src/hotspot/cpu/x86/x86_32.ad

rev 48494 : 8195112: x86 (32 bit): implementation for Thread-local handshakes
Reviewed-by:

@@ -315,11 +315,11 @@
 }
 
 // Indicate if the safepoint node needs the polling page as an input.
 // Since x86 does have absolute addressing, it doesn't.
 bool SafePointNode::needs_polling_address_input() {
-  return false;
+  return SafepointMechanism::uses_thread_local_poll();
 }
 
 //
 // Compute padding required for nodes which need alignment
 //

@@ -704,38 +704,29 @@
   if (StackReservedPages > 0 && C->has_reserved_stack_access()) {
     __ reserved_stack_check();
   }
 
   if (do_polling() && C->is_method_compilation()) {
+    if (SafepointMechanism::uses_thread_local_poll()) {
+      Register pollReg = as_Register(EBX_enc);
+      MacroAssembler masm(&cbuf);
+      masm.get_thread(pollReg);
+      masm.movl(pollReg, Address(pollReg, in_bytes(Thread::polling_page_offset())));
+      masm.relocate(relocInfo::poll_return_type);
+      masm.testl(rax, Address(pollReg, 0));
+    } else {
     cbuf.relocate(cbuf.insts_end(), relocInfo::poll_return_type, 0);
     emit_opcode(cbuf,0x85);
     emit_rm(cbuf, 0x0, EAX_enc, 0x5); // EAX
     emit_d32(cbuf, (intptr_t)os::get_polling_page());
   }
+  }
 }
 
 uint MachEpilogNode::size(PhaseRegAlloc *ra_) const {
-  Compile *C = ra_->C;
-  // If method set FPU control word, restore to standard control word
-  int size = C->in_24_bit_fp_mode() ? 6 : 0;
-  if (C->max_vector_size() > 16) size += 3; // vzeroupper
-  if (do_polling() && C->is_method_compilation()) size += 6;
-
-  int framesize = C->frame_size_in_bytes();
-  assert((framesize & (StackAlignmentInBytes-1)) == 0, "frame size not aligned");
-  // Remove two words for return addr and rbp,
-  framesize -= 2*wordSize;
-
-  size++; // popl rbp,
-
-  if (framesize >= 128) {
-    size += 6;
-  } else {
-    size += framesize ? 3 : 0;
-  }
-  size += 64; // added to support ReservedStackAccess
-  return size;
+  return MachNode::size(ra_); // too many variables; just compute it
+                              // the hard way
 }
 
 int MachEpilogNode::reloc() const {
   return 0; // a large enough number
 }

@@ -13334,10 +13325,11 @@
 
 
 // ============================================================================
 // Safepoint Instruction
 instruct safePoint_poll(eFlagsReg cr) %{
+  predicate(SafepointMechanism::uses_global_page_poll());
   match(SafePoint);
   effect(KILL cr);
 
   // TODO-FIXME: we currently poll at offset 0 of the safepoint polling page.
   // On SPARC that might be acceptable as we can generate the address with

@@ -13352,10 +13344,29 @@
   size(6) ;
   ins_encode( Safepoint_Poll() );
   ins_pipe( ialu_reg_mem );
 %}
 
+instruct safePoint_poll_tls(eFlagsReg cr, eRegP_no_EBP poll) %{
+  predicate(SafepointMechanism::uses_thread_local_poll());
+  match(SafePoint poll);
+  effect(KILL cr, USE poll);
+
+  format %{ "TSTL   #EAX,[$poll]\t! Safepoint: poll for GC" %}
+  ins_cost(125);
+  // EBP would need size(3)
+  size(2); /* setting an explicit size will cause debug builds to assert if size is incorrect */
+  ins_encode %{
+    __ relocate(relocInfo::poll_type);
+    address pre_pc = __ pc();
+    __ testl(rax, Address($poll$$Register, 0));
+    address post_pc = __ pc();
+    guarantee(pre_pc[0] == 0x85, "must emit test-ax [reg]");
+  %}
+  ins_pipe(ialu_reg_mem);
+%}
+
 
 // ============================================================================
 // This name is KNOWN by the ADLC and cannot be changed.
 // The ADLC forces a 'TypeRawPtr::BOTTOM' output type
 // for this guy.