# HG changeset patch
# User Jin
# Date 1462482275 14400
# Node ID ef5b28e8d433b0b76f2adf9243ad3152fa385382
# Parent  26621fe12c4880a3d4a49025053ff89e7f084f4f
TemplateTable::fast_xaccess(): fix unaligned lhu

BCP and offset may both be unaligned.
Two LBU are required.

public class List {
    public List next;

    public void insert() {
        List p = new List();
        p.next = this.next;
    }

    public static void main(String[] args) throws Exception {
        List th = new List();
        while(true)
            th.insert();
    }
}

Effect:
- -Xint: 0 unaligned access

diff -r 26621fe12c48 -r ef5b28e8d433 src/cpu/mips/vm/assembler_mips.cpp
--- a/src/cpu/mips/vm/assembler_mips.cpp	Thu May 05 14:53:07 2016 -0400
+++ b/src/cpu/mips/vm/assembler_mips.cpp	Thu May 05 17:04:35 2016 -0400
@@ -3277,22 +3277,17 @@
 
 void MacroAssembler::load_two_bytes_from_at_bcp(Register reg, Register tmp, int offset)
 {
-
-  if(offset & 1){
-    lbu(reg, BCP, offset+1); 
-    lbu(tmp, BCP, offset);
+  /* 2016/5/6 Jin: the runtime address of BCP may be unaligned.
+   *   Refer to the SPARC implementation. */
+  lbu(reg, BCP, offset+1); 
+  lbu(tmp, BCP, offset);
 #ifdef _LP64
-//FIXME aoqi. indexbyte1 << 8 | indexbyte2?
-    //dsll(tmp, tmp, 8);
-    dsll(reg, reg, 8);
-    daddu(reg, tmp, reg);
+  dsll(reg, reg, 8);
+  daddu(reg, tmp, reg);
 #else
-    sll(reg, reg, 8);
-    addu(reg, tmp, reg);
+  sll(reg, reg, 8);
+  addu(reg, tmp, reg);
 #endif
-  }
-  else
-    lhu(reg, BCP, offset);
 }
 
 void MacroAssembler::store_two_byts_to_at_bcp(Register reg, Register tmp, int offset)