@@ -1,3 +1,9 @@
+2018-12-10 Jeff Law <law@redhat.com>
+
+ PR tree-optimization/80520
+ * gimple-ssa-split-paths.c (is_feasible_trace): Recognize half
+ diamonds that are likely if convertable.
+
2018-12-10 Martin Sebor <msebor@redhat.com>
PR tree-optimization/86196
@@ -203,6 +203,98 @@ is_feasible_trace (basic_block bb)
}
}
+ /* Canonicalize the form. */
+ if (num_stmts_in_pred1 == 0 && num_stmts_in_pred2 == 1)
+ {
+ std::swap (pred1, pred2);
+ std::swap (num_stmts_in_pred1, num_stmts_in_pred2);
+ }
+
+ /* Another variant. This one is half-diamond. */
+ if (num_stmts_in_pred1 == 1 && num_stmts_in_pred2 == 0
+ && dominated_by_p (CDI_DOMINATORS, pred1, pred2))
+ {
+ gimple *stmt1 = last_and_only_stmt (pred1);
+
+ /* The only statement in PRED1 must be an assignment that is
+ not a good candidate for if-conversion. This may need some
+ generalization. */
+ if (stmt1 && gimple_code (stmt1) == GIMPLE_ASSIGN)
+ {
+ enum tree_code code1 = gimple_assign_rhs_code (stmt1);
+
+ if (!poor_ifcvt_candidate_code (code1))
+ {
+ tree lhs1 = gimple_assign_lhs (stmt1);
+ tree rhs1 = gimple_assign_rhs1 (stmt1);
+
+ gimple_stmt_iterator gsi;
+ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple *phi = gsi_stmt (gsi);
+ if ((gimple_phi_arg_def (phi, 0) == lhs1
+ && gimple_phi_arg_def (phi, 1) == rhs1)
+ || (gimple_phi_arg_def (phi, 1) == lhs1
+ && gimple_phi_arg_def (phi, 0) == rhs1))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "Block %d appears to be a join point for "
+ "if-convertable half-diamond.\n",
+ bb->index);
+ return false;
+ }
+ }
+ }
+ }
+ }
+
+ /* Canonicalize the form. */
+ if (num_stmts_in_pred1 == 0 && num_stmts_in_pred2 == 1)
+ {
+ std::swap (pred1, pred2);
+ std::swap (num_stmts_in_pred1, num_stmts_in_pred2);
+ }
+
+ /* Another variant. This one is half-diamond. */
+ if (num_stmts_in_pred1 == 1 && num_stmts_in_pred2 == 0
+ && dominated_by_p (CDI_DOMINATORS, pred1, pred2))
+ {
+ gimple *stmt1 = last_and_only_stmt (pred1);
+
+ /* The only statement in PRED1 must be an assignment that is
+ not a good candidate for if-conversion. This may need some
+ generalization. */
+ if (stmt1 && gimple_code (stmt1) == GIMPLE_ASSIGN)
+ {
+ enum tree_code code1 = gimple_assign_rhs_code (stmt1);
+
+ if (!poor_ifcvt_candidate_code (code1))
+ {
+ tree lhs1 = gimple_assign_lhs (stmt1);
+ tree rhs1 = gimple_assign_rhs1 (stmt1);
+
+ gimple_stmt_iterator gsi;
+ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple *phi = gsi_stmt (gsi);
+ if ((gimple_phi_arg_def (phi, 0) == lhs1
+ && gimple_phi_arg_def (phi, 1) == rhs1)
+ || (gimple_phi_arg_def (phi, 1) == lhs1
+ && gimple_phi_arg_def (phi, 0) == rhs1))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "Block %d appears to be a join point for "
+ "if-convertable half-diamond.\n",
+ bb->index);
+ return false;
+ }
+ }
+ }
+ }
+ }
+
/* If the joiner has no PHIs with useful uses there is zero chance
of CSE/DCE/jump-threading possibilities exposed by duplicating it. */
bool found_useful_phi = false;
@@ -1,3 +1,9 @@
+2018-12-10 Jeff Law <law@redhat.com>
+
+ PR tree-optimization/80520
+ * gcc.dg/tree-ssa/split-path-5.c: Update expected output.
+ * gcc.dg/tree-ssa/split-path-11.c: New test.
+
2018-12-10 Steven G. Kargl <kargl@gcc.gnu.org>
PR fortran/97922
new file mode 100644
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fsplit-paths -fdump-tree-split-paths-details -w" } */
+
+void foo(unsigned long *M)
+{
+ for (unsigned long k = 0; k < 227; ++k)
+ {
+ unsigned long y =
+ ((M[k] & 0xffffffff80000000) | (M[k + 1] & 0x7fffffff));
+ M[k] = (M[k + 397] ^ (y >> 1) ^ ((y & 1) ? 2567483615 : 0));
+ }
+}
+
+/* { dg-final { scan-tree-dump-times "join point for if-convertable half-diamond" 1 "split-paths" } } */
@@ -41,4 +41,4 @@ bmhi_init (const char *pattern)
}
}
-/* { dg-final { scan-tree-dump-times "Duplicating join block" 1 "split-paths" } } */
+/* { dg-final { scan-tree-dump-times "join point for if-convertable half-diamond" 1 "split-paths" } } */