re PR tree-optimization/67955 (tree-dse does not use pointer info)

PR tree-optimizatin/67955
	* tree-ssa-alias.c (same_addr_size_stores_p): Check offsets first.
	Allow any SSA_VAR_P as the base objects.  Use integer_zerop.  Verify
	the points-to solution does not include pt_null.  Use DECL_PT_UID
	unconditionally.

	PR tree-optimization/67955
	* gcc.dg/tree-ssa/ssa-dse-28.c: New test.

From-SVN: r244067
This commit is contained in:
Jeff Law 2017-01-04 12:22:44 -07:00 committed by Jeff Law
parent baf9ebc8cc
commit 8194635af7
4 changed files with 47 additions and 11 deletions

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@ -1,3 +1,11 @@
2017-01-04 Jeff Law <law@redhat.com>
PR tree-optimizatin/67955
* tree-ssa-alias.c (same_addr_size_stores_p): Check offsets first.
Allow any SSA_VAR_P as the base objects. Use integer_zerop. Verify
the points-to solution does not include pt_null. Use DECL_PT_UID
unconditionally.
2017-01-04 Uros Bizjak <ubizjak@gmail.com>
* config/i386/i386.md (HI/SImode test with imm to QImode splitters):

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@ -1,3 +1,8 @@
2017-01-03 Jeff Law <law@redhat.com>
PR tree-optimization/67955
* gcc.dg/tree-ssa/ssa-dse-28.c: New test.
2017-01-04 Marek Polacek <polacek@redhat.com>
PR c++/77545

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@ -0,0 +1,20 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-dse-details -fexceptions -fnon-call-exceptions -fno-isolate-erroneous-paths-dereference" } */
int foo (int *p, int b)
{
int *q;
int i = 1;
if (b)
q = &i;
else
q = (void *)0;
*q = 2;
return i;
}
/* { dg-final { scan-tree-dump-not "Deleted dead store" "dse1"} } */
/* { dg-final { scan-tree-dump-not "Deleted dead store" "dse2"} } */
/* { dg-final { scan-tree-dump-not "Deleted dead store" "dse3"} } */

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@ -2326,9 +2326,13 @@ same_addr_size_stores_p (tree base1, HOST_WIDE_INT offset1, HOST_WIDE_INT size1,
tree base2, HOST_WIDE_INT offset2, HOST_WIDE_INT size2,
HOST_WIDE_INT max_size2)
{
/* For now, just handle VAR_DECL. */
bool base1_obj_p = VAR_P (base1);
bool base2_obj_p = VAR_P (base2);
/* Offsets need to be 0. */
if (offset1 != 0
|| offset2 != 0)
return false;
bool base1_obj_p = SSA_VAR_P (base1);
bool base2_obj_p = SSA_VAR_P (base2);
/* We need one object. */
if (base1_obj_p == base2_obj_p)
@ -2356,13 +2360,9 @@ same_addr_size_stores_p (tree base1, HOST_WIDE_INT offset1, HOST_WIDE_INT size1,
if (size1 != size2)
return false;
/* Offsets need to be 0. */
if (offset1 != 0
|| offset2 != 0)
return false;
/* Check that memref is a store to pointer with singleton points-to info. */
if (!tree_int_cst_equal (TREE_OPERAND (memref, 1), integer_zero_node))
if (!integer_zerop (TREE_OPERAND (memref, 1)))
return false;
tree ptr = TREE_OPERAND (memref, 0);
if (TREE_CODE (ptr) != SSA_NAME)
@ -2373,10 +2373,13 @@ same_addr_size_stores_p (tree base1, HOST_WIDE_INT offset1, HOST_WIDE_INT size1,
|| !pt_solution_singleton_or_null_p (&pi->pt, &pt_uid))
return false;
/* If the solution has a singleton and NULL, then we can not
be sure that the two stores hit the same address. */
if (pi->pt.null)
return false;
/* Check that ptr points relative to obj. */
unsigned int obj_uid = (DECL_PT_UID_SET_P (obj)
? DECL_PT_UID (obj)
: DECL_UID (obj));
unsigned int obj_uid = DECL_PT_UID (obj);
if (obj_uid != pt_uid)
return false;