diff mbox

[v2,10/13] Avoid CSE of MEMs in different address spaces

Message ID 1445376433-14658-11-git-send-email-rth@redhat.com
State New
Headers show

Commit Message

Richard Henderson Oct. 20, 2015, 9:27 p.m. UTC 
---
 gcc/cselib.c                                 | 22 +++++++++++++---------
 gcc/fold-const.c                             | 14 +++++++-------
 gcc/testsuite/gcc.target/i386/addr-space-2.c | 11 +++++++++++
 3 files changed, 31 insertions(+), 16 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/addr-space-2.c

Comments

Jeff Law Oct. 21, 2015, 1:37 p.m. UTC | #1 
On 10/20/2015 03:27 PM, Richard Henderson wrote:
> ---
>   gcc/cselib.c                                 | 22 +++++++++++++---------
>   gcc/fold-const.c                             | 14 +++++++-------
>   gcc/testsuite/gcc.target/i386/addr-space-2.c | 11 +++++++++++
>   3 files changed, 31 insertions(+), 16 deletions(-)
>   create mode 100644 gcc/testsuite/gcc.target/i386/addr-space-2.c
This part is fine.  Does the one testcase cover both the cselib.c & 
fold-const.c fix?  If not, it'd be good to cover both if we can.


jeff
Richard Henderson Oct. 21, 2015, 5:12 p.m. UTC | #2 
On 10/21/2015 03:37 AM, Jeff Law wrote:
> On 10/20/2015 03:27 PM, Richard Henderson wrote:
>> ---
>>   gcc/cselib.c                                 | 22 +++++++++++++---------
>>   gcc/fold-const.c                             | 14 +++++++-------
>>   gcc/testsuite/gcc.target/i386/addr-space-2.c | 11 +++++++++++
>>   3 files changed, 31 insertions(+), 16 deletions(-)
>>   create mode 100644 gcc/testsuite/gcc.target/i386/addr-space-2.c
> This part is fine.  Does the one testcase cover both the cselib.c &
> fold-const.c fix?  If not, it'd be good to cover both if we can.

Yes it does.

The fold-const fix gets us as far as .optimized, but then the cselib fix gets 
us past postreload-cse.


r~
Richard Biener Oct. 22, 2015, 7:43 a.m. UTC | #3 
On Wed, Oct 21, 2015 at 7:12 PM, Richard Henderson <rth@redhat.com> wrote:
> On 10/21/2015 03:37 AM, Jeff Law wrote:
>>
>> On 10/20/2015 03:27 PM, Richard Henderson wrote:
>>>
>>> ---
>>>   gcc/cselib.c                                 | 22
>>> +++++++++++++---------
>>>   gcc/fold-const.c                             | 14 +++++++-------
>>>   gcc/testsuite/gcc.target/i386/addr-space-2.c | 11 +++++++++++
>>>   3 files changed, 31 insertions(+), 16 deletions(-)
>>>   create mode 100644 gcc/testsuite/gcc.target/i386/addr-space-2.c
>>
>> This part is fine.  Does the one testcase cover both the cselib.c &
>> fold-const.c fix?  If not, it'd be good to cover both if we can.
>
>
> Yes it does.
>
> The fold-const fix gets us as far as .optimized, but then the cselib fix
> gets us past postreload-cse.

These fixes are appropriate for backporting as well I think.

Richard.
>
> r~
diff mbox

Patch

diff --git a/gcc/cselib.c b/gcc/cselib.c
index 4264394..857e52a 100644
--- a/gcc/cselib.c
+++ b/gcc/cselib.c
@@ -1337,15 +1337,15 @@  new_cselib_val (unsigned int hash, machine_mode mode, rtx x)
 static void
 add_mem_for_addr (cselib_val *addr_elt, cselib_val *mem_elt, rtx x)
 {
-  struct elt_loc_list *l;
-
   addr_elt = canonical_cselib_val (addr_elt);
   mem_elt = canonical_cselib_val (mem_elt);
 
   /* Avoid duplicates.  */
-  for (l = mem_elt->locs; l; l = l->next)
+  addr_space_t as = MEM_ADDR_SPACE (x);
+  for (elt_loc_list *l = mem_elt->locs; l; l = l->next)
     if (MEM_P (l->loc)
-	&& CSELIB_VAL_PTR (XEXP (l->loc, 0)) == addr_elt)
+	&& CSELIB_VAL_PTR (XEXP (l->loc, 0)) == addr_elt
+        && MEM_ADDR_SPACE (l->loc) == as)
       {
 	promote_debug_loc (l);
 	return;
@@ -1372,7 +1372,6 @@  cselib_lookup_mem (rtx x, int create)
   cselib_val **slot;
   cselib_val *addr;
   cselib_val *mem_elt;
-  struct elt_list *l;
 
   if (MEM_VOLATILE_P (x) || mode == BLKmode
       || !cselib_record_memory
@@ -1387,14 +1386,19 @@  cselib_lookup_mem (rtx x, int create)
   addr = cselib_lookup (XEXP (x, 0), addr_mode, create, mode);
   if (! addr)
     return 0;
-
   addr = canonical_cselib_val (addr);
+
   /* Find a value that describes a value of our mode at that address.  */
-  for (l = addr->addr_list; l; l = l->next)
+  addr_space_t as = MEM_ADDR_SPACE (x);
+  for (elt_list *l = addr->addr_list; l; l = l->next)
     if (GET_MODE (l->elt->val_rtx) == mode)
       {
-	promote_debug_loc (l->elt->locs);
-	return l->elt;
+	for (elt_loc_list *l2 = l->elt->locs; l2; l2 = l2->next)
+	  if (MEM_P (l2->loc) && MEM_ADDR_SPACE (l2->loc) == as)
+	    {
+	      promote_debug_loc (l->elt->locs);
+	      return l->elt;
+	    }
       }
 
   if (! create)
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index eb7edca..6da4010 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -2718,6 +2718,13 @@  operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
   if (!TREE_TYPE (arg0) || !TREE_TYPE (arg1))
     return 0;
 
+  /* We cannot consider pointers to different address space equal.  */
+  if (POINTER_TYPE_P (TREE_TYPE (arg0))
+      && POINTER_TYPE_P (TREE_TYPE (arg1))
+      && (TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (arg0)))
+	  != TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (arg1)))))
+    return 0;
+
   /* Check equality of integer constants before bailing out due to
      precision differences.  */
   if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
@@ -2741,13 +2748,6 @@  operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
 			     != POINTER_TYPE_P (TREE_TYPE (arg1)))
 	return 0;
 
-      /* We cannot consider pointers to different address space equal.  */
-      if (POINTER_TYPE_P (TREE_TYPE (arg0))
-			  && POINTER_TYPE_P (TREE_TYPE (arg1))
-	  && (TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (arg0)))
-	      != TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (arg1)))))
-	return 0;
-
       /* If both types don't have the same precision, then it is not safe
 	 to strip NOPs.  */
       if (element_precision (TREE_TYPE (arg0))
diff --git a/gcc/testsuite/gcc.target/i386/addr-space-2.c b/gcc/testsuite/gcc.target/i386/addr-space-2.c
new file mode 100644
index 0000000..d5c24b6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/addr-space-2.c
@@ -0,0 +1,11 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+/* { dg-final { scan-assembler "fs:16" } } */
+/* { dg-final { scan-assembler "gs:16" } } */
+
+int test(void)
+{
+  int __seg_fs *f = (int __seg_fs *)16;
+  int __seg_gs *g = (int __seg_gs *)16;
+  return *f + *g;
+}