Hi Richard,
As per Jakub suggestion in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67326,
the below patch fixes the regression in tree if conversion.
Basically allowing if conversion to happen for a candidate DR, if we find
similar DR with same dimensions and that DR will not trap.
To find similar DRs using hash table to hashing the offset and DR pairs.
Also reusing read/written information that was stored for reference tree.
Also.
(1) I guard these checks for -ftree-loop-if-convert-stores and -fno-common.
Sometimes vectorization flags also triggers if conversion.
(2) Also hashing base DRs for writes only.
gcc/ChangeLog
2015-11-19 Venkataramanan <venkataramanan.ku...@amd.com>
PR tree-optimization/67326
* tree-if-conv.c (offset_DR_map): Define.
(struct ifc_dr): Add new tree base_predicate field.
(hash_memrefs_baserefs_and_store_DRs_read_written_info): Hash offsets,
DR pairs
and hash base ref, DR pairs for write type DRs.
(ifcvt_memrefs_wont_trap): Guard checks with
-ftree-loop-if-convert-stores flag.
Check for similar DR that are accessed unconditionally.
(if_convertible_loop_p_1): Initialize and delete offset hash maps
gcc/testsuite/ChangeLog
2015-11-19 Venkataramanan <venkataramanan.ku...@amd.com>
* gcc.dg/tree-ssa/ifc-pr67326.c: Add new.
Regstrapped on x86_64, Ok for trunk?
Regards,
Venkat.
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ifc-pr67326.c
b/gcc/testsuite/gcc.dg/tree-ssa/ifc-pr67326.c
new file mode 100644
index 0000000..5ca11cd
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ifc-pr67326.c
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-Ofast -fdump-tree-ifcvt-details -fno-common
-ftree-loop-if-convert-stores" } */
+
+float v0[1024];
+float v1[1024];
+float v2[1024];
+float v3[1024];
+
+void condAssign1 () {
+ for (int i=0; i<1024; ++i)
+ v0[i] = (v2[i]>v1[i]) ? v2[i]*v3[i] : v0[i];
+}
+
+void condAssign2 () {
+ for (int i=0; i<1024; ++i)
+ v0[i] = (v2[i]>v1[i]) ? v2[i]*v1[i] : v0[i];
+}
+
+/* { dg-final { scan-tree-dump-times "Applying if-conversion" 2 "ifcvt" } } */
diff --git a/gcc/tree-if-conv.c b/gcc/tree-if-conv.c
index 01065cb..1b4d220 100644
--- a/gcc/tree-if-conv.c
+++ b/gcc/tree-if-conv.c
@@ -124,6 +124,9 @@ static hash_map<tree_operand_hash, data_reference_p>
*ref_DR_map;
/* Hash table to store base reference, DR pairs. */
static hash_map<tree_operand_hash, data_reference_p> *baseref_DR_map;
+/* Hash table to store DR offset, DR pairs. */
+static hash_map<tree_operand_hash, data_reference_p> *offset_DR_map;
+
/* Structure used to predicate basic blocks. This is attached to the
->aux field of the BBs in the loop to be if-converted. */
struct bb_predicate {
@@ -589,6 +592,8 @@ struct ifc_dr {
int rw_unconditionally;
tree predicate;
+
+ tree base_predicate;
};
#define IFC_DR(DR) ((struct ifc_dr *) (DR)->aux)
@@ -609,11 +614,12 @@ static void
hash_memrefs_baserefs_and_store_DRs_read_written_info (data_reference_p a)
{
- data_reference_p *master_dr, *base_master_dr;
+ data_reference_p *master_dr, *base_master_dr, *offset_master_dr;
tree ref = DR_REF (a);
tree base_ref = DR_BASE_OBJECT (a);
+ tree offset = DR_OFFSET (a);
tree ca = bb_predicate (gimple_bb (DR_STMT (a)));
- bool exist1, exist2;
+ bool exist1, exist2, exist3;
while (TREE_CODE (ref) == COMPONENT_REF
|| TREE_CODE (ref) == IMAGPART_EXPR
@@ -636,22 +642,34 @@ hash_memrefs_baserefs_and_store_DRs_read_written_info
(data_reference_p a)
if (is_true_predicate (IFC_DR (*master_dr)->predicate))
DR_RW_UNCONDITIONALLY (*master_dr) = 1;
- base_master_dr = &baseref_DR_map->get_or_insert (base_ref,&exist2);
-
- if (!exist2)
+ if (DR_IS_WRITE (a))
{
- IFC_DR (a)->predicate = ca;
- *base_master_dr = a;
+ base_master_dr = &baseref_DR_map->get_or_insert (base_ref,&exist2);
+ if (!exist2)
+ {
+ IFC_DR (a)->base_predicate = ca;
+ *base_master_dr = a;
+ }
+ else
+ IFC_DR (*base_master_dr)->base_predicate
+ = fold_or_predicates
+ (EXPR_LOCATION (IFC_DR (*base_master_dr)->base_predicate),
+ ca, IFC_DR (*base_master_dr)->base_predicate);
+
+ if (is_true_predicate (IFC_DR (*base_master_dr)->base_predicate))
+ DR_WRITTEN_AT_LEAST_ONCE (*base_master_dr) = 1;
}
- else
- IFC_DR (*base_master_dr)->predicate
- = fold_or_predicates
- (EXPR_LOCATION (IFC_DR (*base_master_dr)->predicate),
- ca, IFC_DR (*base_master_dr)->predicate);
- if (DR_IS_WRITE (a)
- && (is_true_predicate (IFC_DR (*base_master_dr)->predicate)))
- DR_WRITTEN_AT_LEAST_ONCE (*base_master_dr) = 1;
+ if (offset)
+ {
+ offset_master_dr = &offset_DR_map->get_or_insert (offset,&exist3);
+ if (!exist3)
+ *offset_master_dr = a;
+
+ if (DR_RW_UNCONDITIONALLY (*offset_master_dr) != 1)
+ DR_RW_UNCONDITIONALLY (*offset_master_dr)
+ = DR_RW_UNCONDITIONALLY (*master_dr);
+ }
}
/* Return true when the memory references of STMT won't trap in the
@@ -682,7 +700,7 @@ hash_memrefs_baserefs_and_store_DRs_read_written_info
(data_reference_p a)
static bool
ifcvt_memrefs_wont_trap (gimple *stmt, vec<data_reference_p> drs)
{
- data_reference_p *master_dr, *base_master_dr;
+ data_reference_p *master_dr, *base_master_dr, *offset_dr;
data_reference_p a = drs[gimple_uid (stmt) - 1];
tree ref_base_a = DR_REF (a);
@@ -698,21 +716,38 @@ ifcvt_memrefs_wont_trap (gimple *stmt,
vec<data_reference_p> drs)
master_dr = ref_DR_map->get (ref_base_a);
base_master_dr = baseref_DR_map->get (base);
- gcc_assert (master_dr != NULL && base_master_dr != NULL);
+ gcc_assert (master_dr != NULL);
if (DR_RW_UNCONDITIONALLY (*master_dr) == 1)
{
- if (DR_WRITTEN_AT_LEAST_ONCE (*base_master_dr) == 1)
+ if ((base_master_dr
+ && DR_WRITTEN_AT_LEAST_ONCE (*base_master_dr) == 1))
return true;
else
{
tree base_tree = get_base_address (DR_REF (a));
if (DECL_P (base_tree)
&& decl_binds_to_current_def_p (base_tree)
+ && flag_tree_loop_if_convert_stores
&& !TREE_READONLY (base_tree))
return true;
}
}
+ else if (DR_OFFSET (a))
+ {
+ offset_dr = offset_DR_map->get (DR_OFFSET (a));
+ if ((DR_RW_UNCONDITIONALLY (*offset_dr) == 1)
+ && DR_NUM_DIMENSIONS (a) == DR_NUM_DIMENSIONS (*offset_dr))
+ {
+ tree base_tree = get_base_address (DR_REF (a));
+ if (DECL_P (base_tree)
+ && flag_tree_loop_if_convert_stores
+ && decl_binds_to_current_def_p (base_tree)
+ && !TREE_READONLY (base_tree))
+ return true;
+ }
+ }
+
return false;
}
@@ -1267,6 +1302,7 @@ if_convertible_loop_p_1 (struct loop *loop,
ref_DR_map = new hash_map<tree_operand_hash, data_reference_p>;
baseref_DR_map = new hash_map<tree_operand_hash, data_reference_p>;
+ offset_DR_map = new hash_map<tree_operand_hash, data_reference_p>;
predicate_bbs (loop);
@@ -1382,6 +1418,9 @@ if_convertible_loop_p (struct loop *loop, bool
*any_mask_load_store)
delete baseref_DR_map;
baseref_DR_map = NULL;
+ delete offset_DR_map;
+ offset_DR_map = NULL;
+
return res;
}
