This makes IPA ICF compare alignment of accesses.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2015-03-02 Richard Biener <rguent...@suse.de>
PR ipa/65270
* ipa-icf-gimple.c: Include builtins.h.
(func_checker::compare_memory_operand): Compare base alignment.
Index: gcc/ipa-icf-gimple.c
===================================================================
--- gcc/ipa-icf-gimple.c (revision 221100)
+++ gcc/ipa-icf-gimple.c (working copy)
@@ -77,6 +77,7 @@ along with GCC; see the file COPYING3.
#include <list>
#include "tree-ssanames.h"
#include "tree-eh.h"
+#include "builtins.h"
#include "ipa-icf-gimple.h"
#include "ipa-icf.h"
@@ -286,6 +287,24 @@ func_checker::compare_memory_operand (tr
if (ao_ref_alias_set (&r1) != ao_ref_alias_set (&r2)
|| ao_ref_base_alias_set (&r1) != ao_ref_base_alias_set (&r2))
return return_false_with_msg ("ao alias sets are different");
+
+ /* We can't simply use get_object_alignment_1 on the full
+ reference as for accesses with variable indexes this reports
+ too conservative alignment. We also can't use the ao_ref_base
+ base objects as ao_ref_base happily strips MEM_REFs around
+ decls even though that may carry alignment info. */
+ b1 = t1;
+ while (handled_component_p (b1))
+ b1 = TREE_OPERAND (b1, 0);
+ b2 = t2;
+ while (handled_component_p (b2))
+ b2 = TREE_OPERAND (b2, 0);
+ unsigned int align1, align2;
+ unsigned HOST_WIDE_INT tem;
+ get_object_alignment_1 (b1, &align1, &tem);
+ get_object_alignment_1 (b2, &align2, &tem);
+ if (align1 != align2)
+ return return_false_with_msg ("different access alignment");
}
return compare_operand (t1, t2);
