8273277: C2: Move conditional negation into rc_predicate

Reviewed-by: thartmann, chagedorn, kvn

Author: Nils Eliasson

src/hotspot/share/opto/loopPredicate.cpp

@@ -802,7 +802,7 @@ bool IdealLoopTree::is_range_check_if(IfNode *iff, PhaseIdealLoop *phase, Invari
 BoolNode* PhaseIdealLoop::rc_predicate(IdealLoopTree *loop, Node* ctrl,
                                        int scale, Node* offset,
                                        Node* init, Node* limit, jint stride,
-                                       Node* range, bool upper, bool &overflow) {
+                                       Node* range, bool upper, bool &overflow, bool negate) {
   jint con_limit  = (limit != NULL && limit->is_Con())  ? limit->get_int()  : 0;
   jint con_init   = init->is_Con()   ? init->get_int()   : 0;
   jint con_offset = offset->is_Con() ? offset->get_int() : 0;
@@ -928,7 +928,7 @@ BoolNode* PhaseIdealLoop::rc_predicate(IdealLoopTree *loop, Node* ctrl,
     cmp = new CmpUNode(max_idx_expr, range);
   }
   register_new_node(cmp, ctrl);
-  BoolNode* bol = new BoolNode(cmp, BoolTest::lt);
+  BoolNode* bol = new BoolNode(cmp, negate ? BoolTest::ge : BoolTest::lt);
   register_new_node(bol, ctrl);
 
   if (TraceLoopPredicate) {
@@ -1295,36 +1295,26 @@ bool PhaseIdealLoop::loop_predication_impl_helper(IdealLoopTree *loop, ProjNode*
     }
     // If predicate expressions may overflow in the integer range, longs are used.
     bool overflow = false;
+    bool negate = (proj->_con != predicate_proj->_con);
 
     // Test the lower bound
-    BoolNode* lower_bound_bol = rc_predicate(loop, ctrl, scale, offset, init, limit, stride, rng, false, overflow);
-    // Negate test if necessary
-    bool negated = false;
-    if (proj->_con != predicate_proj->_con) {
-      lower_bound_bol = new BoolNode(lower_bound_bol->in(1), lower_bound_bol->_test.negate());
-      register_new_node(lower_bound_bol, ctrl);
-      negated = true;
-    }
+    BoolNode* lower_bound_bol = rc_predicate(loop, ctrl, scale, offset, init, limit, stride, rng, false, overflow, negate);
+
     ProjNode* lower_bound_proj = create_new_if_for_predicate(predicate_proj, NULL, reason, overflow ? Op_If : iff->Opcode());
     IfNode* lower_bound_iff = lower_bound_proj->in(0)->as_If();
     _igvn.hash_delete(lower_bound_iff);
     lower_bound_iff->set_req(1, lower_bound_bol);
-    if (TraceLoopPredicate) tty->print_cr("lower bound check if: %s %d ", negated ? " negated" : "", lower_bound_iff->_idx);
+    if (TraceLoopPredicate) tty->print_cr("lower bound check if: %s %d ", negate ? " negated" : "", lower_bound_iff->_idx);
 
     // Test the upper bound
-    BoolNode* upper_bound_bol = rc_predicate(loop, lower_bound_proj, scale, offset, init, limit, stride, rng, true, overflow);
-    negated = false;
-    if (proj->_con != predicate_proj->_con) {
-      upper_bound_bol = new BoolNode(upper_bound_bol->in(1), upper_bound_bol->_test.negate());
-      register_new_node(upper_bound_bol, ctrl);
-      negated = true;
-    }
+    BoolNode* upper_bound_bol = rc_predicate(loop, lower_bound_proj, scale, offset, init, limit, stride, rng, true, overflow, negate);
+
     ProjNode* upper_bound_proj = create_new_if_for_predicate(predicate_proj, NULL, reason, overflow ? Op_If : iff->Opcode());
     assert(upper_bound_proj->in(0)->as_If()->in(0) == lower_bound_proj, "should dominate");
     IfNode* upper_bound_iff = upper_bound_proj->in(0)->as_If();
     _igvn.hash_delete(upper_bound_iff);
     upper_bound_iff->set_req(1, upper_bound_bol);
-    if (TraceLoopPredicate) tty->print_cr("upper bound check if: %s %d ", negated ? " negated" : "", lower_bound_iff->_idx);
+    if (TraceLoopPredicate) tty->print_cr("upper bound check if: %s %d ", negate ? " negated" : "", lower_bound_iff->_idx);
 
     // Fall through into rest of the clean up code which will move
     // any dependent nodes onto the upper bound test.
@@ -1370,10 +1360,10 @@ ProjNode* PhaseIdealLoop::insert_initial_skeleton_predicate(IfNode* iff, IdealLo
                                                             Node* rng, bool &overflow,
                                                             Deoptimization::DeoptReason reason) {
   // First predicate for the initial value on first loop iteration
-  assert(proj->_con && predicate_proj->_con, "not a range check?");
   Node* opaque_init = new OpaqueLoopInitNode(C, init);
   register_new_node(opaque_init, upper_bound_proj);
-  BoolNode* bol = rc_predicate(loop, upper_bound_proj, scale, offset, opaque_init, limit, stride, rng, (stride > 0) != (scale > 0), overflow);
+  bool negate = (proj->_con != predicate_proj->_con);
+  BoolNode* bol = rc_predicate(loop, upper_bound_proj, scale, offset, opaque_init, limit, stride, rng, (stride > 0) != (scale > 0), overflow, negate);
   Node* opaque_bol = new Opaque4Node(C, bol, _igvn.intcon(1)); // This will go away once loop opts are over
   C->add_skeleton_predicate_opaq(opaque_bol);
   register_new_node(opaque_bol, upper_bound_proj);
@@ -1391,7 +1381,7 @@ ProjNode* PhaseIdealLoop::insert_initial_skeleton_predicate(IfNode* iff, IdealLo
   register_new_node(max_value, new_proj);
   max_value = new AddINode(opaque_init, max_value);
   register_new_node(max_value, new_proj);
-  bol = rc_predicate(loop, new_proj, scale, offset, max_value, limit, stride, rng, (stride > 0) != (scale > 0), overflow);
+  bol = rc_predicate(loop, new_proj, scale, offset, max_value, limit, stride, rng, (stride > 0) != (scale > 0), overflow, negate);
   opaque_bol = new Opaque4Node(C, bol, _igvn.intcon(1));
   C->add_skeleton_predicate_opaq(opaque_bol);
   register_new_node(opaque_bol, new_proj);

src/hotspot/share/opto/loopTransform.cpp

@@ -2589,7 +2589,7 @@ Node* PhaseIdealLoop::add_range_check_predicate(IdealLoopTree* loop, CountedLoop
                                                 Node* predicate_proj, int scale_con, Node* offset,
                                                 Node* limit, jint stride_con, Node* value) {
   bool overflow = false;
-  BoolNode* bol = rc_predicate(loop, predicate_proj, scale_con, offset, value, NULL, stride_con, limit, (stride_con > 0) != (scale_con > 0), overflow);
+  BoolNode* bol = rc_predicate(loop, predicate_proj, scale_con, offset, value, NULL, stride_con, limit, (stride_con > 0) != (scale_con > 0), overflow, false);
   Node* opaque_bol = new Opaque4Node(C, bol, _igvn.intcon(1));
   register_new_node(opaque_bol, predicate_proj);
   IfNode* new_iff = NULL;

src/hotspot/share/opto/loopnode.hpp

@@ -1316,7 +1316,8 @@ class PhaseIdealLoop : public PhaseTransform {
   BoolNode* rc_predicate(IdealLoopTree *loop, Node* ctrl,
                          int scale, Node* offset,
                          Node* init, Node* limit, jint stride,
-                         Node* range, bool upper, bool &overflow);
+                         Node* range, bool upper, bool &overflow,
+                         bool negate);
 
   // Implementation of the loop predication to promote checks outside the loop
   bool loop_predication_impl(IdealLoopTree *loop);

test/hotspot/jtreg/compiler/loopopts/TestSkeletonPredicateNegation.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2021 THL A29 Limited, a Tencent company. All rights reserved.
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @bug 8273277
+ * @summary Skeleton predicates sometimes need to be negated
+ * @run main compiler.loopopts.TestSkeletonPredicateNegation
+ *
+ */
+
+package compiler.loopopts;
+
+public class TestSkeletonPredicateNegation {
+    public static int in0 = 2;
+
+    public static void main(String[] args) {
+        try {
+            TestSkeletonPredicateNegation instance = new TestSkeletonPredicateNegation();
+            for (int i = 0; i < 10000; ++i) {
+                instance.mainTest(args);
+            }
+        } catch (Exception ex) {
+            System.out.println(ex.getClass().getCanonicalName());
+        } catch (OutOfMemoryError e) {
+            System.out.println("OOM Error");
+        }
+    }
+
+    public void mainTest (String[] args){
+        long loa11[] = new long[1987];
+
+        for (long lo14 : loa11) {
+            TestSkeletonPredicateNegation.in0 = -128;
+            for (int i18 = 0; i18 < 52; i18++) {
+                try {
+                    loa11[TestSkeletonPredicateNegation.in0] %= 2275269548L;
+                    Math.ceil(1374905370.2785515599);
+                } catch (Exception a_e) {
+                    TestSkeletonPredicateNegation.in0--;
+                }
+            }
+        }
+    }
+}

test/hotspot/jtreg/vmTestbase/jit/t/t105/t105.java

@@ -23,15 +23,17 @@
 
 /*
  * @test
+ * @bug 8273277
  *
  * @summary converted from VM Testbase jit/t/t105.
  * VM Testbase keywords: [jit, quick]
  *
  * @library /vmTestbase
  *          /test/lib
  * @run main/othervm -XX:-OmitStackTraceInFastThrow jit.t.t105.t105
+ * @run main/othervm -XX:-OmitStackTraceInFastThrow -Xbatch -XX:Tier0BackedgeNotifyFreqLog=0 -XX:Tier2BackedgeNotifyFreqLog=0 -XX:Tier3BackedgeNotifyFreqLog=0 -XX:Tier2BackEdgeThreshold=1 -XX:Tier3BackEdgeThreshold=1 -XX:Tier4BackEdgeThreshold=1 jit.t.t105.t105
  *
- * This test must be run with ProfileTraps disabled to avoid preallocated
+ * This test must be run with OmitStackTraceInFastThrow disabled to avoid preallocated
  * exceptions. They don't have the detailed message that this test relies on.
  */