8021898: Broken JIT compiler optimization for loop unswitching

Fix method clone_projs() to clone all related MachProj nodes.

Reviewed-by: roland, adlertz

hotspot/src/share/vm/opto/chaitin.cpp

@@ -287,21 +287,26 @@ void PhaseChaitin::new_lrg(const Node *x, uint lrg) {
 }
 
 
-bool PhaseChaitin::clone_projs_shared(Block *b, uint idx, Node *con, Node *copy, uint max_lrg_id) {
-  Block* bcon = _cfg.get_block_for_node(con);
-  uint cindex = bcon->find_node(con);
-  Node *con_next = bcon->_nodes[cindex+1];
-  if (con_next->in(0) != con || !con_next->is_MachProj()) {
-    return false;               // No MachProj's follow
+int PhaseChaitin::clone_projs(Block* b, uint idx, Node* orig, Node* copy, uint& max_lrg_id) {
+  assert(b->find_node(copy) == (idx - 1), "incorrect insert index for copy kill projections");
+  DEBUG_ONLY( Block* borig = _cfg.get_block_for_node(orig); )
+  int found_projs = 0;
+  uint cnt = orig->outcnt();
+  for (uint i = 0; i < cnt; i++) {
+    Node* proj = orig->raw_out(i);
+    if (proj->is_MachProj()) {
+      assert(proj->outcnt() == 0, "only kill projections are expected here");
+      assert(_cfg.get_block_for_node(proj) == borig, "incorrect block for kill projections");
+      found_projs++;
+      // Copy kill projections after the cloned node
+      Node* kills = proj->clone();
+      kills->set_req(0, copy);
+      b->_nodes.insert(idx++, kills);
+      _cfg.map_node_to_block(kills, b);
+      new_lrg(kills, max_lrg_id++);
+    }
   }
-
-  // Copy kills after the cloned constant
-  Node *kills = con_next->clone();
-  kills->set_req(0, copy);
-  b->_nodes.insert(idx, kills);
-  _cfg.map_node_to_block(kills, b);
-  new_lrg(kills, max_lrg_id);
-  return true;
+  return found_projs;
 }
 
 // Renumber the live ranges to compact them.  Makes the IFG smaller.

hotspot/src/share/vm/opto/chaitin.hpp

@@ -412,33 +412,22 @@ class PhaseChaitin : public PhaseRegAlloc {
   uint split_DEF( Node *def, Block *b, int loc, uint max, Node **Reachblock, Node **debug_defs, GrowableArray<uint> splits, int slidx );
   uint split_USE( Node *def, Block *b, Node *use, uint useidx, uint max, bool def_down, bool cisc_sp, GrowableArray<uint> splits, int slidx );
 
-  bool clone_projs(Block *b, uint idx, Node *con, Node *copy, LiveRangeMap &lrg_map) {
-    bool found_projs = clone_projs_shared(b, idx, con, copy, lrg_map.max_lrg_id());
-
-    if(found_projs) {
-      uint max_lrg_id = lrg_map.max_lrg_id();
-      lrg_map.set_max_lrg_id(max_lrg_id + 1);
-    }
-
-    return found_projs;
-  }
-
   //------------------------------clone_projs------------------------------------
   // After cloning some rematerialized instruction, clone any MachProj's that
   // follow it.  Example: Intel zero is XOR, kills flags.  Sparc FP constants
   // use G3 as an address temp.
-  bool clone_projs(Block *b, uint idx, Node *con, Node *copy, uint &max_lrg_id) {
-    bool found_projs = clone_projs_shared(b, idx, con, copy, max_lrg_id);
+  int clone_projs(Block* b, uint idx, Node* orig, Node* copy, uint& max_lrg_id);
 
-    if(found_projs) {
-      max_lrg_id++;
+  int clone_projs(Block* b, uint idx, Node* orig, Node* copy, LiveRangeMap& lrg_map) {
+    uint max_lrg_id = lrg_map.max_lrg_id();
+    int found_projs = clone_projs(b, idx, orig, copy, max_lrg_id);
+    if (found_projs > 0) {
+      // max_lrg_id is updated during call above
+      lrg_map.set_max_lrg_id(max_lrg_id);
     }
-
     return found_projs;
   }
 
-  bool clone_projs_shared(Block *b, uint idx, Node *con, Node *copy, uint max_lrg_id);
-
   Node *split_Rematerialize(Node *def, Block *b, uint insidx, uint &maxlrg, GrowableArray<uint> splits,
                             int slidx, uint *lrg2reach, Node **Reachblock, bool walkThru);
   // True if lidx is used before any real register is def'd in the block

hotspot/src/share/vm/opto/coalesce.cpp

@@ -322,9 +322,7 @@ void PhaseAggressiveCoalesce::insert_copies( Matcher &matcher ) {
               copy = m->clone();
               // Insert the copy in the basic block, just before us
               b->_nodes.insert(l++, copy);
-              if(_phc.clone_projs(b, l, m, copy, _phc._lrg_map)) {
-                l++;
-              }
+              l += _phc.clone_projs(b, l, m, copy, _phc._lrg_map);
             } else {
               const RegMask *rm = C->matcher()->idealreg2spillmask[m->ideal_reg()];
               copy = new (C) MachSpillCopyNode(m, *rm, *rm);

hotspot/src/share/vm/opto/reg_split.cpp

@@ -397,10 +397,15 @@ Node *PhaseChaitin::split_Rematerialize( Node *def, Block *b, uint insidx, uint
 #endif
   // See if the cloned def kills any flags, and copy those kills as well
   uint i = insidx+1;
-  if( clone_projs( b, i, def, spill, maxlrg) ) {
+  int found_projs = clone_projs( b, i, def, spill, maxlrg);
+  if (found_projs > 0) {
     // Adjust the point where we go hi-pressure
-    if( i <= b->_ihrp_index ) b->_ihrp_index++;
-    if( i <= b->_fhrp_index ) b->_fhrp_index++;
+    if (i <= b->_ihrp_index) {
+      b->_ihrp_index += found_projs;
+    }
+    if (i <= b->_fhrp_index) {
+      b->_fhrp_index += found_projs;
+    }
   }
 
   return spill;

hotspot/src/share/vm/runtime/frame.cpp

@@ -23,6 +23,7 @@
  */
 
 #include "precompiled.hpp"
+#include "compiler/abstractCompiler.hpp"
 #include "compiler/disassembler.hpp"
 #include "gc_interface/collectedHeap.inline.hpp"
 #include "interpreter/interpreter.hpp"
@@ -559,7 +560,7 @@ void frame::print_value_on(outputStream* st, JavaThread *thread) const {
 
   st->print("%s frame (sp=" INTPTR_FORMAT " unextended sp=" INTPTR_FORMAT, print_name(), sp(), unextended_sp());
   if (sp() != NULL)
-    st->print(", fp=" INTPTR_FORMAT ", pc=" INTPTR_FORMAT, fp(), pc());
+    st->print(", fp=" INTPTR_FORMAT ", real_fp=" INTPTR_FORMAT ", pc=" INTPTR_FORMAT, fp(), real_fp(), pc());
 
   if (StubRoutines::contains(pc())) {
     st->print_cr(")");
@@ -720,11 +721,14 @@ void frame::print_on_error(outputStream* st, char* buf, int buflen, bool verbose
     } else if (_cb->is_buffer_blob()) {
       st->print("v  ~BufferBlob::%s", ((BufferBlob *)_cb)->name());
     } else if (_cb->is_nmethod()) {
-      Method* m = ((nmethod *)_cb)->method();
+      nmethod* nm = (nmethod*)_cb;
+      Method* m = nm->method();
       if (m != NULL) {
         m->name_and_sig_as_C_string(buf, buflen);
-        st->print("J  %s @ " PTR_FORMAT " [" PTR_FORMAT "+" SIZE_FORMAT "]",
-                  buf, _pc, _cb->code_begin(), _pc - _cb->code_begin());
+        st->print("J %d%s %s %s (%d bytes) @ " PTR_FORMAT " [" PTR_FORMAT "+0x%x]",
+                  nm->compile_id(), (nm->is_osr_method() ? "%" : ""),
+                  ((nm->compiler() != NULL) ? nm->compiler()->name() : ""),
+                  buf, m->code_size(), _pc, _cb->code_begin(), _pc - _cb->code_begin());
       } else {
         st->print("J  " PTR_FORMAT, pc());
       }

hotspot/src/share/vm/utilities/vmError.cpp

@@ -586,6 +586,13 @@ void VMError::report(outputStream* st) {
           while (count++ < StackPrintLimit) {
              fr.print_on_error(st, buf, sizeof(buf));
              st->cr();
+             // Compiled code may use EBP register on x86 so it looks like
+             // non-walkable C frame. Use frame.sender() for java frames.
+             if (_thread && _thread->is_Java_thread() && fr.is_java_frame()) {
+               RegisterMap map((JavaThread*)_thread, false); // No update
+               fr = fr.sender(&map);
+               continue;
+             }
              if (os::is_first_C_frame(&fr)) break;
              fr = os::get_sender_for_C_frame(&fr);
           }