Hello.
I've just followed Richi's advises in the PR.
Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
Ready to be installed?
Martin
>From 9a850909d00e2b63961167665d48f7ebbb99ac84 Mon Sep 17 00:00:00 2001
From: marxin <mli...@suse.cz>
Date: Thu, 2 Mar 2017 13:34:55 +0100
Subject: [PATCH] Add -Wdisabled-optimization to loop prefetching pass (PR
tree-optimization/79803).
gcc/ChangeLog:
2017-03-02 Martin Liska <mli...@suse.cz>
PR tree-optimization/79803
* tree-ssa-loop-prefetch.c (tree_ssa_prefetch_arrays): Remove
assert.
(pass_loop_prefetch::execute): Disabled optimization if an
assumption about L1 cache size is not met.
gcc/testsuite/ChangeLog:
2017-03-02 Martin Liska <mli...@suse.cz>
PR tree-optimization/79803
* gcc.dg/tree-ssa/pr79803.c: New test.
---
gcc/testsuite/gcc.dg/tree-ssa/pr79803.c | 39 +++++++++++++++++++++++++++++++++
gcc/tree-ssa-loop-prefetch.c | 13 +++++++----
2 files changed, 48 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr79803.c
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr79803.c b/gcc/testsuite/gcc.dg/tree-ssa/pr79803.c
new file mode 100644
index 00000000000..e43a40739d5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr79803.c
@@ -0,0 +1,39 @@
+/* { dg-do compile { target { x86_64-*-* } } } */
+/* { dg-options "-march=opteron-sse3 -Ofast --param l1-cache-line-size=3 -Wdisabled-optimization" } */
+/* { dg-require-effective-target indirect_jumps } */
+
+#include <setjmp.h>
+
+extern void abort (void);
+
+jmp_buf buf;
+
+void raise0(void)
+{
+ __builtin_longjmp (buf, 1);
+}
+
+int execute(int cmd) /* { dg-warning "'l1-cache-size' is not an even number 3" } */
+{
+ int last = 0;
+
+ if (__builtin_setjmp (buf) == 0)
+ while (1)
+ {
+ last = 1;
+ raise0 ();
+ }
+
+ if (last == 0)
+ return 0;
+ else
+ return cmd;
+}
+
+int main(void)
+{
+ if (execute (1) == 0)
+ abort ();
+
+ return 0;
+}
diff --git a/gcc/tree-ssa-loop-prefetch.c b/gcc/tree-ssa-loop-prefetch.c
index 54cd9421998..2cdf210308b 100644
--- a/gcc/tree-ssa-loop-prefetch.c
+++ b/gcc/tree-ssa-loop-prefetch.c
@@ -47,6 +47,7 @@ along with GCC; see the file COPYING3. If not see
#include "langhooks.h"
#include "tree-inline.h"
#include "tree-data-ref.h"
+#include "diagnostic-core.h"
/* This pass inserts prefetch instructions to optimize cache usage during
accesses to arrays in loops. It processes loops sequentially and:
@@ -1977,10 +1978,6 @@ tree_ssa_prefetch_arrays (void)
set_builtin_decl (BUILT_IN_PREFETCH, decl, false);
}
- /* We assume that size of cache line is a power of two, so verify this
- here. */
- gcc_assert ((PREFETCH_BLOCK & (PREFETCH_BLOCK - 1)) == 0);
-
FOR_EACH_LOOP (loop, LI_FROM_INNERMOST)
{
if (dump_file && (dump_flags & TDF_DETAILS))
@@ -2038,6 +2035,14 @@ pass_loop_prefetch::execute (function *fun)
if (number_of_loops (fun) <= 1)
return 0;
+ if ((PREFETCH_BLOCK & (PREFETCH_BLOCK - 1)) != 0)
+ {
+ warning (OPT_Wdisabled_optimization,
+ "%<l1-cache-size%> is not an even number %d",
+ PREFETCH_BLOCK);
+ return 0;
+ }
+
return tree_ssa_prefetch_arrays ();
}
--
2.11.1
