc/testsuite/gcc.dg/tree-ssa/bool-15.c | 18 ++++++++++++++++++
> gcc/testsuite/gcc.dg/tree-ssa/phi-opt-33.c | 13 +++++++++++++
> 5 files changed, 62 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/bool-14.c
> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/bool-15.c
> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/phi-opt-33.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 9b4819e5be7..f887c517c81 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -6460,6 +6460,19 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> (if (cmp == NE_EXPR)
> { constant_boolean_node (true, type); })))))))
>
> +#if GIMPLE
> +/* a?~t:t -> (-(a))^t */
> +(simplify
> + (cond @0 @1 @2)
> + (if (bitwise_inverted_equal_p (@1, @2))
I'm not sure if that can ever match a not INTEGRAL_TYPE_P
but we can have vector typed @1 and @2 and then the
TYPE_PRECISION ask below would be wrong. So can you
add
INTEGRAL_TYPE_P (type)
&& bitwise_in...
if only for clarity?
> + (with {
> + auto prec = TYPE_PRECISION (type);
> + auto unsign = TYPE_UNSIGNED (type);
> + tree inttype = build_nonstandard_integer_type (prec, unsign);
> + }
> + (convert (bit_xor (negate (convert:inttype @0)) (convert:inttype @2))))))
so we don't get to know which of @1 or @2 is "simpler" (the not
explicitely inverted
operand), I suppose that's the disadvantage of using bitwise_inverted_equal_p.
I'll note that if you make bitwise_inverted_equal_p a match you'd need a :c on
the 'cond' but otherwise complexity would be the same as match patterns are not
"inlined".
In any case, OK with the INTEGRAL_TYPE_P check.
Thanks,
Richard.
> +#endif
> +
> /* Simplify pointer equality compares using PTA. */
> (for neeq (ne eq)
> (simplify
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/20030709-2.c
> b/gcc/testsuite/gcc.dg/tree-ssa/20030709-2.c
> index 5009cd69cfe..78938f919d4 100644
> --- a/gcc/testsuite/gcc.dg/tree-ssa/20030709-2.c
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/20030709-2.c
> @@ -29,15 +29,16 @@ union tree_node
> };
> int make_decl_rtl (tree, int);
> void *
> -get_alias_set (t)
> +get_alias_set (t, t1)
> tree t;
> + void *t1;
> {
> long set;
> if (t->decl.rtl)
> return (t->decl.rtl->fld[1].rtmem
> ? 0
> : (((t->decl.rtl ? t->decl.rtl: (make_decl_rtl (t, 0),
> t->decl.rtl)))->fld[1]).rtmem);
> - return (void*)-1;
> + return t1;
> }
>
> /* There should be precisely one load of ->decl.rtl. If there is
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/bool-14.c
> b/gcc/testsuite/gcc.dg/tree-ssa/bool-14.c
> new file mode 100644
> index 00000000000..0149380a63b
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/bool-14.c
> @@ -0,0 +1,15 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized-raw" } */
> +/* PR tree-optimization/110937 */
> +
> +_Bool f2(_Bool a, _Bool b)
> +{
> + if (a)
> + return !b;
> + return b;
> +}
> +
> +/* We should be able to remove the conditional and convert it to an xor. */
> +/* { dg-final { scan-tree-dump-not "gimple_cond " "optimized" } } */
> +/* { dg-final { scan-tree-dump-not "gimple_phi " "optimized" } } */
> +/* { dg-final { scan-tree-dump-times "bit_xor_expr, " 1 "optimized" } } */
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/bool-15.c
> b/gcc/testsuite/gcc.dg/tree-ssa/bool-15.c
> new file mode 100644
> index 00000000000..1f496663863
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/bool-15.c
> @@ -0,0 +1,18 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized-raw" } */
> +/* PR tree-optimization/110937 */
> +
> +_Bool f2(int x, int y, int w, int z)
> +{
> + _Bool a = x == y;
> + _Bool b = w == z;
> + if (a)
> + return !b;
> + return b;
> +}
> +
> +/* We should be able to remove the conditional and convert it to an xor. */
> +/* { dg-final { scan-tree-dump-not "gimple_cond " "optimized" } } */
> +/* { dg-final { scan-tree-dump-not "gimple_phi " "optimized" } } */
> +/* { dg-final { scan-tree-dump-not "ne_expr, " "optimized" } } */
> +/* { dg-final { scan-tree-dump-times "bit_xor_expr, " 1 "optimized" } } */
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-33.c
> b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-33.c
> new file mode 100644
> index 00000000000..b79fe44187a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-33.c
> @@ -0,0 +1,13 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized-raw" } */
> +/* PR tree-optimization/100798 */
> +
> +int f(int a, int t)
> +{
> + return (a=='s' ? ~t : t);
> +}
> +
> +/* This should be convert into t^-(a=='s'). */
> +/* { dg-final { scan-tree-dump-times "bit_xor_expr, " 1 "optimized" } } */
> +/* { dg-final { scan-tree-dump-times "negate_expr, " 1 "optimized" } } */
> +/* { dg-final { scan-tree-dump-not "bit_not_expr, " "optimized" } } */
> --
> 2.31.1
>
