[PATCH 1/4] Canonicalize argument order for commutative functions
Richard Sandiford
richard.sandiford@arm.com
Mon Nov 29 15:40:07 GMT 2021
Sorry for the slow response, was away last week.
Richard Biener <richard.guenther@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.
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
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