* [PATCH] if-to-switch: fix matching of negative conditions
@ 2020-12-08 13:22 Martin Liška
2020-12-08 13:35 ` Martin Liška
0 siblings, 1 reply; 2+ messages in thread
From: Martin Liška @ 2020-12-08 13:22 UTC (permalink / raw)
To: gdb-patches
We must be careful which edge we follow for conditions
of a negative form (index != 2).
Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
Ready to be installed?
Thanks,
Martin
gcc/ChangeLog:
PR tree-optimization/98182
* gimple-if-to-switch.cc (pass_if_to_switch::execute): Request
chain linkage through false edges only.
gcc/testsuite/ChangeLog:
PR tree-optimization/98182
* gcc.dg/tree-ssa/if-to-switch-10.c: New test.
* gcc.dg/tree-ssa/pr98182.c: New test.
---
gcc/gimple-if-to-switch.cc | 6 +++
.../gcc.dg/tree-ssa/if-to-switch-10.c | 44 +++++++++++++++++++
gcc/testsuite/gcc.dg/tree-ssa/pr98182.c | 18 ++++++++
3 files changed, 68 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/if-to-switch-10.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr98182.c
diff --git a/gcc/gimple-if-to-switch.cc b/gcc/gimple-if-to-switch.cc
index 8e1043ae7c4..311f6f6ac97 100644
--- a/gcc/gimple-if-to-switch.cc
+++ b/gcc/gimple-if-to-switch.cc
@@ -522,6 +522,12 @@ pass_if_to_switch::execute (function *fun)
if (!info2 || info->m_ranges[0].exp != info2->m_ranges[0].exp)
break;
+ /* It is important that the blocks are linked through FALSE_EDGE.
+ For an expression of index != VALUE, true and false edges
+ are flipped. */
+ if (info2->m_false_edge != e)
+ break;
+
chain->m_entries.safe_push (info2);
bitmap_set_bit (seen_bbs, e->src->index);
info = info2;
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/if-to-switch-10.c b/gcc/testsuite/gcc.dg/tree-ssa/if-to-switch-10.c
new file mode 100644
index 00000000000..7b8da1c9f3c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/if-to-switch-10.c
@@ -0,0 +1,44 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-iftoswitch-optimized" } */
+
+int global;
+int foo ();
+
+int main(int argc, char **argv)
+{
+ if (argc != 1)
+ {
+ if (argc != 2)
+ {
+ if (argc == 3)
+ {
+ foo ();
+ foo ();
+ }
+ else if (argc == 4)
+ {
+ foo ();
+ }
+ else if (argc == 5)
+ {
+ global = 2;
+ }
+ else
+ global -= 123;
+ }
+ else
+ {
+ global += 1;
+ }
+ }
+ else
+ foo ();
+
+
+ global -= 12;
+ return 0;
+}
+
+/* { dg-final { scan-tree-dump "Canonical GIMPLE case clusters: 1 2 3 4 5" "iftoswitch" } } */
+/* { dg-final { scan-tree-dump "Condition chain with \[^\n\r]\* BBs transformed into a switch statement." "iftoswitch" } } */
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr98182.c b/gcc/testsuite/gcc.dg/tree-ssa/pr98182.c
new file mode 100644
index 00000000000..29a547e3788
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr98182.c
@@ -0,0 +1,18 @@
+/* PR tree-optimization/98182 */
+/* { dg-do compile } */
+/* { dg-options "-O1 --param case-values-threshold=1 -fdump-tree-iftoswitch-optimized" } */
+
+int global;
+int foo ();
+
+int main(int argc, char **argv)
+{
+ if (argc != 1)
+ __builtin_abort ();
+ else if (argc != 2)
+ __builtin_abort ();
+ else
+ return 0;
+}
+
+/* { dg-final { scan-tree-dump-not "Condition chain" "iftoswitch" } } */
--
2.29.2
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] if-to-switch: fix matching of negative conditions
2020-12-08 13:22 [PATCH] if-to-switch: fix matching of negative conditions Martin Liška
@ 2020-12-08 13:35 ` Martin Liška
0 siblings, 0 replies; 2+ messages in thread
From: Martin Liška @ 2020-12-08 13:35 UTC (permalink / raw)
To: gdb-patches
Whoops, sorry, bad mailing list.
On 12/8/20 2:22 PM, Martin Liška wrote:
> We must be careful which edge we follow for conditions
> of a negative form (index != 2).
>
> Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
>
> Ready to be installed?
> Thanks,
> Martin
>
> gcc/ChangeLog:
>
> PR tree-optimization/98182
> * gimple-if-to-switch.cc (pass_if_to_switch::execute): Request
> chain linkage through false edges only.
>
> gcc/testsuite/ChangeLog:
>
> PR tree-optimization/98182
> * gcc.dg/tree-ssa/if-to-switch-10.c: New test.
> * gcc.dg/tree-ssa/pr98182.c: New test.
> ---
> gcc/gimple-if-to-switch.cc | 6 +++
> .../gcc.dg/tree-ssa/if-to-switch-10.c | 44 +++++++++++++++++++
> gcc/testsuite/gcc.dg/tree-ssa/pr98182.c | 18 ++++++++
> 3 files changed, 68 insertions(+)
> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/if-to-switch-10.c
> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr98182.c
>
> diff --git a/gcc/gimple-if-to-switch.cc b/gcc/gimple-if-to-switch.cc
> index 8e1043ae7c4..311f6f6ac97 100644
> --- a/gcc/gimple-if-to-switch.cc
> +++ b/gcc/gimple-if-to-switch.cc
> @@ -522,6 +522,12 @@ pass_if_to_switch::execute (function *fun)
> if (!info2 || info->m_ranges[0].exp != info2->m_ranges[0].exp)
> break;
>
> + /* It is important that the blocks are linked through FALSE_EDGE.
> + For an expression of index != VALUE, true and false edges
> + are flipped. */
> + if (info2->m_false_edge != e)
> + break;
> +
> chain->m_entries.safe_push (info2);
> bitmap_set_bit (seen_bbs, e->src->index);
> info = info2;
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/if-to-switch-10.c b/gcc/testsuite/gcc.dg/tree-ssa/if-to-switch-10.c
> new file mode 100644
> index 00000000000..7b8da1c9f3c
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/if-to-switch-10.c
> @@ -0,0 +1,44 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-iftoswitch-optimized" } */
> +
> +int global;
> +int foo ();
> +
> +int main(int argc, char **argv)
> +{
> + if (argc != 1)
> + {
> + if (argc != 2)
> + {
> + if (argc == 3)
> + {
> + foo ();
> + foo ();
> + }
> + else if (argc == 4)
> + {
> + foo ();
> + }
> + else if (argc == 5)
> + {
> + global = 2;
> + }
> + else
> + global -= 123;
> + }
> + else
> + {
> + global += 1;
> + }
> + }
> + else
> + foo ();
> +
> +
> + global -= 12;
> + return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump "Canonical GIMPLE case clusters: 1 2 3 4 5" "iftoswitch" } } */
> +/* { dg-final { scan-tree-dump "Condition chain with \[^\n\r]\* BBs transformed into a switch statement." "iftoswitch" } } */
> +
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr98182.c b/gcc/testsuite/gcc.dg/tree-ssa/pr98182.c
> new file mode 100644
> index 00000000000..29a547e3788
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr98182.c
> @@ -0,0 +1,18 @@
> +/* PR tree-optimization/98182 */
> +/* { dg-do compile } */
> +/* { dg-options "-O1 --param case-values-threshold=1 -fdump-tree-iftoswitch-optimized" } */
> +
> +int global;
> +int foo ();
> +
> +int main(int argc, char **argv)
> +{
> + if (argc != 1)
> + __builtin_abort ();
> + else if (argc != 2)
> + __builtin_abort ();
> + else
> + return 0;
> +}
> +
> +/* { dg-final { scan-tree-dump-not "Condition chain" "iftoswitch" } } */
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