8159715: Fix for 8072422 is incorrect
Summary: Fixed several issues introduced by 8072422.
Reviewed-by: zmajo, kvn
--- a/hotspot/src/share/vm/opto/loopTransform.cpp Thu Jun 16 01:43:11 2016 +0300
+++ b/hotspot/src/share/vm/opto/loopTransform.cpp Mon Jun 20 09:32:44 2016 +0200
@@ -868,7 +868,7 @@
Node *bol = iff->in(1);
if (bol->req() != 2) continue; // dead constant test
if (!bol->is_Bool()) {
- assert(UseLoopPredicate && bol->Opcode() == Op_Conv2B, "predicate check only");
+ assert(bol->Opcode() == Op_Conv2B, "predicate check only");
continue;
}
if (bol->as_Bool()->_test._test == BoolTest::ne)
@@ -1760,14 +1760,6 @@
}
}
-//------------------------------dominates_backedge---------------------------------
-// Returns true if ctrl is executed on every complete iteration
-bool IdealLoopTree::dominates_backedge(Node* ctrl) {
- assert(ctrl->is_CFG(), "must be control");
- Node* backedge = _head->as_Loop()->in(LoopNode::LoopBackControl);
- return _phase->dom_lca_internal(ctrl, backedge) == ctrl;
-}
-
//------------------------------adjust_limit-----------------------------------
// Helper function for add_constraint().
Node* PhaseIdealLoop::adjust_limit(int stride_con, Node * scale, Node *offset, Node *rc_limit, Node *loop_limit, Node *pre_ctrl) {
@@ -2187,10 +2179,8 @@
if( b_test._test == BoolTest::lt ) { // Range checks always use lt
// The underflow and overflow limits: 0 <= scale*I+offset < limit
add_constraint( stride_con, scale_con, offset, zero, limit, pre_ctrl, &pre_limit, &main_limit );
- if (!conditional_rc) {
- // (0-offset)/scale could be outside of loop iterations range.
- conditional_rc = !loop->dominates_backedge(iff);
- }
+ // (0-offset)/scale could be outside of loop iterations range.
+ conditional_rc = true;
} else {
if (PrintOpto) {
tty->print_cr("missed RCE opportunity");
@@ -2221,12 +2211,10 @@
// Note: (MIN_INT+1 == -MAX_INT) is used instead of MIN_INT here
// to avoid problem with scale == -1: MIN_INT/(-1) == MIN_INT.
add_constraint( stride_con, scale_con, offset, mini, limit, pre_ctrl, &pre_limit, &main_limit );
- if (!conditional_rc) {
- // ((MIN_INT+1)-offset)/scale could be outside of loop iterations range.
- // Note: negative offset is replaced with 0 but (MIN_INT+1)/scale could
- // still be outside of loop range.
- conditional_rc = !loop->dominates_backedge(iff);
- }
+ // ((MIN_INT+1)-offset)/scale could be outside of loop iterations range.
+ // Note: negative offset is replaced with 0 but (MIN_INT+1)/scale could
+ // still be outside of loop range.
+ conditional_rc = true;
break;
default:
if (PrintOpto) {
--- a/hotspot/src/share/vm/opto/loopnode.cpp Thu Jun 16 01:43:11 2016 +0300
+++ b/hotspot/src/share/vm/opto/loopnode.cpp Mon Jun 20 09:32:44 2016 +0200
@@ -2225,9 +2225,7 @@
// Some parser-inserted loop predicates could never be used by loop
// predication or they were moved away from loop during some optimizations.
// For example, peeling. Eliminate them before next loop optimizations.
- if (UseLoopPredicate) {
- eliminate_useless_predicates();
- }
+ eliminate_useless_predicates();
#ifndef PRODUCT
C->verify_graph_edges();
--- a/hotspot/src/share/vm/opto/loopnode.hpp Thu Jun 16 01:43:11 2016 +0300
+++ b/hotspot/src/share/vm/opto/loopnode.hpp Mon Jun 20 09:32:44 2016 +0200
@@ -468,9 +468,6 @@
// Check for Node being a loop-breaking test
Node *is_loop_exit(Node *iff) const;
- // Returns true if ctrl is executed on every complete iteration
- bool dominates_backedge(Node* ctrl);
-
// Remove simplistic dead code from loop body
void DCE_loop_body();
--- a/hotspot/src/share/vm/opto/parse1.cpp Thu Jun 16 01:43:11 2016 +0300
+++ b/hotspot/src/share/vm/opto/parse1.cpp Mon Jun 20 09:32:44 2016 +0200
@@ -662,7 +662,7 @@
// (Note that dead locals do not get phis built, ever.)
ensure_phis_everywhere();
- if (block->is_SEL_head() && UseLoopPredicate) {
+ if (block->is_SEL_head()) {
// Add predicate to single entry (not irreducible) loop head.
assert(!block->has_merged_backedge(), "only entry paths should be merged for now");
// Need correct bci for predicate.