re PR middle-end/44765 (gen_rtx_REG can make out-of-bounds access for INVALID_REGNUM)

	PR middle-end/44765
	* emit-rtl.c (gen_rtx_REG): Before using PIC_OFFSET_TABLE_REGNUM
	as an index, check it is not INVALID_REGNUM.

From-SVN: r166307

gcc/ChangeLog

+2010-10-04  Joern Rennecke  <amylaar@spamcop.net>
+
+	PR middle-end/44765
+	* emit-rtl.c (gen_rtx_REG): Before using PIC_OFFSET_TABLE_REGNUM
+	as an index, check it is not INVALID_REGNUM.
+
 2010-11-04  Ira Rosen  <irar@il.ibm.com>
 
 	PR tree-optimization/46213

gcc/emit-rtl.c

@@ -603,6 +603,7 @@ gen_rtx_REG (enum machine_mode mode, unsigned int regno)
 	return return_address_pointer_rtx;
 #endif
       if (regno == (unsigned) PIC_OFFSET_TABLE_REGNUM
+	  && PIC_OFFSET_TABLE_REGNUM != INVALID_REGNUM
 	  && fixed_regs[PIC_OFFSET_TABLE_REGNUM])
 	return pic_offset_table_rtx;
       if (regno == STACK_POINTER_REGNUM)