ThinBASIC Core Language > Machine Code > MC

Description

Evaluate a string and return its representation in machine code.

Syntax

MachineCodeString = MC_Eval$(StringToEval)

Returns

String.

Parameters

Name	Type	Optional	Meaning
StringToEval	String	No	String to evaluate into machine code

Remarks

Rules:

Restrictions

See also

Examples

' Using Machine Code with ThinBasic

'---------------------------------------------------------------------------

'---Reference:

' Intel x86 Architecture Ref Manual Vol 2

'---http://developer.intel.com/design/pentiumii/manuals/243191.htm

'---------------------------------------------------------------------------

' Syntax rules:

' #Variable patches in long address of Variable (4 bytes)

' NLn patches in long decimal value n (4 bytes)

' comments are indicated by a quote mark '

' all other words are read as hexadecimal bytes.

' An error during MC_Eval$ will produce a string containing &hc3 (ret) only.

'----------------------------------------------

' CPUID

' Identifying some key CPU features

' see page 3-111 in the manual above

'----------------------------------------------

Dim sMC As String

sMC = MC_EVAL$ "

b8 01 00 00 00 ' mov eax,1 request feature info in edx

0f a2 ' cpuid

8b c2 ' mov eax,edx

c3 ' ret

'----------------------------------------------

' ---Invoke the machine code string

Dim RetVal As Long = MC_Exec(sMC)

Dim s As String="CPU Features:" + $crlf

If Retval And &h0000001 Then s += "FPU " + $crlf ' bit0 FPU

If RetVal And &h0008000 Then s += "CMOV " + $crlf ' bit15 CMOV

If RetVal And &h0010000 Then s += "FGPAT" + $crlf ' bit16 FGPAT

If RetVal And &h0800000 Then s += "MMX " + $crlf ' bit23 MMX

If RetVal And &h1000000 Then s += "FXR " + $crlf ' bit24 FXSAVE / FXRSTOR

If RetVal And &h2000000 Then s += "XMM (streaming simd)" + $crlf ' bit25 XMM streaming SIMD

MSGBOX 0, hex$(RetVal) + $crlf + $crlf + s

'----------------------------------------------