[MIPS] Adding validator for MIPS architecture.

src/trusted/validator_mips/testdata/test_read_only_regs.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.
+
+#
+# Tests alteration of value stored in read-only registers.
+#
+
+.globl _start
+_start:
+.align 4
+.set noreorder
+.set STORE_MASK, $t7
+.set JUMP_MASK, $t6
+.set TLS_REG, $t8
+
+   # Testing instructions that alter t6 (JUMP_MASK).
+
+bundle_altering_t6:
+   addiu   JUMP_MASK, JUMP_MASK, 64       # Error, changing read-only register.
+   and     JUMP_MASK, JUMP_MASK, $a2      # Error, changing read-only register.
+   lui     JUMP_MASK, $f0                 # Error, changing read-only register.
+   clo     JUMP_MASK, $a2                 # Error, changing read-only register.
+   ins     JUMP_MASK, $s3, 2, 10          # Error, changing read-only register.
+   lui     JUMP_MASK, 0x1f                # Error, changing read-only register.
+   mfc1    JUMP_MASK, $f12                # Error, changing read-only register.
+   mfhc1   JUMP_MASK, $f10                # Error, changing read-only register.
+   mflo    JUMP_MASK                      # Error, changing read-only register.
+   movn    JUMP_MASK, $v0, $v1            # Error, changing read-only register.
+   movt    JUMP_MASK, $s4, $fcc4          # Error, changing read-only register.
+   mul     JUMP_MASK, $s0, $s1            # Error, changing read-only register.
+
+   # Testing instructions that alter t7 (STORE_MASK).
+
+bundle_altering_t7:
+   addiu   STORE_MASK, STORE_MASK, 64     # Error, changing read-only register.
+   and     STORE_MASK, STORE_MASK, $a2    # Error, changing read-only register.
+   lui     STORE_MASK, $f0                # Error, changing read-only register.
+   clo     STORE_MASK, $a2                # Error, changing read-only register.
+
+   # Testing instructions that alter t8 (TLS index).
+
+bundle_altering_t8:
+   lui     TLS_REG, 0x1f                  # Error, changing read-only register.
+   mfc1    TLS_REG, $f12                  # Error, changing read-only register.
+   mfhc1   TLS_REG, $f10                  # Error, changing read-only register.
+   mflo    TLS_REG                        # Error, changing read-only register.
+
+bundle_jalr_sp_t9:
+   nop
+   and     $t9, $t9, JUMP_MASK
+   jalr    STORE_MASK, $t9                # Error, changing read-only register.
+    nop                                   # Instr in delay slot is indented.
+
+   # Make sure $f14 is not interpreted
+   # as $t6 (14), when in fp instruction.
+
+bundle_fp_instr:
+   add.s   $f14, $f4, $f2
+   mov.d   $f14, $f0
+   neg.d   $f14, $f4
+   lwc1    $f14,24($sp)
+
+   # A few instructions where $t6/$t7
+   # is the first operand, but its value is not altered.
+
+bundle_t6_t7_not_altered:
+   mthi    JUMP_MASK                      # OK
+   mult    STORE_MASK, $t9                # OK
+   nop
+   nop
+
+end_of_code: