This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH] Fix expansion with COMPOUND_LITERAL_EXPR (PR middle-end/64067)


On Wed, 26 Nov 2014, Jakub Jelinek wrote:

> Hi!
> 
> The testcase shows that when expanding ARRAY_REF from a const static var
> with initializer that contains COMPOUND_LITERAL_EXPR, we can try to expand
> COMPOUND_LITERAL_EXPR even when modifier is not EXPAND_INITIALIZER (it is
> EXPAND_SUM in that testcase, but could be many others).
> While gimplification should get rid of all the compound literal exprs
> for automatic compound literals, COMPOUND_LITERAL_EXPR for static compound
> literals can survive in the initializers, thus this patch handles them
> always.
> 
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

Ok.  (I wonder if the fallthru still makes sense or if we should
hit a gcc_unreachable () for other uses of COMPOUND_LITERAL_EXPR).

Thanks,
Richard.

> 2014-11-26  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR middle-end/64067
> 	* expr.c (expand_expr_addr_expr_1) <case COMPOUND_LITERAL_EXPR>:
> 	Handle it by returning address of COMPOUND_LITERAL_EXPR_DECL
> 	not only if modifier is EXPAND_INITIALIZER, but whenever
> 	COMPOUND_LITERAL_EXPR_DECL is non-NULL and TREE_STATIC.
> 
> 	* gcc.c-torture/compile/pr64067.c: New test.
> 
> --- gcc/expr.c.jj	2014-11-18 08:26:45.000000000 +0100
> +++ gcc/expr.c	2014-11-26 17:38:52.877675088 +0100
> @@ -7677,11 +7677,13 @@ expand_expr_addr_expr_1 (tree exp, rtx t
>        break;
>  
>      case COMPOUND_LITERAL_EXPR:
> -      /* Allow COMPOUND_LITERAL_EXPR in initializers, if e.g.
> -	 rtl_for_decl_init is called on DECL_INITIAL with
> -	 COMPOUNT_LITERAL_EXPRs in it, they aren't gimplified.  */
> -      if (modifier == EXPAND_INITIALIZER
> -	  && COMPOUND_LITERAL_EXPR_DECL (exp))
> +      /* Allow COMPOUND_LITERAL_EXPR in initializers or coming from
> +	 initializers, if e.g. rtl_for_decl_init is called on DECL_INITIAL
> +	 with COMPOUND_LITERAL_EXPRs in it, or ARRAY_REF on a const static
> +	 array with address of COMPOUND_LITERAL_EXPR in DECL_INITIAL;
> +	 the initializers aren't gimplified.  */
> +      if (COMPOUND_LITERAL_EXPR_DECL (exp)
> +	  && TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (exp)))
>  	return expand_expr_addr_expr_1 (COMPOUND_LITERAL_EXPR_DECL (exp),
>  					target, tmode, modifier, as);
>        /* FALLTHRU */
> --- gcc/testsuite/gcc.c-torture/compile/pr64067.c.jj	2014-11-26 17:37:37.835865797 +0100
> +++ gcc/testsuite/gcc.c-torture/compile/pr64067.c	2014-11-26 17:37:02.000000000 +0100
> @@ -0,0 +1,10 @@
> +/* PR middle-end/64067 */
> +
> +struct S { int s; };
> +int *const v[1] = { &((struct S) { .s = 42 }).s };
> +
> +int *
> +foo (void)
> +{
> +  return v[0];
> +}
> 
> 	Jakub
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Jeff Hawn, Jennifer Guild, Felix Imendoerffer, HRB 21284
(AG Nuernberg)
Maxfeldstrasse 5, 90409 Nuernberg, Germany


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]