* [PATCH] unswitch: Fold case label lo/hi values to index type [PR105770]
@ 2022-05-31 9:32 Jakub Jelinek
2022-05-31 9:52 ` Richard Biener
0 siblings, 1 reply; 2+ messages in thread
From: Jakub Jelinek @ 2022-05-31 9:32 UTC (permalink / raw)
To: Richard Biener; +Cc: gcc-patches
Hi!
The following testcase ICEs because we use different types in comparison,
idx has int type, while CASE_LOW has char type.
While I believe all CASE_{LOW,HIGH} in the same switch have to use the same
or compatible type, the index expression can have a promoted type as happens
in this testcase. Other spots that handle switches do such foldings too.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2022-05-31 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/105770
* tree-ssa-loop-unswitch.cc (find_unswitching_predicates_for_bb): Cast
CASE_LOW and CASE_HIGH to TREE_TYPE (idx) before comparisons with idx.
* gcc.dg/pr105770.c: New test.
--- gcc/tree-ssa-loop-unswitch.cc.jj 2022-05-25 11:07:29.754185772 +0200
+++ gcc/tree-ssa-loop-unswitch.cc 2022-05-30 10:57:23.165131441 +0200
@@ -494,6 +494,7 @@ find_unswitching_predicates_for_bb (basi
{
unsigned nlabels = gimple_switch_num_labels (stmt);
tree idx = gimple_switch_index (stmt);
+ tree idx_type = TREE_TYPE (idx);
if (TREE_CODE (idx) != SSA_NAME
|| nlabels < 1)
return;
@@ -526,16 +527,18 @@ find_unswitching_predicates_for_bb (basi
if (CASE_HIGH (lab) != NULL_TREE)
{
tree cmp1 = fold_build2 (GE_EXPR, boolean_type_node, idx,
- CASE_LOW (lab));
+ fold_convert (idx_type,
+ CASE_LOW (lab)));
tree cmp2 = fold_build2 (LE_EXPR, boolean_type_node, idx,
- CASE_HIGH (lab));
+ fold_convert (idx_type,
+ CASE_HIGH (lab)));
cmp = fold_build2 (BIT_AND_EXPR, boolean_type_node, cmp1, cmp2);
lab_range.set (CASE_LOW (lab), CASE_HIGH (lab));
}
else
{
cmp = fold_build2 (EQ_EXPR, boolean_type_node, idx,
- CASE_LOW (lab));
+ fold_convert (idx_type, CASE_LOW (lab)));
lab_range.set (CASE_LOW (lab));
}
--- gcc/testsuite/gcc.dg/pr105770.c.jj 2022-05-30 11:08:30.603530499 +0200
+++ gcc/testsuite/gcc.dg/pr105770.c 2022-05-30 11:07:12.066406193 +0200
@@ -0,0 +1,19 @@
+/* PR tree-optimization/105770 */
+/* { dg-do compile } */
+/* { dg-options "-O1 -funswitch-loops -fno-tree-forwprop" } */
+
+char a;
+
+void
+foo (void)
+{
+ while (a)
+ switch (a)
+ {
+ case ' ':
+ case '\t':
+ return;
+ }
+
+ __builtin_unreachable ();
+}
Jakub
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [PATCH] unswitch: Fold case label lo/hi values to index type [PR105770]
2022-05-31 9:32 [PATCH] unswitch: Fold case label lo/hi values to index type [PR105770] Jakub Jelinek
@ 2022-05-31 9:52 ` Richard Biener
0 siblings, 0 replies; 2+ messages in thread
From: Richard Biener @ 2022-05-31 9:52 UTC (permalink / raw)
To: Jakub Jelinek; +Cc: Richard Biener, gcc-patches
> Am 31.05.2022 um 11:33 schrieb Jakub Jelinek via Gcc-patches <gcc-patches@gcc.gnu.org>:
>
> Hi!
>
> The following testcase ICEs because we use different types in comparison,
> idx has int type, while CASE_LOW has char type.
>
> While I believe all CASE_{LOW,HIGH} in the same switch have to use the same
> or compatible type, the index expression can have a promoted type as happens
> in this testcase. Other spots that handle switches do such foldings too.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok.
Richard
> 2022-05-31 Jakub Jelinek <jakub@redhat.com>
>
> PR tree-optimization/105770
> * tree-ssa-loop-unswitch.cc (find_unswitching_predicates_for_bb): Cast
> CASE_LOW and CASE_HIGH to TREE_TYPE (idx) before comparisons with idx.
>
> * gcc.dg/pr105770.c: New test.
>
> --- gcc/tree-ssa-loop-unswitch.cc.jj 2022-05-25 11:07:29.754185772 +0200
> +++ gcc/tree-ssa-loop-unswitch.cc 2022-05-30 10:57:23.165131441 +0200
> @@ -494,6 +494,7 @@ find_unswitching_predicates_for_bb (basi
> {
> unsigned nlabels = gimple_switch_num_labels (stmt);
> tree idx = gimple_switch_index (stmt);
> + tree idx_type = TREE_TYPE (idx);
> if (TREE_CODE (idx) != SSA_NAME
> || nlabels < 1)
> return;
> @@ -526,16 +527,18 @@ find_unswitching_predicates_for_bb (basi
> if (CASE_HIGH (lab) != NULL_TREE)
> {
> tree cmp1 = fold_build2 (GE_EXPR, boolean_type_node, idx,
> - CASE_LOW (lab));
> + fold_convert (idx_type,
> + CASE_LOW (lab)));
> tree cmp2 = fold_build2 (LE_EXPR, boolean_type_node, idx,
> - CASE_HIGH (lab));
> + fold_convert (idx_type,
> + CASE_HIGH (lab)));
> cmp = fold_build2 (BIT_AND_EXPR, boolean_type_node, cmp1, cmp2);
> lab_range.set (CASE_LOW (lab), CASE_HIGH (lab));
> }
> else
> {
> cmp = fold_build2 (EQ_EXPR, boolean_type_node, idx,
> - CASE_LOW (lab));
> + fold_convert (idx_type, CASE_LOW (lab)));
> lab_range.set (CASE_LOW (lab));
> }
>
> --- gcc/testsuite/gcc.dg/pr105770.c.jj 2022-05-30 11:08:30.603530499 +0200
> +++ gcc/testsuite/gcc.dg/pr105770.c 2022-05-30 11:07:12.066406193 +0200
> @@ -0,0 +1,19 @@
> +/* PR tree-optimization/105770 */
> +/* { dg-do compile } */
> +/* { dg-options "-O1 -funswitch-loops -fno-tree-forwprop" } */
> +
> +char a;
> +
> +void
> +foo (void)
> +{
> + while (a)
> + switch (a)
> + {
> + case ' ':
> + case '\t':
> + return;
> + }
> +
> + __builtin_unreachable ();
> +}
>
> Jakub
>
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2022-05-31 9:32 [PATCH] unswitch: Fold case label lo/hi values to index type [PR105770] Jakub Jelinek
2022-05-31 9:52 ` Richard Biener
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