[WIP] ART Mterp: fix for hidden gc roots

To support moving gc, we must not hold onto any references solely
in registers across potential gc points.  This was happening during
returns, instance-of and check-cast.

[testing in progress]

Change-Id: I367750658c5716960737f0666e46800240fd392d

17 files changed, 117 insertions, 45 deletions

diff --git a/runtime/interpreter/mterp/arm/footer.S b/runtime/interpreter/mterp/arm/footer.S
index 617f572c0f..1dba856ecb 100644
--- a/runtime/interpreter/mterp/arm/footer.S
+++ b/runtime/interpreter/mterp/arm/footer.S
@@ -150,12 +150,8 @@ MterpExceptionReturn:
     b MterpDone
 MterpReturn:
     ldr     r2, [rFP, #OFF_FP_RESULT_REGISTER]
-    ldr     lr, [rSELF, #THREAD_FLAGS_OFFSET]
     str     r0, [r2]
     str     r1, [r2, #4]
-    mov     r0, rSELF
-    ands    lr, #(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST)
-    blne    MterpSuspendCheck                       @ (self)
     mov     r0, #1                                  @ signal return to caller.
 MterpDone:
     add     sp, sp, #4                              @ un-align 64
diff --git a/runtime/interpreter/mterp/arm/op_check_cast.S b/runtime/interpreter/mterp/arm/op_check_cast.S
index 3e3ac707c4..24eba45a69 100644
--- a/runtime/interpreter/mterp/arm/op_check_cast.S
+++ b/runtime/interpreter/mterp/arm/op_check_cast.S
@@ -5,10 +5,10 @@
     EXPORT_PC
     FETCH    r0, 1                      @ r0<- BBBB
     mov      r1, rINST, lsr #8          @ r1<- AA
-    GET_VREG r1, r1                     @ r1<- object
+    VREG_INDEX_TO_ADDR r1, r1           @ r1<- &object
     ldr      r2, [rFP, #OFF_FP_METHOD]  @ r2<- method
     mov      r3, rSELF                  @ r3<- self
-    bl       MterpCheckCast             @ (index, obj, method, self)
+    bl       MterpCheckCast             @ (index, &obj, method, self)
     PREFETCH_INST 2
     cmp      r0, #0
     bne      MterpPossibleException
diff --git a/runtime/interpreter/mterp/arm/op_instance_of.S b/runtime/interpreter/mterp/arm/op_instance_of.S
index e94108ca06..d76f0b09fe 100644
--- a/runtime/interpreter/mterp/arm/op_instance_of.S
+++ b/runtime/interpreter/mterp/arm/op_instance_of.S
@@ -8,12 +8,12 @@
     EXPORT_PC
     FETCH     r0, 1                     @ r0<- CCCC
     mov       r1, rINST, lsr #12        @ r1<- B
-    GET_VREG  r1, r1                    @ r1<- vB (object)
+    VREG_INDEX_TO_ADDR r1, r1           @ r1<- &object
     ldr       r2, [rFP, #OFF_FP_METHOD] @ r2<- method
     mov       r3, rSELF                 @ r3<- self
     mov       r9, rINST, lsr #8         @ r9<- A+
     and       r9, r9, #15               @ r9<- A
-    bl        MterpInstanceOf           @ (index, obj, method, self)
+    bl        MterpInstanceOf           @ (index, &obj, method, self)
     ldr       r1, [rSELF, #THREAD_EXCEPTION_OFFSET]
     PREFETCH_INST 2
     cmp       r1, #0                    @ exception pending?
diff --git a/runtime/interpreter/mterp/arm/op_return.S b/runtime/interpreter/mterp/arm/op_return.S
index a4ffd04ea6..1888373256 100644
--- a/runtime/interpreter/mterp/arm/op_return.S
+++ b/runtime/interpreter/mterp/arm/op_return.S
@@ -6,6 +6,10 @@
     /* op vAA */
     .extern MterpThreadFenceForConstructor
     bl      MterpThreadFenceForConstructor
+    ldr     lr, [rSELF, #THREAD_FLAGS_OFFSET]
+    mov     r0, rSELF
+    ands    lr, #(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST)
+    blne    MterpSuspendCheck                       @ (self)
     mov     r2, rINST, lsr #8           @ r2<- AA
     GET_VREG r0, r2                     @ r0<- vAA
     mov     r1, #0
diff --git a/runtime/interpreter/mterp/arm/op_return_void.S b/runtime/interpreter/mterp/arm/op_return_void.S
index f6dfd99309..cbea2bf6a0 100644
--- a/runtime/interpreter/mterp/arm/op_return_void.S
+++ b/runtime/interpreter/mterp/arm/op_return_void.S
@@ -1,5 +1,9 @@
     .extern MterpThreadFenceForConstructor
     bl      MterpThreadFenceForConstructor
+    ldr     lr, [rSELF, #THREAD_FLAGS_OFFSET]
+    mov     r0, rSELF
+    ands    lr, #(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST)
+    blne    MterpSuspendCheck                       @ (self)
     mov    r0, #0
     mov    r1, #0
     b      MterpReturn
diff --git a/runtime/interpreter/mterp/arm/op_return_void_no_barrier.S b/runtime/interpreter/mterp/arm/op_return_void_no_barrier.S
index 7322940a74..2dde7aeefc 100644
--- a/runtime/interpreter/mterp/arm/op_return_void_no_barrier.S
+++ b/runtime/interpreter/mterp/arm/op_return_void_no_barrier.S
@@ -1,3 +1,7 @@
+    ldr     lr, [rSELF, #THREAD_FLAGS_OFFSET]
+    mov     r0, rSELF
+    ands    lr, #(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST)
+    blne    MterpSuspendCheck                       @ (self)
     mov    r0, #0
     mov    r1, #0
     b      MterpReturn
diff --git a/runtime/interpreter/mterp/arm/op_return_wide.S b/runtime/interpreter/mterp/arm/op_return_wide.S
index 2881c87e58..cfab5301e5 100644
--- a/runtime/interpreter/mterp/arm/op_return_wide.S
+++ b/runtime/interpreter/mterp/arm/op_return_wide.S
@@ -4,6 +4,10 @@
     /* return-wide vAA */
     .extern MterpThreadFenceForConstructor
     bl      MterpThreadFenceForConstructor
+    ldr     lr, [rSELF, #THREAD_FLAGS_OFFSET]
+    mov     r0, rSELF
+    ands    lr, #(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST)
+    blne    MterpSuspendCheck                       @ (self)
     mov     r2, rINST, lsr #8           @ r2<- AA
     add     r2, rFP, r2, lsl #2         @ r2<- &fp[AA]
     ldmia   r2, {r0-r1}                 @ r0/r1 <- vAA/vAA+1
diff --git a/runtime/interpreter/mterp/mterp.cc b/runtime/interpreter/mterp/mterp.cc
index 9975458b85..0afd2765db 100644
--- a/runtime/interpreter/mterp/mterp.cc
+++ b/runtime/interpreter/mterp/mterp.cc
@@ -274,13 +274,15 @@ extern "C" bool MterpConstClass(uint32_t index, uint32_t tgt_vreg, ShadowFrame*
   return false;
 }
 
-extern "C" bool MterpCheckCast(uint32_t index, Object* obj, art::ArtMethod* method,
-                               Thread* self)
+extern "C" bool MterpCheckCast(uint32_t index, StackReference<mirror::Object>* vreg_addr,
+                               art::ArtMethod* method, Thread* self)
     SHARED_REQUIRES(Locks::mutator_lock_) {
   Class* c = ResolveVerifyAndClinit(index, method, self, false, false);
   if (UNLIKELY(c == nullptr)) {
     return true;
   }
+  // Must load obj from vreg following ResolveVerifyAndClinit due to moving gc.
+  Object* obj = vreg_addr->AsMirrorPtr();
   if (UNLIKELY(obj != nullptr && !obj->InstanceOf(c))) {
     ThrowClassCastException(c, obj->GetClass());
     return true;
@@ -288,13 +290,15 @@ extern "C" bool MterpCheckCast(uint32_t index, Object* obj, art::ArtMethod* meth
   return false;
 }
 
-extern "C" bool MterpInstanceOf(uint32_t index, Object* obj, art::ArtMethod* method,
-                                Thread* self)
+extern "C" bool MterpInstanceOf(uint32_t index, StackReference<mirror::Object>* vreg_addr,
+                                art::ArtMethod* method, Thread* self)
     SHARED_REQUIRES(Locks::mutator_lock_) {
   Class* c = ResolveVerifyAndClinit(index, method, self, false, false);
   if (UNLIKELY(c == nullptr)) {
     return false;  // Caller will check for pending exception.  Return value unimportant.
   }
+  // Must load obj from vreg following ResolveVerifyAndClinit due to moving gc.
+  Object* obj = vreg_addr->AsMirrorPtr();
   return (obj != nullptr) && obj->InstanceOf(c);
 }
 
@@ -505,8 +509,7 @@ extern "C" int artSet64IndirectStaticFromMterp(uint32_t field_idx, ArtMethod* re
                                                uint64_t* new_value, Thread* self)
     SHARED_REQUIRES(Locks::mutator_lock_) {
   ScopedQuickEntrypointChecks sqec(self);
-  ArtField* field = FindFieldFast(field_idx, referrer, StaticPrimitiveWrite,
-                                          sizeof(int64_t));
+  ArtField* field = FindFieldFast(field_idx, referrer, StaticPrimitiveWrite, sizeof(int64_t));
   if (LIKELY(field != nullptr)) {
     // Compiled code can't use transactional mode.
     field->Set64<false>(field->GetDeclaringClass(), *new_value);
@@ -524,8 +527,7 @@ extern "C" int artSet64IndirectStaticFromMterp(uint32_t field_idx, ArtMethod* re
 extern "C" int artSet8InstanceFromMterp(uint32_t field_idx, mirror::Object* obj, uint8_t new_value,
                                         ArtMethod* referrer)
     SHARED_REQUIRES(Locks::mutator_lock_) {
-  ArtField* field = FindFieldFast(field_idx, referrer, InstancePrimitiveWrite,
-                                          sizeof(int8_t));
+  ArtField* field = FindFieldFast(field_idx, referrer, InstancePrimitiveWrite, sizeof(int8_t));
   if (LIKELY(field != nullptr && obj != nullptr)) {
     Primitive::Type type = field->GetTypeAsPrimitiveType();
     if (type == Primitive::kPrimBoolean) {
@@ -582,7 +584,7 @@ extern "C" int artSet64InstanceFromMterp(uint32_t field_idx, mirror::Object* obj
 }
 
 extern "C" int artSetObjInstanceFromMterp(uint32_t field_idx, mirror::Object* obj,
-                                         mirror::Object* new_value, ArtMethod* referrer)
+                                          mirror::Object* new_value, ArtMethod* referrer)
     SHARED_REQUIRES(Locks::mutator_lock_) {
   ArtField* field = FindFieldFast(field_idx, referrer, InstanceObjectWrite,
                                           sizeof(mirror::HeapReference<mirror::Object>));
diff --git a/runtime/interpreter/mterp/out/mterp_arm.S b/runtime/interpreter/mterp/out/mterp_arm.S
index 9ae98a2bbe..78c784b773 100644
--- a/runtime/interpreter/mterp/out/mterp_arm.S
+++ b/runtime/interpreter/mterp/out/mterp_arm.S
@@ -599,6 +599,10 @@ artMterpAsmInstructionStart = .L_op_nop
 /* File: arm/op_return_void.S */
     .extern MterpThreadFenceForConstructor
     bl      MterpThreadFenceForConstructor
+    ldr     lr, [rSELF, #THREAD_FLAGS_OFFSET]
+    mov     r0, rSELF
+    ands    lr, #(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST)
+    blne    MterpSuspendCheck                       @ (self)
     mov    r0, #0
     mov    r1, #0
     b      MterpReturn
@@ -615,6 +619,10 @@ artMterpAsmInstructionStart = .L_op_nop
     /* op vAA */
     .extern MterpThreadFenceForConstructor
     bl      MterpThreadFenceForConstructor
+    ldr     lr, [rSELF, #THREAD_FLAGS_OFFSET]
+    mov     r0, rSELF
+    ands    lr, #(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST)
+    blne    MterpSuspendCheck                       @ (self)
     mov     r2, rINST, lsr #8           @ r2<- AA
     GET_VREG r0, r2                     @ r0<- vAA
     mov     r1, #0
@@ -630,6 +638,10 @@ artMterpAsmInstructionStart = .L_op_nop
     /* return-wide vAA */
     .extern MterpThreadFenceForConstructor
     bl      MterpThreadFenceForConstructor
+    ldr     lr, [rSELF, #THREAD_FLAGS_OFFSET]
+    mov     r0, rSELF
+    ands    lr, #(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST)
+    blne    MterpSuspendCheck                       @ (self)
     mov     r2, rINST, lsr #8           @ r2<- AA
     add     r2, rFP, r2, lsl #2         @ r2<- &fp[AA]
     ldmia   r2, {r0-r1}                 @ r0/r1 <- vAA/vAA+1
@@ -648,6 +660,10 @@ artMterpAsmInstructionStart = .L_op_nop
     /* op vAA */
     .extern MterpThreadFenceForConstructor
     bl      MterpThreadFenceForConstructor
+    ldr     lr, [rSELF, #THREAD_FLAGS_OFFSET]
+    mov     r0, rSELF
+    ands    lr, #(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST)
+    blne    MterpSuspendCheck                       @ (self)
     mov     r2, rINST, lsr #8           @ r2<- AA
     GET_VREG r0, r2                     @ r0<- vAA
     mov     r1, #0
@@ -878,10 +894,10 @@ artMterpAsmInstructionStart = .L_op_nop
     EXPORT_PC
     FETCH    r0, 1                      @ r0<- BBBB
     mov      r1, rINST, lsr #8          @ r1<- AA
-    GET_VREG r1, r1                     @ r1<- object
+    VREG_INDEX_TO_ADDR r1, r1           @ r1<- &object
     ldr      r2, [rFP, #OFF_FP_METHOD]  @ r2<- method
     mov      r3, rSELF                  @ r3<- self
-    bl       MterpCheckCast             @ (index, obj, method, self)
+    bl       MterpCheckCast             @ (index, &obj, method, self)
     PREFETCH_INST 2
     cmp      r0, #0
     bne      MterpPossibleException
@@ -903,12 +919,12 @@ artMterpAsmInstructionStart = .L_op_nop
     EXPORT_PC
     FETCH     r0, 1                     @ r0<- CCCC
     mov       r1, rINST, lsr #12        @ r1<- B
-    GET_VREG  r1, r1                    @ r1<- vB (object)
+    VREG_INDEX_TO_ADDR r1, r1           @ r1<- &object
     ldr       r2, [rFP, #OFF_FP_METHOD] @ r2<- method
     mov       r3, rSELF                 @ r3<- self
     mov       r9, rINST, lsr #8         @ r9<- A+
     and       r9, r9, #15               @ r9<- A
-    bl        MterpInstanceOf           @ (index, obj, method, self)
+    bl        MterpInstanceOf           @ (index, &obj, method, self)
     ldr       r1, [rSELF, #THREAD_EXCEPTION_OFFSET]
     PREFETCH_INST 2
     cmp       r1, #0                    @ exception pending?
@@ -3385,6 +3401,10 @@ artMterpAsmInstructionStart = .L_op_nop
     .balign 128
 .L_op_return_void_no_barrier: /* 0x73 */
 /* File: arm/op_return_void_no_barrier.S */
+    ldr     lr, [rSELF, #THREAD_FLAGS_OFFSET]
+    mov     r0, rSELF
+    ands    lr, #(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST)
+    blne    MterpSuspendCheck                       @ (self)
     mov    r0, #0
     mov    r1, #0
     b      MterpReturn
@@ -12183,12 +12203,8 @@ MterpExceptionReturn:
     b MterpDone
 MterpReturn:
     ldr     r2, [rFP, #OFF_FP_RESULT_REGISTER]
-    ldr     lr, [rSELF, #THREAD_FLAGS_OFFSET]
     str     r0, [r2]
     str     r1, [r2, #4]
-    mov     r0, rSELF
-    ands    lr, #(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST)
-    blne    MterpSuspendCheck                       @ (self)
     mov     r0, #1                                  @ signal return to caller.
 MterpDone:
     add     sp, sp, #4                              @ un-align 64
diff --git a/runtime/interpreter/mterp/out/mterp_x86.S b/runtime/interpreter/mterp/out/mterp_x86.S
index 923d502543..e2918dcfb2 100644
--- a/runtime/interpreter/mterp/out/mterp_x86.S
+++ b/runtime/interpreter/mterp/out/mterp_x86.S
@@ -575,6 +575,12 @@ artMterpAsmInstructionStart = .L_op_nop
 /* File: x86/op_return_void.S */
     .extern MterpThreadFenceForConstructor
     call    MterpThreadFenceForConstructor
+    movl    rSELF, %eax
+    testl   $(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST), THREAD_FLAGS_OFFSET(%eax)
+    jz      1f
+    movl    %eax, OUT_ARG0(%esp)
+    call    MterpSuspendCheck
+1:
     xorl    %eax, %eax
     xorl    %ecx, %ecx
     jmp     MterpReturn
@@ -591,6 +597,12 @@ artMterpAsmInstructionStart = .L_op_nop
     /* op vAA */
     .extern MterpThreadFenceForConstructor
     call    MterpThreadFenceForConstructor
+    movl    rSELF, %eax
+    testl   $(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST), THREAD_FLAGS_OFFSET(%eax)
+    jz      1f
+    movl    %eax, OUT_ARG0(%esp)
+    call    MterpSuspendCheck
+1:
     GET_VREG %eax rINST                     # eax <- vAA
     xorl    %ecx, %ecx
     jmp     MterpReturn
@@ -605,6 +617,12 @@ artMterpAsmInstructionStart = .L_op_nop
     /* return-wide vAA */
     .extern MterpThreadFenceForConstructor
     call    MterpThreadFenceForConstructor
+    movl    rSELF, %eax
+    testl   $(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST), THREAD_FLAGS_OFFSET(%eax)
+    jz      1f
+    movl    %eax, OUT_ARG0(%esp)
+    call    MterpSuspendCheck
+1:
     GET_VREG %eax rINST                     # eax <- v[AA+0]
     GET_VREG_HIGH %ecx rINST                # ecx <- v[AA+1]
     jmp     MterpReturn
@@ -622,6 +640,12 @@ artMterpAsmInstructionStart = .L_op_nop
     /* op vAA */
     .extern MterpThreadFenceForConstructor
     call    MterpThreadFenceForConstructor
+    movl    rSELF, %eax
+    testl   $(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST), THREAD_FLAGS_OFFSET(%eax)
+    jz      1f
+    movl    %eax, OUT_ARG0(%esp)
+    call    MterpSuspendCheck
+1:
     GET_VREG %eax rINST                     # eax <- vAA
     xorl    %ecx, %ecx
     jmp     MterpReturn
@@ -827,13 +851,13 @@ artMterpAsmInstructionStart = .L_op_nop
     EXPORT_PC
     movzwl  2(rPC), %eax                    # eax <- BBBB
     movl    %eax, OUT_ARG0(%esp)
-    GET_VREG %ecx rINST
+    leal    VREG_ADDRESS(rINST), %ecx
     movl    %ecx, OUT_ARG1(%esp)
     movl    OFF_FP_METHOD(rFP),%eax
     movl    %eax, OUT_ARG2(%esp)
     movl    rSELF, %ecx
     movl    %ecx, OUT_ARG3(%esp)
-    call    MterpCheckCast                  # (index, obj, method, self)
+    call    MterpCheckCast                  # (index, &obj, method, self)
     REFRESH_IBASE
     testl   %eax, %eax
     jnz     MterpPossibleException
@@ -855,13 +879,13 @@ artMterpAsmInstructionStart = .L_op_nop
     movl    %eax, OUT_ARG0(%esp)
     movl    rINST, %eax                     # eax <- BA
     sarl    $4, %eax                       # eax <- B
-    GET_VREG %ecx %eax                      # Get object
+    leal    VREG_ADDRESS(%eax), %ecx        # Get object address
     movl    %ecx, OUT_ARG1(%esp)
     movl    OFF_FP_METHOD(rFP),%eax
     movl    %eax, OUT_ARG2(%esp)
     movl    rSELF, %ecx
     movl    %ecx, OUT_ARG3(%esp)
-    call    MterpInstanceOf                 # (index, obj, method, self)
+    call    MterpInstanceOf                 # (index, &obj, method, self)
     movl    rSELF, %ecx
     REFRESH_IBASE_FROM_SELF %ecx
     cmpl    $0, THREAD_EXCEPTION_OFFSET(%ecx)
@@ -3145,6 +3169,12 @@ artMterpAsmInstructionStart = .L_op_nop
     .balign 128
 .L_op_return_void_no_barrier: /* 0x73 */
 /* File: x86/op_return_void_no_barrier.S */
+    movl    rSELF, %eax
+    testl   $(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST), THREAD_FLAGS_OFFSET(%eax)
+    jz      1f
+    movl    %eax, OUT_ARG0(%esp)
+    call    MterpSuspendCheck
+1:
     xorl    %eax, %eax
     xorl    %ecx, %ecx
     jmp     MterpReturn
@@ -12921,12 +12951,6 @@ MterpReturn:
     movl    OFF_FP_RESULT_REGISTER(rFP), %edx
     movl    %eax, (%edx)
     movl    %ecx, 4(%edx)
-    movl    rSELF, %eax
-    testl   $(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST), THREAD_FLAGS_OFFSET(%eax)
-    jz      1f
-    movl    %eax, OUT_ARG0(%esp)
-    call    MterpSuspendCheck
-1:
     mov     $1, %eax
 MterpDone:
     /* Restore callee save register */
diff --git a/runtime/interpreter/mterp/x86/footer.S b/runtime/interpreter/mterp/x86/footer.S
index 8f79b37681..a2a36c4f64 100644
--- a/runtime/interpreter/mterp/x86/footer.S
+++ b/runtime/interpreter/mterp/x86/footer.S
@@ -169,12 +169,6 @@ MterpReturn:
     movl    OFF_FP_RESULT_REGISTER(rFP), %edx
     movl    %eax, (%edx)
     movl    %ecx, 4(%edx)
-    movl    rSELF, %eax
-    testl   $$(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST), THREAD_FLAGS_OFFSET(%eax)
-    jz      1f
-    movl    %eax, OUT_ARG0(%esp)
-    call    MterpSuspendCheck
-1:
     mov     $$1, %eax
 MterpDone:
     /* Restore callee save register */
diff --git a/runtime/interpreter/mterp/x86/op_check_cast.S b/runtime/interpreter/mterp/x86/op_check_cast.S
index 3d85f5e404..018432a92a 100644
--- a/runtime/interpreter/mterp/x86/op_check_cast.S
+++ b/runtime/interpreter/mterp/x86/op_check_cast.S
@@ -5,13 +5,13 @@
     EXPORT_PC
     movzwl  2(rPC), %eax                    # eax <- BBBB
     movl    %eax, OUT_ARG0(%esp)
-    GET_VREG %ecx rINST
+    leal    VREG_ADDRESS(rINST), %ecx
     movl    %ecx, OUT_ARG1(%esp)
     movl    OFF_FP_METHOD(rFP),%eax
     movl    %eax, OUT_ARG2(%esp)
     movl    rSELF, %ecx
     movl    %ecx, OUT_ARG3(%esp)
-    call    MterpCheckCast                  # (index, obj, method, self)
+    call    MterpCheckCast                  # (index, &obj, method, self)
     REFRESH_IBASE
     testl   %eax, %eax
     jnz     MterpPossibleException
diff --git a/runtime/interpreter/mterp/x86/op_instance_of.S b/runtime/interpreter/mterp/x86/op_instance_of.S
index cfbd4a0353..c9bfba5c36 100644
--- a/runtime/interpreter/mterp/x86/op_instance_of.S
+++ b/runtime/interpreter/mterp/x86/op_instance_of.S
@@ -10,13 +10,13 @@
     movl    %eax, OUT_ARG0(%esp)
     movl    rINST, %eax                     # eax <- BA
     sarl    $$4, %eax                       # eax <- B
-    GET_VREG %ecx %eax                      # Get object
+    leal    VREG_ADDRESS(%eax), %ecx        # Get object address
     movl    %ecx, OUT_ARG1(%esp)
     movl    OFF_FP_METHOD(rFP),%eax
     movl    %eax, OUT_ARG2(%esp)
     movl    rSELF, %ecx
     movl    %ecx, OUT_ARG3(%esp)
-    call    MterpInstanceOf                 # (index, obj, method, self)
+    call    MterpInstanceOf                 # (index, &obj, method, self)
     movl    rSELF, %ecx
     REFRESH_IBASE_FROM_SELF %ecx
     cmpl    $$0, THREAD_EXCEPTION_OFFSET(%ecx)
diff --git a/runtime/interpreter/mterp/x86/op_return.S b/runtime/interpreter/mterp/x86/op_return.S
index 1658322e52..183b3bfdd5 100644
--- a/runtime/interpreter/mterp/x86/op_return.S
+++ b/runtime/interpreter/mterp/x86/op_return.S
@@ -6,6 +6,12 @@
     /* op vAA */
     .extern MterpThreadFenceForConstructor
     call    MterpThreadFenceForConstructor
+    movl    rSELF, %eax
+    testl   $$(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST), THREAD_FLAGS_OFFSET(%eax)
+    jz      1f
+    movl    %eax, OUT_ARG0(%esp)
+    call    MterpSuspendCheck
+1:
     GET_VREG %eax rINST                     # eax <- vAA
     xorl    %ecx, %ecx
     jmp     MterpReturn
diff --git a/runtime/interpreter/mterp/x86/op_return_void.S b/runtime/interpreter/mterp/x86/op_return_void.S
index b74446e1c2..f3e24c7990 100644
--- a/runtime/interpreter/mterp/x86/op_return_void.S
+++ b/runtime/interpreter/mterp/x86/op_return_void.S
@@ -1,5 +1,11 @@
     .extern MterpThreadFenceForConstructor
     call    MterpThreadFenceForConstructor
+    movl    rSELF, %eax
+    testl   $$(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST), THREAD_FLAGS_OFFSET(%eax)
+    jz      1f
+    movl    %eax, OUT_ARG0(%esp)
+    call    MterpSuspendCheck
+1:
     xorl    %eax, %eax
     xorl    %ecx, %ecx
     jmp     MterpReturn
diff --git a/runtime/interpreter/mterp/x86/op_return_void_no_barrier.S b/runtime/interpreter/mterp/x86/op_return_void_no_barrier.S
index abc7c4d745..add4e203fb 100644
--- a/runtime/interpreter/mterp/x86/op_return_void_no_barrier.S
+++ b/runtime/interpreter/mterp/x86/op_return_void_no_barrier.S
@@ -1,3 +1,9 @@
+    movl    rSELF, %eax
+    testl   $$(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST), THREAD_FLAGS_OFFSET(%eax)
+    jz      1f
+    movl    %eax, OUT_ARG0(%esp)
+    call    MterpSuspendCheck
+1:
     xorl    %eax, %eax
     xorl    %ecx, %ecx
     jmp     MterpReturn
diff --git a/runtime/interpreter/mterp/x86/op_return_wide.S b/runtime/interpreter/mterp/x86/op_return_wide.S
index 00effd66cd..34a3380326 100644
--- a/runtime/interpreter/mterp/x86/op_return_wide.S
+++ b/runtime/interpreter/mterp/x86/op_return_wide.S
@@ -4,6 +4,12 @@
     /* return-wide vAA */
     .extern MterpThreadFenceForConstructor
     call    MterpThreadFenceForConstructor
+    movl    rSELF, %eax
+    testl   $$(THREAD_SUSPEND_REQUEST | THREAD_CHECKPOINT_REQUEST), THREAD_FLAGS_OFFSET(%eax)
+    jz      1f
+    movl    %eax, OUT_ARG0(%esp)
+    call    MterpSuspendCheck
+1:
     GET_VREG %eax rINST                     # eax <- v[AA+0]
     GET_VREG_HIGH %ecx rINST                # ecx <- v[AA+1]
     jmp     MterpReturn