Re: [PATCH, PR66652] Use max_loop_iterations in transform_to_exit_first_loop_alt
On 29/06/15 19:58, Jeff Law wrote:
On 06/29/2015 08:24 AM, Tom de Vries wrote:
Hi,
this patch fixes PR66652.
It uses max_loop_iterations in transform_to_exit_first_loop_alt to
ensure that the new loop bound nit + 1 doesn't overflow.
Bootstrapped and reg-tested on x86_64.
OK for trunk?
Thanks,
- Tom
0001-Use-max_loop_iterations-in-transform_to_exit_first_l.patch
Use max_loop_iterations in transform_to_exit_first_loop_alt
2015-06-29 Tom de Vriest...@codesourcery.com
PR tree-optimization/66652
* tree-parloops.c (try_transform_to_exit_first_loop_alt): Use
max_loop_iterations to determine if nit + 1 overflows.
* testsuite/libgomp.c/parloops-exit-first-loop-alt-3.c (f): Rewrite
using restrict pointers.
(main): Add arguments to calls to f.
* testsuite/libgomp.c/parloops-exit-first-loop-alt.c: Same.
* gcc.dg/parloops-exit-first-loop-alt-pr66652.c: New test.
* gcc.dg/parloops-exit-first-loop-alt-3.c (f): Rewrite using
restrict
pointers.
* gcc.dg/parloops-exit-first-loop-alt.c: Same.
OK.
Make sure to put the PR marker in the testsuite/ChangeLog entry
True, I abbreviate it in the log, but my commit script (
https://github.com/vries/bin-scripts/blob/master/git-prepare-gnu-commit.sh
) applies the PR line to all the ChangeLog hunks.
and drop
the testsuite/ prefix in the testsuite/ChangeLog entry.
The testsuite/ prefix is used because the it's for the ChangeLog in dir
libgomp.
Committed as attached:
- fixed typo in comment
- updated test-case modifications to be applicable on trunk (given that
there's no approval yet for the fix for PR66642, see
https://gcc.gnu.org/ml/gcc-patches/2015-06/msg01768.html)
- included ChangeLog file changes, given the ChangeLog questions.
Thanks,
- Tom
Use max_loop_iterations in transform_to_exit_first_loop_alt
2015-06-30 Tom de Vries t...@codesourcery.com
PR tree-optimization/66652
* tree-parloops.c (try_transform_to_exit_first_loop_alt): Use
max_loop_iterations to determine if nit + 1 overflows.
* testsuite/libgomp.c/parloops-exit-first-loop-alt-3.c (f): Rewrite
using restrict pointers.
(main): Add arguments to calls to f.
* testsuite/libgomp.c/parloops-exit-first-loop-alt.c: Same.
* gcc.dg/parloops-exit-first-loop-alt-pr66652.c: New test.
* gcc.dg/parloops-exit-first-loop-alt-3.c (f): Rewrite using restrict
pointers.
* gcc.dg/parloops-exit-first-loop-alt.c: Same.
---
gcc/ChangeLog | 6 +
gcc/testsuite/ChangeLog| 8 ++
.../gcc.dg/parloops-exit-first-loop-alt-3.c| 2 +-
.../gcc.dg/parloops-exit-first-loop-alt-pr66652.c | 31 ++
.../gcc.dg/parloops-exit-first-loop-alt.c | 19 +
gcc/tree-parloops.c| 31 ++
libgomp/ChangeLog | 8 ++
.../libgomp.c/parloops-exit-first-loop-alt-3.c | 4 +--
.../libgomp.c/parloops-exit-first-loop-alt.c | 5 ++--
9 files changed, 97 insertions(+), 17 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-pr66652.c
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 96f4f8d..1940d04 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2015-06-30 Tom de Vries t...@codesourcery.com
+
+ PR tree-optimization/66652
+ * tree-parloops.c (try_transform_to_exit_first_loop_alt): Use
+ max_loop_iterations to determine if nit + 1 overflows.
+
2015-06-30 Bin Cheng bin.ch...@arm.com
* tree-ssa-loop-ivopts.c (record_sub_use): Don't reset ssa_name
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 9c2f20b..f249a7d 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2015-06-30 Tom de Vries t...@codesourcery.com
+
+ PR tree-optimization/66652
+ * gcc.dg/parloops-exit-first-loop-alt-pr66652.c: New test.
+ * gcc.dg/parloops-exit-first-loop-alt-3.c (f): Rewrite using restrict
+ pointers.
+ * gcc.dg/parloops-exit-first-loop-alt.c: Same.
+
2015-06-29 Paolo Carlini paolo.carl...@oracle.com
PR c++/65977
diff --git a/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-3.c b/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-3.c
index b0fde37..fec53a1 100644
--- a/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-3.c
+++ b/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-3.c
@@ -7,7 +7,7 @@
unsigned int *a;
unsigned int
-f (unsigned int n)
+f (unsigned int n, unsigned int *__restrict__ a)
{
int i;
unsigned int sum = 1;
diff --git a/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-pr66652.c b/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-pr66652.c
new file mode 100644
index 000..2ea097d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-pr66652.c
@@ -0,0 +1,31 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target pthread } */
+/* { dg-options -O2 -ftree-parallelize-loops=2 -fdump-tree-parloops } */
+
+#include stdio.h
[PATCH, PR66652] Use max_loop_iterations in transform_to_exit_first_loop_alt
Hi,
this patch fixes PR66652.
It uses max_loop_iterations in transform_to_exit_first_loop_alt to
ensure that the new loop bound nit + 1 doesn't overflow.
Bootstrapped and reg-tested on x86_64.
OK for trunk?
Thanks,
- Tom
Use max_loop_iterations in transform_to_exit_first_loop_alt
2015-06-29 Tom de Vries t...@codesourcery.com
PR tree-optimization/66652
* tree-parloops.c (try_transform_to_exit_first_loop_alt): Use
max_loop_iterations to determine if nit + 1 overflows.
* testsuite/libgomp.c/parloops-exit-first-loop-alt-3.c (f): Rewrite
using restrict pointers.
(main): Add arguments to calls to f.
* testsuite/libgomp.c/parloops-exit-first-loop-alt.c: Same.
* gcc.dg/parloops-exit-first-loop-alt-pr66652.c: New test.
* gcc.dg/parloops-exit-first-loop-alt-3.c (f): Rewrite using restrict
pointers.
* gcc.dg/parloops-exit-first-loop-alt.c: Same.
---
.../gcc.dg/parloops-exit-first-loop-alt-3.c| 2 +-
.../gcc.dg/parloops-exit-first-loop-alt-pr66652.c | 31 ++
.../gcc.dg/parloops-exit-first-loop-alt.c | 19 +
gcc/tree-parloops.c| 31 ++
.../libgomp.c/parloops-exit-first-loop-alt-3.c | 6 ++---
.../libgomp.c/parloops-exit-first-loop-alt.c | 7 ++---
6 files changed, 77 insertions(+), 19 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-pr66652.c
diff --git a/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-3.c b/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-3.c
index b0fde37..fec53a1 100644
--- a/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-3.c
+++ b/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-3.c
@@ -7,7 +7,7 @@
unsigned int *a;
unsigned int
-f (unsigned int n)
+f (unsigned int n, unsigned int *__restrict__ a)
{
int i;
unsigned int sum = 1;
diff --git a/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-pr66652.c b/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-pr66652.c
new file mode 100644
index 000..2ea097d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt-pr66652.c
@@ -0,0 +1,31 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target pthread } */
+/* { dg-options -O2 -ftree-parallelize-loops=2 -fdump-tree-parloops } */
+
+#include stdio.h
+#include stdlib.h
+#include limits.h
+
+unsigned int
+f (unsigned int n, unsigned int sum)
+{
+ unsigned int i;
+
+ i = UINT_MAX;
+ do
+{
+ sum += i % 13;
+ i++;
+}
+ while (i n - 1);
+
+ return sum;
+}
+
+/* Four times % 13:
+ - once in f._loopfn.0
+ - once in the parallel
+ - once in the low iteration count loop
+ - once for a peeled off last iteration following the parallel.
+ In other words, we want try_transform_to_exit_first_loop_alt to fail. */
+/* { dg-final { scan-tree-dump-times (?n)% 13 4 parloops } } */
diff --git a/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt.c b/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt.c
index b36f01b..e088fa1 100644
--- a/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt.c
+++ b/gcc/testsuite/gcc.dg/parloops-exit-first-loop-alt.c
@@ -4,14 +4,9 @@
/* Variable bound, vector addition. */
-#define N 1000
-
-unsigned int a[N];
-unsigned int b[N];
-unsigned int c[N];
-
void
-f (unsigned int n)
+f (unsigned int n, unsigned int *__restrict__ a, unsigned int *__restrict__ b,
+ unsigned int *__restrict__ c)
{
int i;
@@ -19,9 +14,9 @@ f (unsigned int n)
c[i] = a[i] + b[i];
}
-/* Three times three array accesses:
- - three in f._loopfn.0
- - three in the parallel
- - three in the low iteration count loop
+/* Three times a store:
+ - one in f._loopfn.0
+ - one in the parallel
+ - one in the low iteration count loop
Crucially, none for a peeled off last iteration following the parallel. */
-/* { dg-final { scan-tree-dump-times (?n)\\\[i 9 parloops } } */
+/* { dg-final { scan-tree-dump-times (?n)^ \\*_\[0-9\]* 3 parloops } } */
diff --git a/gcc/tree-parloops.c b/gcc/tree-parloops.c
index cb0ba54..32d059a 100644
--- a/gcc/tree-parloops.c
+++ b/gcc/tree-parloops.c
@@ -1795,8 +1795,39 @@ try_transform_to_exit_first_loop_alt (struct loop *loop,
gcc_assert (TREE_CODE (nit) == SSA_NAME);
+ /* Variable nit is the loop bound as returned by canonicalize_loop_ivs, for an
+ iv with base 0 and step 1 that is incremented in the latch, like this:
+
+ bb header:
+ # iv_1 = PHI 0 (preheader), iv_2 (latch)
+ ...
+ if (iv_1 nit)
+ goto bb latch;
+ else
+ goto bb exit;
+
+ bb latch:
+ iv_2 = ivtmp_1 + 1;
+ goto bb header;
+
+ The range of iv_1 is [0, nit]. The latch edge is taken for
+ iv_1 == [0, nit - 1] and the exit edge is taken for iv_1 == nit. So the
+ number of latch executions is equal to nit.
+
+ The function max_loop_iterations gives us the maximum number of latch
+ executions, so it gives us the maximum value of nit. */
+ widest_int nit_max;
+ if (!max_loop_iterations
Re: [PATCH, PR66652] Use max_loop_iterations in transform_to_exit_first_loop_alt
On 06/29/2015 08:24 AM, Tom de Vries wrote: Hi, this patch fixes PR66652. It uses max_loop_iterations in transform_to_exit_first_loop_alt to ensure that the new loop bound nit + 1 doesn't overflow. Bootstrapped and reg-tested on x86_64. OK for trunk? Thanks, - Tom 0001-Use-max_loop_iterations-in-transform_to_exit_first_l.patch Use max_loop_iterations in transform_to_exit_first_loop_alt 2015-06-29 Tom de Vriest...@codesourcery.com PR tree-optimization/66652 * tree-parloops.c (try_transform_to_exit_first_loop_alt): Use max_loop_iterations to determine if nit + 1 overflows. * testsuite/libgomp.c/parloops-exit-first-loop-alt-3.c (f): Rewrite using restrict pointers. (main): Add arguments to calls to f. * testsuite/libgomp.c/parloops-exit-first-loop-alt.c: Same. * gcc.dg/parloops-exit-first-loop-alt-pr66652.c: New test. * gcc.dg/parloops-exit-first-loop-alt-3.c (f): Rewrite using restrict pointers. * gcc.dg/parloops-exit-first-loop-alt.c: Same. OK. Make sure to put the PR marker in the testsuite/ChangeLog entry and drop the testsuite/ prefix in the testsuite/ChangeLog entry. jeff
