The "do fancy stuff" routine failed to look at the valueized LHS
in some cases which makes it regress at -O2 compared to -O1
(because with -O1 all preceeding stmts have gone through elimination
already).
Noticed when working on aarch64 support for PR83518.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2019-07-10 Richard Biener <rguent...@suse.de>
c/
* gimple-parser.c (c_parser_gimple_postfix_expression): Support
_Literal (int *) &x for address literals.
* tree-ssa-sccvn.c (vn_reference_lookup_3): Look at valueized
LHS whenever possible.
* gcc.dg/torture/ssa-fre-5.c: New testcase.
* gcc.dg/torture/ssa-fre-6.c: Likewise.
* gcc.dg/torture/ssa-fre-7.c: Likewise.
Index: gcc/c/gimple-parser.c
===================================================================
--- gcc/c/gimple-parser.c (revision 273353)
+++ gcc/c/gimple-parser.c (working copy)
@@ -1606,8 +1606,10 @@ c_parser_gimple_postfix_expression (gimp
tree val = c_parser_gimple_postfix_expression (parser).value;
if (! val
|| val == error_mark_node
- || ! CONSTANT_CLASS_P (val)
- || (addr_p && TREE_CODE (val) != STRING_CST))
+ || (!CONSTANT_CLASS_P (val)
+ && !(addr_p
+ && (TREE_CODE (val) == STRING_CST
+ || DECL_P (val)))))
{
c_parser_error (parser, "invalid _Literal");
return expr;
Index: gcc/testsuite/gcc.dg/torture/ssa-fre-5.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/ssa-fre-5.c (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/ssa-fre-5.c (working copy)
@@ -0,0 +1,27 @@
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } { "" } } */
+/* { dg-additional-options "-fgimple -fdump-tree-fre1" } */
+
+typedef int v4si __attribute__((vector_size(16)));
+
+int __GIMPLE (ssa,startwith("fre"))
+foo ()
+{
+ int * p;
+ int i;
+ int x[4];
+ long unsigned int _1;
+ long unsigned int _2;
+ int _7;
+
+ __BB(2):
+ i_3 = 0;
+ _1 = (long unsigned int) i_3;
+ _2 = _1 * 4ul;
+ p_4 = _Literal (int *) &x + _2;
+ __MEM <v4si> ((v4si *)p_4) = _Literal (v4si) { 1, 2, 3, 4 };
+ _7 = x[0];
+ return _7;
+}
+
+/* { dg-final { scan-tree-dump "return 1;" "fre1" } } */
Index: gcc/testsuite/gcc.dg/torture/ssa-fre-6.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/ssa-fre-6.c (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/ssa-fre-6.c (working copy)
@@ -0,0 +1,27 @@
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } { "" } } */
+/* { dg-additional-options "-fgimple -fdump-tree-fre1" } */
+
+typedef int v4si __attribute__((vector_size(16)));
+
+int __GIMPLE (ssa,startwith("fre"))
+foo ()
+{
+ int * p;
+ int i;
+ int x[4];
+ long unsigned int _1;
+ long unsigned int _2;
+ int _7;
+
+ __BB(2):
+ i_3 = 0;
+ _1 = (long unsigned int) i_3;
+ _2 = _1 * 4ul;
+ p_4 = _Literal (int *) &x + _2;
+ __MEM <v4si> ((v4si *)p_4) = _Literal (v4si) {};
+ _7 = x[0];
+ return _7;
+}
+
+/* { dg-final { scan-tree-dump "return 0;" "fre1" } } */
Index: gcc/testsuite/gcc.dg/torture/ssa-fre-7.c
===================================================================
--- gcc/testsuite/gcc.dg/torture/ssa-fre-7.c (nonexistent)
+++ gcc/testsuite/gcc.dg/torture/ssa-fre-7.c (working copy)
@@ -0,0 +1,29 @@
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-O0" } { "" } } */
+/* { dg-additional-options "-fgimple -fdump-tree-fre1" } */
+
+typedef int v4si __attribute__((vector_size(16)));
+
+int __GIMPLE (ssa,startwith("fre"))
+foo (int c)
+{
+ int * p;
+ int i;
+ int x[4];
+ long unsigned int _1;
+ long unsigned int _2;
+ int _7;
+ v4si _6;
+
+ __BB(2):
+ i_3 = 0;
+ _1 = (long unsigned int) i_3;
+ _2 = _1 * 4ul;
+ p_4 = _Literal (int *) &x + _2;
+ _6 = _Literal (v4si) { c_5(D), c_5(D), c_5(D), c_5(D) };
+ __MEM <v4si> ((v4si *)p_4) = _6;
+ _7 = x[0];
+ return _7;
+}
+
+/* { dg-final { scan-tree-dump "return c_5\\(D\\);" "fre1" } } */
Index: gcc/tree-ssa-sccvn.c
===================================================================
--- gcc/tree-ssa-sccvn.c (revision 273353)
+++ gcc/tree-ssa-sccvn.c (working copy)
@@ -2488,12 +2488,22 @@ vn_reference_lookup_3 (ao_ref *ref, tree
&& gimple_assign_rhs_code (def_stmt) == CONSTRUCTOR
&& CONSTRUCTOR_NELTS (gimple_assign_rhs1 (def_stmt)) == 0)
{
+ tree lhs = gimple_assign_lhs (def_stmt);
tree base2;
poly_int64 offset2, size2, maxsize2;
HOST_WIDE_INT offset2i, size2i;
bool reverse;
- base2 = get_ref_base_and_extent (gimple_assign_lhs (def_stmt),
- &offset2, &size2, &maxsize2, &reverse);
+ if (lhs_ref_ok)
+ {
+ base2 = ao_ref_base (&lhs_ref);
+ offset2 = lhs_ref.offset;
+ size2 = lhs_ref.size;
+ maxsize2 = lhs_ref.max_size;
+ reverse = reverse_storage_order_for_component_p (lhs);
+ }
+ else
+ base2 = get_ref_base_and_extent (lhs,
+ &offset2, &size2, &maxsize2, &reverse);
if (known_size_p (maxsize2)
&& known_eq (maxsize2, size2)
&& adjust_offsets_for_equal_base_address (base, &offset,
@@ -2541,12 +2551,22 @@ vn_reference_lookup_3 (ao_ref *ref, tree
|| (TREE_CODE (gimple_assign_rhs1 (def_stmt)) == SSA_NAME
&& is_gimple_min_invariant (SSA_VAL (gimple_assign_rhs1
(def_stmt))))))
{
+ tree lhs = gimple_assign_lhs (def_stmt);
tree base2;
poly_int64 offset2, size2, maxsize2;
HOST_WIDE_INT offset2i, size2i;
bool reverse;
- base2 = get_ref_base_and_extent (gimple_assign_lhs (def_stmt),
- &offset2, &size2, &maxsize2, &reverse);
+ if (lhs_ref_ok)
+ {
+ base2 = ao_ref_base (&lhs_ref);
+ offset2 = lhs_ref.offset;
+ size2 = lhs_ref.size;
+ maxsize2 = lhs_ref.max_size;
+ reverse = reverse_storage_order_for_component_p (lhs);
+ }
+ else
+ base2 = get_ref_base_and_extent (lhs,
+ &offset2, &size2, &maxsize2, &reverse);
if (base2
&& !reverse
&& known_eq (maxsize2, size2)
@@ -2627,12 +2647,21 @@ vn_reference_lookup_3 (ao_ref *ref, tree
downstream, not so much for actually doing the insertion. */
&& data->partial_defs.is_empty ())
{
+ tree lhs = gimple_assign_lhs (def_stmt);
tree base2;
poly_int64 offset2, size2, maxsize2;
bool reverse;
- base2 = get_ref_base_and_extent (gimple_assign_lhs (def_stmt),
- &offset2, &size2, &maxsize2,
- &reverse);
+ if (lhs_ref_ok)
+ {
+ base2 = ao_ref_base (&lhs_ref);
+ offset2 = lhs_ref.offset;
+ size2 = lhs_ref.size;
+ maxsize2 = lhs_ref.max_size;
+ reverse = reverse_storage_order_for_component_p (lhs);
+ }
+ else
+ base2 = get_ref_base_and_extent (lhs,
+ &offset2, &size2, &maxsize2, &reverse);
tree def_rhs = gimple_assign_rhs1 (def_stmt);
if (!reverse
&& known_size_p (maxsize2)
