On Tue, 21 May 2019, Richard Biener wrote:
> And that should be done at RTL creation time instead of
> repeatedly over and over. Like with the following.
>
> Bootstrap / regtest on x86_64-unknown-linux-gnu in progress.
But we can't get away w/o unsharing the expr we change so committed
as follows after Bootstrap / regtest on x86_64-unknown-linux-gnu.
Richard.
2019-05-22 Richard Biener <rguent...@suse.de>
* alias.c (ao_ref_from_mem): Move stack-slot sharing
rewrite ...
* emit-rtl.c (set_mem_attributes_minus_bitpos): ... here.
Index: gcc/alias.c
===================================================================
--- gcc/alias.c (revision 271500)
+++ gcc/alias.c (working copy)
@@ -307,18 +307,6 @@ ao_ref_from_mem (ao_ref *ref, const_rtx
&& TREE_CODE (TMR_BASE (base)) == SSA_NAME)))
return false;
- /* If this is a reference based on a partitioned decl replace the
- base with a MEM_REF of the pointer representative we
- created during stack slot partitioning. */
- if (VAR_P (base)
- && ! is_global_var (base)
- && cfun->gimple_df->decls_to_pointers != NULL)
- {
- tree *namep = cfun->gimple_df->decls_to_pointers->get (base);
- if (namep)
- ref->base = build_simple_mem_ref (*namep);
- }
-
ref->ref_alias_set = MEM_ALIAS_SET (mem);
/* If MEM_OFFSET or MEM_SIZE are unknown what we got from MEM_EXPR
Index: gcc/emit-rtl.c
===================================================================
--- gcc/emit-rtl.c (revision 271500)
+++ gcc/emit-rtl.c (working copy)
@@ -61,6 +61,9 @@ along with GCC; see the file COPYING3.
#include "opts.h"
#include "predict.h"
#include "rtx-vector-builder.h"
+#include "gimple.h"
+#include "gimple-ssa.h"
+#include "gimplify.h"
struct target_rtl default_target_rtl;
#if SWITCHABLE_TARGET
@@ -2128,6 +2131,27 @@ set_mem_attributes_minus_bitpos (rtx ref
apply_bitpos = bitpos;
}
+ /* If this is a reference based on a partitioned decl replace the
+ base with a MEM_REF of the pointer representative we created
+ during stack slot partitioning. */
+ if (attrs.expr
+ && VAR_P (base)
+ && ! is_global_var (base)
+ && cfun->gimple_df->decls_to_pointers != NULL)
+ {
+ tree *namep = cfun->gimple_df->decls_to_pointers->get (base);
+ if (namep)
+ {
+ attrs.expr = unshare_expr (attrs.expr);
+ tree *orig_base = &attrs.expr;
+ while (handled_component_p (*orig_base))
+ orig_base = &TREE_OPERAND (*orig_base, 0);
+ tree aptrt = reference_alias_ptr_type (*orig_base);
+ *orig_base = build2 (MEM_REF, TREE_TYPE (*orig_base), *namep,
+ build_int_cst (aptrt, 0));
+ }
+ }
+
/* Compute the alignment. */
unsigned int obj_align;
unsigned HOST_WIDE_INT obj_bitpos;
