new insn: fix wrong behaviour on lazy class init

[mate.git] / Mate / X86CodeGen.hs

diff --git a/Mate/X86CodeGen.hs b/Mate/X86CodeGen.hs
index 6def8de41da1f5d8bafee84acce33cd413297dda..ffdc83d8b2021d6f7e8639c38fc6257feb9b4072 100644 (file)
--- a/Mate/X86CodeGen.hs
+++ b/Mate/X86CodeGen.hs
@@ -91,6 +91,13 @@ emitFromBB cls method = do
     -- TODO(bernhard): implement `emit' as function which accepts a list of
     --                 instructions, so we can use patterns for optimizations
     where
+    forceRegDump :: CodeGen e s ()
+    forceRegDump = do
+      push esi
+      mov esi (0x13371234 :: Word32)
+      mov esi (Addr 0)
+      pop esi
+
     getCurrentOffset :: CodeGen e s Word32
     getCurrentOffset = do
       ep <- getEntryPoint
@@ -104,15 +111,14 @@ 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 +180,28 @@ 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
+      forceRegDump
+      return $ Just (trapaddr, InstanceOf $ buildClassID cls cpidx)
+    emit' (NEW objidx) = do
+      let objname = buildClassID cls objidx
+      trapaddr <- getCurrentOffset
+      -- place something like `push $objsize' instead
+      emit32 (0x9090ffff :: Word32) >> emit8 (0x90 :: Word8)
+      callMalloc
+      -- 0x13371337 is just a placeholder; will be replaced with mtable ptr
+      mov (Disp 0, eax) (0x13371337 :: Word32)
+      return $ Just (trapaddr, NewObject objname)
+
     emit' insn = emit insn >> return Nothing
 
     emit :: J.Instruction -> CodeGen e s ()
@@ -227,20 +255,8 @@ emitFromBB cls method = do
       pop ebx -- length
       mov (Disp 0, eax) ebx -- store length at offset 0
       push eax -- push ref again
-    emit (NEW objidx) = do
-      let objname = buildClassID cls objidx
-      amount <- liftIO $ getObjectSize objname
-      push (amount :: Word32)
-      callMalloc
-      -- TODO(bernhard): save reference somewhere for GC
-      -- set method table pointer
-      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