diff options
Diffstat (limited to 'vm/mterp/mips/OP_CHECK_CAST.S')
| -rw-r--r-- | vm/mterp/mips/OP_CHECK_CAST.S | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/vm/mterp/mips/OP_CHECK_CAST.S b/vm/mterp/mips/OP_CHECK_CAST.S new file mode 100644 index 000000000..f29a51f1e --- /dev/null +++ b/vm/mterp/mips/OP_CHECK_CAST.S @@ -0,0 +1,71 @@ +%verify "executed" +%verify "null object" +%verify "class cast exception thrown, with correct class name" +%verify "class cast exception not thrown on same class" +%verify "class cast exception not thrown on subclass" +%verify "class not resolved" +%verify "class already resolved" + /* + * Check to see if a cast from one class to another is allowed. + */ + # check-cast vAA, class /* BBBB */ + GET_OPA(a3) # a3 <- AA + FETCH(a2, 1) # a2 <- BBBB + GET_VREG(rOBJ, a3) # rOBJ <- object + LOAD_rSELF_methodClassDex(a0) # a0 <- pDvmDex + LOAD_base_offDvmDex_pResClasses(a0, a0) # a0 <- pDvmDex->pResClasses + # is object null? + beqz rOBJ, .L${opcode}_okay # null obj, cast always succeeds + LOAD_eas2(a1, a0, a2) # a1 <- resolved class + LOAD_base_offObject_clazz(a0, rOBJ) # a0 <- obj->clazz + # have we resolved this before? + beqz a1, .L${opcode}_resolve # not resolved, do it now +.L${opcode}_resolved: + # same class (trivial success)? + bne a0, a1, .L${opcode}_fullcheck # no, do full check +.L${opcode}_okay: + FETCH_ADVANCE_INST(2) # advance rPC, load rINST + GET_INST_OPCODE(t0) # extract opcode from rINST + GOTO_OPCODE(t0) # jump to next instruction + + /* + * Trivial test failed, need to perform full check. This is common. + * a0 holds obj->clazz + * a1 holds class resolved from BBBB + * rOBJ holds object + */ +.L${opcode}_fullcheck: + move rBIX,a1 # avoid ClassObject getting clobbered + JAL(dvmInstanceofNonTrivial) # v0 <- boolean result + # failed? + bnez v0, .L${opcode}_okay # no, success + b .L${opcode}_castfailure +%break + +.L${opcode}_castfailure: + # A cast has failed. We need to throw a ClassCastException with the + # class of the object that failed to be cast. + EXPORT_PC() # about to throw + LOAD_base_offObject_clazz(a0, rOBJ) # a0 <- obj->clazz + move a1,rBIX # r1<- desired class + JAL(dvmThrowClassCastException) + b common_exceptionThrown + + /* + * Resolution required. This is the least-likely path. + * + * a2 holds BBBB + * rOBJ holds object + */ +.L${opcode}_resolve: + EXPORT_PC() # resolve() could throw + LOAD_rSELF_method(a3) # a3 <- self->method + move a1, a2 # a1 <- BBBB + li a2, 0 # a2 <- false + LOAD_base_offMethod_clazz(a0, a3) # a0 <- method->clazz + JAL(dvmResolveClass) # v0 <- resolved ClassObject ptr + # got null? + beqz v0, common_exceptionThrown # yes, handle exception + move a1, v0 # a1 <- class resolved from BBB + LOAD_base_offObject_clazz(a0, rOBJ) # a0 <- obj->clazz + b .L${opcode}_resolved # pick up where we left off |