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diff src/cpu/x86/vm/c1_LIRAssembler_x86.cpp @ 2404:b40d4fa697bf

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6964776: c2 should ensure the polling page is reachable on 64 bit Summary: Materialize the pointer to the polling page in a register instead of using rip-relative addressing when the distance from the code cache is larger than disp32. Reviewed-by: never, kvn
author iveresov
date Sun, 27 Mar 2011 13:17:37 -0700
parents 1b4e6a5d98e0
children 09f96c3ff1ad
line wrap: on
line diff
--- a/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp	Sun Mar 27 00:00:14 2011 -0700
+++ b/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp	Sun Mar 27 13:17:37 2011 -0700
@@ -648,12 +648,13 @@
   AddressLiteral polling_page(os::get_polling_page() + (SafepointPollOffset % os::vm_page_size()),
                               relocInfo::poll_return_type);
 
-  // NOTE: the requires that the polling page be reachable else the reloc
-  // goes to the movq that loads the address and not the faulting instruction
-  // which breaks the signal handler code
-
-  __ test32(rax, polling_page);
-
+  if (Assembler::is_polling_page_far()) {
+    __ lea(rscratch1, polling_page);
+    __ relocate(relocInfo::poll_return_type);
+    __ testl(rax, Address(rscratch1, 0));
+  } else {
+    __ testl(rax, polling_page);
+  }
   __ ret(0);
 }
 
@@ -661,20 +662,17 @@
 int LIR_Assembler::safepoint_poll(LIR_Opr tmp, CodeEmitInfo* info) {
   AddressLiteral polling_page(os::get_polling_page() + (SafepointPollOffset % os::vm_page_size()),
                               relocInfo::poll_type);
-
-  if (info != NULL) {
+  guarantee(info != NULL, "Shouldn't be NULL");
+  int offset = __ offset();
+  if (Assembler::is_polling_page_far()) {
+    __ lea(rscratch1, polling_page);
+    offset = __ offset();
     add_debug_info_for_branch(info);
+    __ testl(rax, Address(rscratch1, 0));
   } else {
-    ShouldNotReachHere();
+    add_debug_info_for_branch(info);
+    __ testl(rax, polling_page);
   }
-
-  int offset = __ offset();
-
-  // NOTE: the requires that the polling page be reachable else the reloc
-  // goes to the movq that loads the address and not the faulting instruction
-  // which breaks the signal handler code
-
-  __ test32(rax, polling_page);
   return offset;
 }