diff options
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/alias.c | 3 | ||||
| -rw-r--r-- | gcc/alias.h | 1 | ||||
| -rw-r--r-- | gcc/cse.c | 17 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr35258.c | 28 |
6 files changed, 59 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 13ca11e..fa691e7 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2008-02-25 Andreas Krebbel <krebbel1@de.ibm.com> + + PR target/35258 + * cse.c (cse_insn): Avoid creation of overlapping MEMs. + * alias.c (nonoverlapping_memrefs_p): Export for use in other modules. + * alias.h (nonoverlapping_memrefs_p): Likewise. + 2008-02-25 Jan Beulich <jbeulich@novell.com> * Makefile.in: Also prefix uses of crt0.o and mcrt0.o with diff --git a/gcc/alias.c b/gcc/alias.c index bd5c277..56afa86 100644 --- a/gcc/alias.c +++ b/gcc/alias.c @@ -164,7 +164,6 @@ static int aliases_everything_p (const_rtx); static bool nonoverlapping_component_refs_p (const_tree, const_tree); static tree decl_for_component_ref (tree); static rtx adjust_offset_for_component_ref (tree, rtx); -static int nonoverlapping_memrefs_p (const_rtx, const_rtx); static int write_dependence_p (const_rtx, const_rtx, int); static void memory_modified_1 (rtx, const_rtx, void *); @@ -1976,7 +1975,7 @@ adjust_offset_for_component_ref (tree x, rtx offset) /* Return nonzero if we can determine the exprs corresponding to memrefs X and Y and they do not overlap. */ -static int +int nonoverlapping_memrefs_p (const_rtx x, const_rtx y) { tree exprx = MEM_EXPR (x), expry = MEM_EXPR (y); diff --git a/gcc/alias.h b/gcc/alias.h index a245493..772aea0 100644 --- a/gcc/alias.h +++ b/gcc/alias.h @@ -28,6 +28,7 @@ extern alias_set_type get_varargs_alias_set (void); extern alias_set_type get_frame_alias_set (void); extern bool component_uses_parent_alias_set (const_tree); extern bool alias_set_subset_of (alias_set_type, alias_set_type); +extern int nonoverlapping_memrefs_p (const_rtx, const_rtx); /* This alias set can be used to force a memory to conflict with all other memories, creating a barrier across which no memory reference @@ -4753,6 +4753,23 @@ cse_insn (rtx insn, rtx libcall_insn) src_elt_cost = MAX_COST; } + /* Avoid creation of overlapping memory moves. */ + if (MEM_P (trial) && MEM_P (SET_DEST (sets[i].rtl))) + { + rtx src, dest; + + /* BLKmode moves are not handled by cse anyway. */ + if (GET_MODE (trial) == BLKmode) + break; + + src = canon_rtx (trial); + dest = canon_rtx (SET_DEST (sets[i].rtl)); + + if (!MEM_P (src) || !MEM_P (dest) + || !nonoverlapping_memrefs_p (src, dest)) + break; + } + /* We don't normally have an insn matching (set (pc) (pc)), so check for this separately here. We will delete such an insn below. diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index cc2d87c..0e3977d 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2008-02-25 Andreas Krebbel <krebbel1@de.ibm.com> + + PR target/35258 + * gcc.dg/pr35258.c: New testcase. + 2008-02-25 Jan Beulich <jbeulich@novell.com> * gcc.dg/20020426-2.c: Remove bogus workaround. diff --git a/gcc/testsuite/gcc.dg/pr35258.c b/gcc/testsuite/gcc.dg/pr35258.c new file mode 100644 index 0000000..d1c45a7 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr35258.c @@ -0,0 +1,28 @@ +/* { dg-do run } */ +/* { dg-options "-O1" } */ + +extern void *memcpy (void *, const void *, __SIZE_TYPE__); +extern int memcmp (const void *, const void *, __SIZE_TYPE__); +extern void abort(void); + +char str[9] = "1234"; + +void +bar (void) +{ + unsigned int temp; + char *p = &str[2]; + + memcpy (&temp, &str[1], 4); + memcpy (p, &temp, 4); + str[1] = '.'; +} + +int main() +{ + bar(); + if (memcmp (str, "1.234", 5) != 0) + abort (); + + return 0; +} |