On Mon, Nov 29, 2021 at 4:40 PM Richard Sandiford
<richard.sandif...@arm.com> wrote:
>
> Sorry for the slow response, was away last week.
>
> Richard Biener <richard.guent...@gmail.com> writes:
> > On Wed, Nov 10, 2021 at 1:50 PM Richard Sandiford via Gcc-patches
> > <gcc-patches@gcc.gnu.org> wrote:
> >>
> >> This patch uses information about internal functions to canonicalize
> >> the argument order of calls.
> >>
> >> Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
> >
> > OK. Note the gimple_resimplifyN functions also canonicalize operand
> > order, currently for is_tree_code only:
> >
> > /* Canonicalize operand order. */
> > bool canonicalized = false;
> > if (res_op->code.is_tree_code ()
> > && (TREE_CODE_CLASS ((enum tree_code) res_op->code) == tcc_comparison
> > || commutative_tree_code (res_op->code))
> > && tree_swap_operands_p (res_op->ops[0], res_op->ops[1]))
> > {
> > std::swap (res_op->ops[0], res_op->ops[1]);
> > if (TREE_CODE_CLASS ((enum tree_code) res_op->code) == tcc_comparison)
> > res_op->code = swap_tree_comparison (res_op->code);
> > canonicalized = true;
> > }
> >
> > that's maybe not the best place. The function assumes the operands
> > are already valueized,
> > so it maybe should be valueization that does the canonicalization -
> > but I think doing it
> > elsewhere made operand order unreliable (we do end up with
> > non-canonical order in
> > the IL sometimes).
> >
> > So maybe you should amend the code in resimplifyN as well.
>
> Hmm, yeah, thanks for the heads up. Does this updated version look OK?
> Tested as before.
Yes - OK.
Thanks,
Richard.
> Thanks,
> Richard
>
>
> gcc/
> * gimple-fold.c: Include internal-fn.h.
> (fold_stmt_1): If a function maps to an internal one, use
> first_commutative_argument to canonicalize the order of
> commutative arguments.
> * gimple-match-head.c (gimple_resimplify2, gimple_resimplify3)
> (gimple_resimplify4, gimple_resimplify5): Extend commutativity
> checks to functions.
>
> gcc/testsuite/
> * gcc.dg/fmax-fmin-1.c: New test.
> ---
> gcc/gimple-fold.c | 25 ++++++++++++--
> gcc/gimple-match-head.c | 52 ++++++++++++++++++++----------
> gcc/testsuite/gcc.dg/fmax-fmin-1.c | 18 +++++++++++
> 3 files changed, 75 insertions(+), 20 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/fmax-fmin-1.c
>
> diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
> index 44fba12e150..1d8fd74f72c 100644
> --- a/gcc/gimple-fold.c
> +++ b/gcc/gimple-fold.c
> @@ -69,6 +69,7 @@ along with GCC; see the file COPYING3. If not see
> #include "varasm.h"
> #include "memmodel.h"
> #include "optabs.h"
> +#include "internal-fn.h"
>
> enum strlen_range_kind {
> /* Compute the exact constant string length. */
> @@ -6109,18 +6110,36 @@ fold_stmt_1 (gimple_stmt_iterator *gsi, bool inplace,
> tree (*valueize) (tree))
> break;
> case GIMPLE_CALL:
> {
> - for (i = 0; i < gimple_call_num_args (stmt); ++i)
> + gcall *call = as_a<gcall *> (stmt);
> + for (i = 0; i < gimple_call_num_args (call); ++i)
> {
> - tree *arg = gimple_call_arg_ptr (stmt, i);
> + tree *arg = gimple_call_arg_ptr (call, i);
> if (REFERENCE_CLASS_P (*arg)
> && maybe_canonicalize_mem_ref_addr (arg))
> changed = true;
> }
> - tree *lhs = gimple_call_lhs_ptr (stmt);
> + tree *lhs = gimple_call_lhs_ptr (call);
> if (*lhs
> && REFERENCE_CLASS_P (*lhs)
> && maybe_canonicalize_mem_ref_addr (lhs))
> changed = true;
> + if (*lhs)
> + {
> + combined_fn cfn = gimple_call_combined_fn (call);
> + internal_fn ifn = associated_internal_fn (cfn, TREE_TYPE (*lhs));
> + int opno = first_commutative_argument (ifn);
> + if (opno >= 0)
> + {
> + tree arg1 = gimple_call_arg (call, opno);
> + tree arg2 = gimple_call_arg (call, opno + 1);
> + if (tree_swap_operands_p (arg1, arg2))
> + {
> + gimple_call_set_arg (call, opno, arg2);
> + gimple_call_set_arg (call, opno + 1, arg1);
> + changed = true;
> + }
> + }
> + }
> break;
> }
> case GIMPLE_ASM:
> diff --git a/gcc/gimple-match-head.c b/gcc/gimple-match-head.c
> index c481a625581..2d9364ca5de 100644
> --- a/gcc/gimple-match-head.c
> +++ b/gcc/gimple-match-head.c
> @@ -294,18 +294,16 @@ gimple_resimplify2 (gimple_seq *seq, gimple_match_op
> *res_op,
>
> /* Canonicalize operand order. */
> bool canonicalized = false;
> - if (res_op->code.is_tree_code ())
> + bool is_comparison
> + = (res_op->code.is_tree_code ()
> + && TREE_CODE_CLASS (tree_code (res_op->code)) == tcc_comparison);
> + if ((is_comparison || commutative_binary_op_p (res_op->code, res_op->type))
> + && tree_swap_operands_p (res_op->ops[0], res_op->ops[1]))
> {
> - auto code = tree_code (res_op->code);
> - if ((TREE_CODE_CLASS (code) == tcc_comparison
> - || commutative_tree_code (code))
> - && tree_swap_operands_p (res_op->ops[0], res_op->ops[1]))
> - {
> - std::swap (res_op->ops[0], res_op->ops[1]);
> - if (TREE_CODE_CLASS (code) == tcc_comparison)
> - res_op->code = swap_tree_comparison (code);
> - canonicalized = true;
> - }
> + std::swap (res_op->ops[0], res_op->ops[1]);
> + if (is_comparison)
> + res_op->code = swap_tree_comparison (tree_code (res_op->code));
> + canonicalized = true;
> }
>
> /* Limit recursion, see gimple_resimplify1. */
> @@ -376,11 +374,11 @@ gimple_resimplify3 (gimple_seq *seq, gimple_match_op
> *res_op,
>
> /* Canonicalize operand order. */
> bool canonicalized = false;
> - if (res_op->code.is_tree_code ()
> - && commutative_ternary_tree_code (tree_code (res_op->code))
> - && tree_swap_operands_p (res_op->ops[0], res_op->ops[1]))
> + int argno = first_commutative_argument (res_op->code, res_op->type);
> + if (argno >= 0
> + && tree_swap_operands_p (res_op->ops[argno], res_op->ops[argno + 1]))
> {
> - std::swap (res_op->ops[0], res_op->ops[1]);
> + std::swap (res_op->ops[argno], res_op->ops[argno + 1]);
> canonicalized = true;
> }
>
> @@ -424,6 +422,16 @@ gimple_resimplify4 (gimple_seq *seq, gimple_match_op
> *res_op,
> {
> /* No constant folding is defined for four-operand functions. */
>
> + /* Canonicalize operand order. */
> + bool canonicalized = false;
> + int argno = first_commutative_argument (res_op->code, res_op->type);
> + if (argno >= 0
> + && tree_swap_operands_p (res_op->ops[argno], res_op->ops[argno + 1]))
> + {
> + std::swap (res_op->ops[argno], res_op->ops[argno + 1]);
> + canonicalized = true;
> + }
> +
> /* Limit recursion, see gimple_resimplify1. */
> static unsigned depth;
> if (depth > 10)
> @@ -450,7 +458,7 @@ gimple_resimplify4 (gimple_seq *seq, gimple_match_op
> *res_op,
> if (maybe_resimplify_conditional_op (seq, res_op, valueize))
> return true;
>
> - return false;
> + return canonicalized;
> }
>
> /* Helper that matches and simplifies the toplevel result from
> @@ -465,6 +473,16 @@ gimple_resimplify5 (gimple_seq *seq, gimple_match_op
> *res_op,
> {
> /* No constant folding is defined for five-operand functions. */
>
> + /* Canonicalize operand order. */
> + bool canonicalized = false;
> + int argno = first_commutative_argument (res_op->code, res_op->type);
> + if (argno >= 0
> + && tree_swap_operands_p (res_op->ops[argno], res_op->ops[argno + 1]))
> + {
> + std::swap (res_op->ops[argno], res_op->ops[argno + 1]);
> + canonicalized = true;
> + }
> +
> gimple_match_op res_op2 (*res_op);
> if (gimple_simplify (&res_op2, seq, valueize,
> res_op->code, res_op->type,
> @@ -478,7 +496,7 @@ gimple_resimplify5 (gimple_seq *seq, gimple_match_op
> *res_op,
> if (maybe_resimplify_conditional_op (seq, res_op, valueize))
> return true;
>
> - return false;
> + return canonicalized;
> }
>
> /* Match and simplify the toplevel valueized operation THIS.
> diff --git a/gcc/testsuite/gcc.dg/fmax-fmin-1.c
> b/gcc/testsuite/gcc.dg/fmax-fmin-1.c
> new file mode 100644
> index 00000000000..e7e0518d8bb
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/fmax-fmin-1.c
> @@ -0,0 +1,18 @@
> +/* { dg-options "-O -fdump-tree-optimized" } */
> +
> +void
> +f1 (double *res, double x, double y)
> +{
> + res[0] = __builtin_fmax (x, y);
> + res[1] = __builtin_fmax (y, x);
> +}
> +
> +void
> +f2 (double *res, double x, double y)
> +{
> + res[0] = __builtin_fmin (x, y);
> + res[1] = __builtin_fmin (y, x);
> +}
> +
> +/* { dg-final { scan-tree-dump-times {__builtin_fmax} 1 "optimized" } } */
> +/* { dg-final { scan-tree-dump-times {__builtin_fmin} 1 "optimized" } } */
> --
> 2.25.1
>
