On Thu, Nov 13, 2014 at 12:51:05PM -0800, Teresa Johnson wrote:
> On Thu, Nov 13, 2014 at 7:39 AM, Teresa Johnson <tejohn...@google.com> wrote:
> > On Thu, Nov 13, 2014 at 7:12 AM, Jakub Jelinek <ja...@redhat.com> wrote:
> >> And for release branches I'd really prefer tree-ssa-strlen.c change.
> >
> > Ok, I started testing the initializer_zerop change on the 4_9 branch,
> > will also test the strlen fix and send that patch for review here when
> > it completes.
>
> Here is the more conservative patch for 4_9. Bootstrapped and tested
> on x86_64-unknown-linux-gnu. Ok for gcc-4_9 branch?
Ok, thanks. But I have a comment regarding the test below:
> 2014-11-13 Teresa Johnson <tejohn...@google.com>
>
> gcc:
> PR tree-optimization/63841
> * tree-ssa-strlen.c (strlen_optimize_stmt): Ignore clobbers.
>
> 2014-11-13 Teresa Johnson <tejohn...@google.com>
>
> gcc/testsuite:
> PR tree-optimization/63841
> * testsuite/g++.dg/tree-ssa/pr63841.C: New test.
>
> Index: tree-ssa-strlen.c
> ===================================================================
> --- tree-ssa-strlen.c (revision 217503)
> +++ tree-ssa-strlen.c (working copy)
> @@ -1856,7 +1856,7 @@ strlen_optimize_stmt (gimple_stmt_iterator *gsi)
> break;
> }
> }
> - else if (is_gimple_assign (stmt))
> + else if (is_gimple_assign (stmt) && !gimple_clobber_p (stmt))
> {
> tree lhs = gimple_assign_lhs (stmt);
>
> Index: testsuite/g++.dg/tree-ssa/pr63841.C
> ===================================================================
> --- testsuite/g++.dg/tree-ssa/pr63841.C (revision 0)
> +++ testsuite/g++.dg/tree-ssa/pr63841.C (working copy)
> @@ -0,0 +1,38 @@
> +/* { dg-do run } */
> +/* { dg-options "-O2" } */
> +
> +#include <cstdio>
> +#include <string>
> +
> +std::string __attribute__ ((noinline)) comp_test_write() {
> + std::string data;
> +
> + for (int i = 0; i < 2; ++i) {
> + char b = 1 >> (i * 8);
> + data.append(&b, 1);
> + }
> +
> + return data;
> +}
> +
> +std::string __attribute__ ((noinline)) comp_test_write_good() {
> + std::string data;
> +
> + char b;
> + for (int i = 0; i < 2; ++i) {
> + b = 1 >> (i * 8);
> + data.append(&b, 1);
> + }
> +
> + return data;
> +}
> +
> +int main() {
> + std::string good = comp_test_write_good();
> + printf("expected: %hx\n", *(short*)good.c_str());
> +
> + std::string bad = comp_test_write();
> + printf("got: %hx\n", *(short*)bad.c_str());
Supposedly the printfs should have been removed and the #include <cstdio>
isn't needed then either. No need to clutter the test output and log files.
On the other side, tests should abort (); or __builtin_abort (); on failure,
not just return non-zero.
> +
> + return good != bad;
> +}
Jakub
