[Mono-list] cpblk?

[Michael Giagnocavo]

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>> 	Just assemble this -- it is a very simple case.  It also
>> demonstrates how the cpblk doesn't have to work when the src and dest
>> addresses overlap.  Test it on MSFT's CLR and you'll see that it
>> eventually fails (and sometimes works).  It'd be cool if Mono's
always
>> worked (even though Partition III specifies "unspecified" behaviour
if
>> src and dest overlap).

> I just implemented it using unix memcpy(). Doku for memcpy states it
> does not work for overlapping regions, but IMO it makes no sense to
make
> that work, it only makes things slower.

Hmm.  What if I want to move a block up by a few bytes?

>> 	This is only a lame test, I'm working on a much longer test
>> that's more accurate (protects IP) -- if you like I can send that
later.

> I would like to have a test that fails if CPBLK does not work. Your
test
> even pass if i implement CPBLK as NOP! 

Well, not a NOP, since then the program would be invalid (throws me a
System.InvalidProgramException, since NOP does not have the same
signature.  But you're right, I shouldn't have sent such bad code.

>> 	Is jmp implemented?

> No, but I will implement it as soon as I get some code to test ;-)

Here are you two simple working tests that will print PASS or FAIL.
Which other opcodes need a test?

Thanks,
-Mike

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.assembly extern mscorlib{}
.assembly jmpTest{}
.module jmpTest

.class private auto ansi jmpTest
       extends [mscorlib]System.Object {

  .method public static void  go() cil managed {
    .entrypoint

	jmp void [jmpTest]jmpTest::pass()

	ldstr "FAIL"
	call void [mscorlib]System.Console::WriteLine(string)
	ret
  }

  .method public static void pass() cil managed{

	ldstr "PASS"
	call void [mscorlib]System.Console::WriteLine(string)
	ret
  }


} 
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.assembly extern mscorlib{}
.assembly cpblkTest{}
.module cpblkTest

.class private auto ansi test
       extends [mscorlib]System.Object {

  .field private static valuetype DataType dataField at theData
  .method public static void  start() cil managed {
	.entrypoint
	.locals init(int32, unsigned int8)

	//store data address
	ldsflda valuetype DataType test::dataField
	stloc.0

	//copy 7 to first position
	ldloc.0		//dest
	ldloc.0
	ldc.i4.6 
	add		//src
	ldc.i4.1	//size
    	cpblk

	//ldind value
	ldloc.0
	ldind.u1
	
	//compare
	ldc.i4.7
	beq PASS

  FAIL:
	ldstr "FAIL"
	call void [mscorlib]System.Console::WriteLine(string)
	ret
  PASS:
	ldstr "PASS"
	call void [mscorlib]System.Console::WriteLine(string)
	ret
  } 

}

.class public explicit ansi sealed DataType 
       extends [mscorlib]System.ValueType
	{.pack 1 .size 10}

.data theData = bytearray (1 2 3 4 5 6 7 8 9 10)
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