java runtime: add simple version of instanceof

[mate.git] / Mate / X86CodeGen.hs

diff --git a/Mate/X86CodeGen.hs b/Mate/X86CodeGen.hs
index 6def8de41da1f5d8bafee84acce33cd413297dda..448c966e19d5f41e51003e39685ac0a21f7e2601 100644 (file)
--- a/Mate/X86CodeGen.hs
+++ b/Mate/X86CodeGen.hs
@@ -104,15 +104,14 @@ emitFromBB cls method = do
       calladdr <- getCurrentOffset
       newNamedLabel (show l) >>= defineLabel
       -- causes SIGILL. in the signal handler we patch it to the acutal call.
-      -- place a nop at the end, therefore the disasm doesn't screw up
-      emit32 (0xffff9090 :: Word32) >> emit8 (0x90 :: Word8)
+      -- place two nop's at the end, therefore the disasm doesn't screw up
+      emit32 (0x9090ffff :: Word32) >> emit8 (0x90 :: Word8)
       -- discard arguments on stack
       let argcnt = ((if hasThis then 1 else 0) + methodGetArgsCount (methodNameTypeByIdx cls cpidx)) * ptrSize
       when (argcnt > 0) (add esp argcnt)
       -- push result on stack if method has a return value
       when (methodHaveReturnValue cls cpidx) (push eax)
-      -- +2 is for correcting eip in trap context
-      return $ Just (calladdr + 2, StaticMethod l)
+      return $ Just (calladdr, StaticMethod l)
 
     invokeEpilog :: Word16 -> Word32 -> (Bool -> TrapCause) -> CodeGen e s (Maybe (Word32, TrapCause))
     invokeEpilog cpidx offset trapcause = do
@@ -174,6 +173,17 @@ emitFromBB cls method = do
       mov eax (Addr 0x00000000) -- it's a trap
       push eax
       return $ Just (trapaddr, StaticField $ buildStaticFieldID cls cpidx)
+    emit' (INSTANCEOF cpidx) = do
+      pop eax
+      mov eax (Disp 0, eax) -- mtable of objectref
+      trapaddr <- getCurrentOffset
+      -- place something like `mov edx $mtable_of_objref' instead
+      emit32 (0x9090ffff :: Word32) >> emit8 (0x90 :: Word8)
+      cmp eax edx
+      sete al
+      movzxb eax al
+      push eax
+      return $ Just (trapaddr, InstanceOf $ buildClassID cls cpidx)
     emit' insn = emit insn >> return Nothing
 
     emit :: J.Instruction -> CodeGen e s ()
@@ -237,10 +247,6 @@ emitFromBB cls method = do
       mtable <- liftIO $ getMethodTable objname
       mov (Disp 0, eax) mtable
     emit (CHECKCAST _) = nop -- TODO(bernhard): ...
-    -- TODO(bernhard): ...
-    emit (INSTANCEOF _) = do
-      pop eax
-      push (1 :: Word32)
     emit ATHROW = -- TODO(bernhard): ...
         emit32 (0xffffffff :: Word32)
     emit I2C = do