Re: [PATCH] IRA: Make sure array is big enough

[Vladimir Makarov <vmakarov@redhat.com>]

On 2022-10-25 06:01, Torbjörn SVENSSON wrote:
> In commit 081c96621da, the call to resize_reg_info() was moved before
> the call to remove_scratches() and the latter one can increase the
> number of regs and that would cause an out of bounds usage on the
> reg_renumber global array.
>
> Without this patch, the following testcase randomly fails with:
> during RTL pass: ira
> In file included from /src/gcc/testsuite/gcc.dg/compat//struct-by-value-5b_y.c:13:
> /src/gcc/testsuite/gcc.dg/compat//struct-by-value-5b_y.c: In function 'checkgSf13':
> /src/gcc/testsuite/gcc.dg/compat//fp-struct-test-by-value-y.h:28:1: internal compiler error: Segmentation fault
> /src/gcc/testsuite/gcc.dg/compat//struct-by-value-5b_y.c:22:1: note: in expansion of macro 'TEST'
>
> gcc/ChangeLog:
>
> 	* ira.c: Resize array after reg number increased.

The patch is ok to commit it into gcc-11,12 branches and master.

Thank you for fixing this.

> Co-Authored-By: Yvan ROUX <yvan.roux@foss.st.com>
> Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com>
> ---
>   gcc/ira.cc | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/gcc/ira.cc b/gcc/ira.cc
> index 42c9cead9f8..d28a67b2546 100644
> --- a/gcc/ira.cc
> +++ b/gcc/ira.cc
> @@ -5718,6 +5718,7 @@ ira (FILE *f)
>       regstat_free_ri ();
>       regstat_init_n_sets_and_refs ();
>       regstat_compute_ri ();
> +    resize_reg_info ();
>     };
>   
>     int max_regno_before_rm = max_reg_num ();