[MIPS] Adding validator for MIPS architecture.

src/trusted/validator_mips/testdata/test_jmp_imm.S

+# Copyright 2012 The Native Client Authors.  All rights reserved.
+# Use of this source code is governed by a BSD-style license that can
+# be found in the LICENSE file.
+# Copyright 2012 MIPS Technologies / RT-RK.
+
+# test cases for jmps/branches
+# there are several kinds of jmps/branches in regards to destination address
+# 1. jmps into 0-0x10000, null guard region, where everything is considered OK
+# 2. jmps into 0x10000-0x20000, trampoline code section, jmps need to be bundle aligned
+# 3. jmps into code section, jmps need to be bundle aligned
+# beside destination address we also check the position of jmp/b and link
+# instructions, which need to bundle offset +8
+
+
+.globl _start
+_start:
+.align 4
+.set noreorder
+
+bundle_b_to_0_0x1000:
+   b   _start - 0x10000    #destination addres is 0x10000 - OK
+    nop
+   b   _start - 0x1fff4    #destination addres is 0xc (null guard region)- OK
+    nop
+
+bundle_b_to_0x1000_0x20000:
+   b   _start - 0x10000    # ok - trampoline start
+    nop
+   b   _start - 0xfff4     # dest_addr = 0x1000c, error (middle of the trampoline)
+    nop
+
+bundle_b_to_code_area:
+   b   _start + 0x1000     # ok
+    nop
+   b   _start + 0x1004     # ok, not on pseudo instruction
+    nop
+   b   _start + 0x10       # ok
+    nop
+   b   end_of_code         # ok
+    nop
+
+bundle_j_to_0_0x1000:
+#all is allowed, b/c that is guard region
+   j       0x0
+    nop
+   j       0x4
+    nop
+
+bundle_j_trampoline_area:
+   j       0x10000
+    nop
+   jal     0x10004         # kProblemUnalignedJumpToTrampoline (not a trampoline start)
+    nop
+
+   nop
+   nop
+   jal     0x10010         # ok - not a trampoline start, but there is a halt, so ok.
+    nop
+
+   nop
+   nop
+   jal     0x10020         # ok
+    nop
+
+bundle_j_negative:
+   j       -0x4            # ok
+    nop
+   j       -0x10           # ok
+    nop
+
+bundle_1st:
+   and     $a0, $a0, $t7
+bundle_2nd:
+   sw      $ra, 24($a0)
+   addiu   $v0, $v0, 4
+   addiu   $v0, $v1, 0
+
+bl_check:
+   nop
+   nop
+   bal     bundle_1st      #ok
+    nop
+
+bundle_check_b_dest_addr:
+   b       bundle_1st      # ok
+    nop
+   b       bundle_2nd      # kProblemBranchSplitsPattern
+    nop
+
+   bal     0x10000         #error misaligned call
+    nop
+   jalx    0x3ffffff0      #error, forbidden instruction
+    nop
+
+   jal     0x10000         #error misaligned call
+    nop
+   jal     0x3fffff0       #ok
+    nop
+
+   b       bundle_2nd      # kProblemBranchSplitsPattern
+     nop
+     nop
+     nop
+
+end_of_code: