Re: [PATCH] refactor gimple asm memory clobber checking

[Richard Guenther <richard dot guenther at gmail dot com>]

On Fri, Apr 15, 2011 at 3:20 PM, Nathan Froyd <froydnj@codesourcery.com> wrote:
> There are a couple places that check GIMPLE_ASMs for clobbering memory;
> this patch centralizes the logic in gimple.c.
>
> Tested on x86_64-unknown-linux-gnu. ?OK to commit?

Ok.

Thanks,
Richard.

> -Nathan
>
> ? ? ? ?* gimple.h (gimple_asm_clobbers_memory_p): Declare.
> ? ? ? ?* gimple.c (gimple_asm_clobbers_memory_p): Define.
> ? ? ? ?* ipa-pure-const.c (check_stmt): Call it.
> ? ? ? ?* tree-ssa-operands.c (get_asm_expr_operands): Likewise.
>
> diff --git a/gcc/gimple.c b/gcc/gimple.c
> index 090fc94..5dc62ea 100644
> --- a/gcc/gimple.c
> +++ b/gcc/gimple.c
> @@ -5142,4 +5142,21 @@ gimple_call_builtin_p (gimple stmt, enum built_in_function code)
> ? ? ? ? ?&& DECL_FUNCTION_CODE (fndecl) == code);
> ?}
>
> +/* Return true if STMT clobbers memory. ?STMT is required to be a
> + ? GIMPLE_ASM. ?*/
> +
> +bool
> +gimple_asm_clobbers_memory_p (const_gimple stmt)
> +{
> + ?unsigned i;
> +
> + ?for (i = 0; i < gimple_asm_nclobbers (stmt); i++)
> + ? ?{
> + ? ? ?tree op = gimple_asm_clobber_op (stmt, i);
> + ? ? ?if (strcmp (TREE_STRING_POINTER (TREE_VALUE (op)), "memory") == 0)
> + ? ? ? return true;
> + ? ?}
> +
> + ?return false;
> +}
> ?#include "gt-gimple.h"
> diff --git a/gcc/gimple.h b/gcc/gimple.h
> index 572cabc..840e149 100644
> --- a/gcc/gimple.h
> +++ b/gcc/gimple.h
> @@ -973,6 +973,7 @@ extern bool walk_stmt_load_store_ops (gimple, void *,
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?bool (*)(gimple, tree, void *));
> ?extern bool gimple_ior_addresses_taken (bitmap, gimple);
> ?extern bool gimple_call_builtin_p (gimple, enum built_in_function);
> +extern bool gimple_asm_clobbers_memory_p (const_gimple);
>
> ?/* In gimplify.c ?*/
> ?extern tree create_tmp_var_raw (tree, const char *);
> diff --git a/gcc/ipa-pure-const.c b/gcc/ipa-pure-const.c
> index b7deb57..eb5b0f6 100644
> --- a/gcc/ipa-pure-const.c
> +++ b/gcc/ipa-pure-const.c
> @@ -639,7 +639,6 @@ static void
> ?check_stmt (gimple_stmt_iterator *gsip, funct_state local, bool ipa)
> ?{
> ? gimple stmt = gsi_stmt (*gsip);
> - ?unsigned int i = 0;
>
> ? if (is_gimple_debug (stmt))
> ? ? return;
> @@ -693,16 +692,12 @@ check_stmt (gimple_stmt_iterator *gsip, funct_state local, bool ipa)
> ? ? ? ?}
> ? ? ? break;
> ? ? case GIMPLE_ASM:
> - ? ? ?for (i = 0; i < gimple_asm_nclobbers (stmt); i++)
> + ? ? ?if (gimple_asm_clobbers_memory_p (stmt))
> ? ? ? ?{
> - ? ? ? ? tree op = gimple_asm_clobber_op (stmt, i);
> - ? ? ? ? if (strcmp (TREE_STRING_POINTER (TREE_VALUE (op)), "memory") == 0)
> - ? ? ? ? ? {
> - ? ? ? ? ? ? ?if (dump_file)
> - ? ? ? ? ? ? ? ?fprintf (dump_file, " ? ?memory asm clobber is not const/pure");
> - ? ? ? ? ? ? /* Abandon all hope, ye who enter here. */
> - ? ? ? ? ? ? local->pure_const_state = IPA_NEITHER;
> - ? ? ? ? ? }
> + ? ? ? ? if (dump_file)
> + ? ? ? ? ? fprintf (dump_file, " ? ?memory asm clobber is not const/pure");
> + ? ? ? ? /* Abandon all hope, ye who enter here. */
> + ? ? ? ? local->pure_const_state = IPA_NEITHER;
> ? ? ? ?}
> ? ? ? if (gimple_asm_volatile_p (stmt))
> ? ? ? ?{
> diff --git a/gcc/tree-ssa-operands.c b/gcc/tree-ssa-operands.c
> index 57f443f..7f76cbf 100644
> --- a/gcc/tree-ssa-operands.c
> +++ b/gcc/tree-ssa-operands.c
> @@ -832,15 +832,8 @@ get_asm_expr_operands (gimple stmt)
> ? ? }
>
> ? /* Clobber all memory and addressable symbols for asm ("" : : : "memory"); ?*/
> - ?for (i = 0; i < gimple_asm_nclobbers (stmt); i++)
> - ? ?{
> - ? ? ?tree link = gimple_asm_clobber_op (stmt, i);
> - ? ? ?if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link)), "memory") == 0)
> - ? ? ? {
> - ? ? ? ? add_virtual_operand (stmt, opf_def);
> - ? ? ? ? break;
> - ? ? ? }
> - ? ?}
> + ?if (gimple_asm_clobbers_memory_p (stmt))
> + ? ?add_virtual_operand (stmt, opf_def);
> ?}
>
>
>