On Sat, 25 Nov 2017, Jakub Jelinek wrote:
> Hi!
>
> As the testcases show, it is essential that bss_initializer_p returns
> true for DECL_COMMON vars without initializer, even when they are
> TREE_READONLY, otherwise they aren't really common, e.g.
> if (DECL_COMMON (decl))
> {
> /* If the decl has been given an explicit section name, or it resides
> in a non-generic address space, then it isn't common, and shouldn't
> be handled as such. */
> gcc_assert (DECL_SECTION_NAME (decl) == NULL
> && ADDR_SPACE_GENERIC_P (as));
> if (DECL_THREAD_LOCAL_P (decl))
> return tls_comm_section;
> else if (TREE_PUBLIC (decl) && bss_initializer_p (decl))
> return comm_section;
> }
> falls through into non-common code, and on section anchors target sometimes
> ICE.
>
> Fixed thusly, bootstrapped/regtested on powerpc64le-linux, bootstrapped
> also on {powerpc64,x86_64,i686}-linux, ok for trunk if the pending
> regtests on the above 3 targets succeed?
Ok.
Richard.
> 2017-11-24 Jakub Jelinek <ja...@redhat.com>
>
> PR target/83100
> * varasm.c (bss_initializer_p): Return true for DECL_COMMON
> TREE_READONLY decls.
>
> * gcc.dg/pr83100-1.c: New test.
> * gcc.dg/pr83100-2.c: New test.
> * gcc.dg/pr83100-3.c: New test.
> * gcc.dg/pr83100-4.c: New test.
>
> --- gcc/varasm.c.jj 2017-11-21 20:23:02.000000000 +0100
> +++ gcc/varasm.c 2017-11-24 21:43:55.616951823 +0100
> @@ -986,9 +986,9 @@ decode_reg_name (const char *name)
> bool
> bss_initializer_p (const_tree decl)
> {
> - /* Do not put constants into the .bss section, they belong in a readonly
> - section. */
> - return (!TREE_READONLY (decl)
> + /* Do not put non-common constants into the .bss section, they belong in
> + a readonly section. */
> + return ((!TREE_READONLY (decl) || DECL_COMMON (decl))
> && (DECL_INITIAL (decl) == NULL
> /* In LTO we have no errors in program; error_mark_node is used
> to mark offlined constructors. */
> --- gcc/testsuite/gcc.dg/pr83100-1.c.jj 2017-11-24 21:56:52.957497438
> +0100
> +++ gcc/testsuite/gcc.dg/pr83100-1.c 2017-11-24 22:01:03.433437167 +0100
> @@ -0,0 +1,7 @@
> +/* PR target/83100 */
> +/* { dg-do compile { target *-*-linux* *-*-gnu* } } */
> +/* { dg-options "-O2 -fcommon -fdata-sections" } */
> +
> +const int a;
> +
> +/* { dg-final { scan-assembler "comm" } } */
> --- gcc/testsuite/gcc.dg/pr83100-2.c.jj 2017-11-24 21:58:54.475012758
> +0100
> +++ gcc/testsuite/gcc.dg/pr83100-2.c 2017-11-24 22:01:09.108367832 +0100
> @@ -0,0 +1,15 @@
> +/* PR target/83100 */
> +/* { dg-do run } */
> +/* { dg-options "-O2 -fcommon -fdata-sections" } */
> +/* { dg-additional-sources pr83100-3.c } */
> +/* { dg-skip-if "-fdata-sections not supported" { hppa*-*-hpux* nvptx-*-* }
> } */
> +
> +const int a;
> +
> +int
> +main ()
> +{
> + if (a != 7)
> + __builtin_abort ();
> + return 0;
> +}
> --- gcc/testsuite/gcc.dg/pr83100-3.c.jj 2017-11-24 21:59:57.072247956
> +0100
> +++ gcc/testsuite/gcc.dg/pr83100-3.c 2017-11-24 22:01:14.344303860 +0100
> @@ -0,0 +1,6 @@
> +/* PR target/83100 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fcommon -fdata-sections" } */
> +/* { dg-skip-if "-fdata-sections not supported" { hppa*-*-hpux* nvptx-*-* }
> } */
> +
> +const int a = 7;
> --- gcc/testsuite/gcc.dg/pr83100-4.c.jj 2017-11-24 22:00:13.405048405
> +0100
> +++ gcc/testsuite/gcc.dg/pr83100-4.c 2017-11-24 22:01:20.281231323 +0100
> @@ -0,0 +1,7 @@
> +/* PR target/83100 */
> +/* { dg-do compile { target *-*-linux* *-*-gnu* } } */
> +/* { dg-options "-O2 -fno-common -fdata-sections" } */
> +
> +const int a;
> +
> +/* { dg-final { scan-assembler "rodata.a" } } */
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
