inline procedures

[sage]

Hi, All!

For example, I'm writing inline procedure for fast fixed point multiplication.

Code:

PROCEDURE -FPMul(fp1, fp2: LONGINT): LONGINT; 
CODE {SYSTEM.i386} 
    POP     EAX 
    POP     EDX 
    IMUL    EDX  (* IMUL r/m32  (EDX:EAX <-- EAX * r/m dword) *)
    SHRD    EAX, EDX, BITS 
END FPMul;

How better to get operands inside inline procedures? Seems only POP works 
Non-inline working variant of procedure looks like:

Code:

PROCEDURE FPMul(fp1, fp2: LONGINT): LONGINT;
CODE {SYSTEM.i386}
MOV EAX, fp1[ESP]
IMUL fp2[ESP]  (* IMUL r/m32  (EDX:EAX <-- EAX * r/m dword) *)
SHRD EAX, EDX, BITS
END FPMul;

But compiler didn't allows such operations MOV EAX, fp1[ESP] nor IMUL fp2[ESP] in inline code 
Why compiler places all operands in stack in generated code? Is it possible to use registers EAX, EBX, and so on, as possible optimization here? 

[sage]

Why AO language lacks of normal inline procedures?
It seems such semantics as in assembler ones is fully suitable for this task.
It is very desired language feature

[sage]

How better to get operands inside inline procedures? Seems only POP works 

At last, with help of BohdanT I've discovered the alternative solution
If POP not used, fixing of ESP needed:

Code:

PROCEDURE -FPMul(fp1, fp2: LONGINT): LONGINT; 
CODE {SYSTEM.i386} 
    POP     EAX 
    IMUL    DWORD [ESP] 
    SHRD    EAX, EDX, BITS 
    ADD     ESP, 4 
END FPMul;

Code:

PROCEDURE -FPMul(fp1, fp2: LONGINT): LONGINT; 
CODE {SYSTEM.i386} 
    MOV     EAX, DWORD 4[ESP] 
    IMUL    DWORD [ESP] 
    SHRD    EAX, EDX, BITS 
    ADD     ESP, 8 
END FPMul;

[staubesv]

Have a look at the procedure I386.IDCT.TransformSSE. It passes parameters to the callee over registers using SYSTEM.PUTREG().