On Fri, Feb 16, 2018 at 6:18 PM, <vladimir.mezent...@oracle.com> wrote:
> From: Vladimir Mezentsev <vladimir.mezent...@oracle.com>
>
> Ramana Radhakrishnan made a workaround in gcc/config/aarch64/aarch64.c to
> resolve
> bootstrap comparison failure (2015-11-10, commit
> bc443a71dafa2e707bae4b2fa74f83b05dea37ab).
> The real bug is in gcc/varasm.c.
> hash_section() returns an unstable value.
> As result, two blocks are created in get_block_for_section() for one unnamed
> section.
> A list of objects in these blocks depends on the -gtoggle option.
> I removed Ramana's workaround in gcc/config/aarch64/aarch64.c and
> I fixed hash_section() in gcc/varasm.c
>
> Bootstrapped on aarch64-unknown-linux-gnu including (c,c++ and go).
> Testing finished ok.
Ok.
Thanks,
Richard.
> ChangeLog:
> 2018-02-15 Vladimir Mezentsev <vladimir.mezent...@oracle.com>
>
> PR gcc/68256
> * varasm.c (hash_section): Return an unchangeble hash value
> * config/aarch64/aarch64.c (aarch64_use_blocks_for_constant_p):
> Return !aarch64_can_use_per_function_literal_pools_p ();
> ---
> gcc/config/aarch64/aarch64.c | 8 +++-----
> gcc/varasm.c | 2 +-
> 2 files changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index 174310c..a0a495d 100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -7596,11 +7596,9 @@ aarch64_can_use_per_function_literal_pools_p (void)
> static bool
> aarch64_use_blocks_for_constant_p (machine_mode, const_rtx)
> {
> - /* Fixme:: In an ideal world this would work similar
> - to the logic in aarch64_select_rtx_section but this
> - breaks bootstrap in gcc go. For now we workaround
> - this by returning false here. */
> - return false;
> + /* We can't use blocks for constants when we're using a per-function
> + constant pool. */
> + return !aarch64_can_use_per_function_literal_pools_p ();
> }
>
> /* Select appropriate section for constants depending
> diff --git a/gcc/varasm.c b/gcc/varasm.c
> index b045efa..5aae5b4 100644
> --- a/gcc/varasm.c
> +++ b/gcc/varasm.c
> @@ -225,7 +225,7 @@ hash_section (section *sect)
> {
> if (sect->common.flags & SECTION_NAMED)
> return htab_hash_string (sect->named.name);
> - return sect->common.flags;
> + return sect->common.flags & ~SECTION_DECLARED;
> }
>
> /* Helper routines for maintaining object_block_htab. */
> --
> 1.8.3.1
>
