4.46 simplified
---------------
Assume for example that a in in %esi and
b in %edi, otherwise we would have to load
the pointers.

There is no cmp in Y86, we need a sub instead.
In addition, we would need to "free" registers.

1) Version with 3 cmov.

movmr (%esi),%eax ; eax = *a
movmr (%edi),%ebx ; ebx = *b
movrr %eax,%ecx   ; copy ecx = eax
sub %ebx,%ecx     ; ecx -= ebx
cmovl %eax,%ecx   ; if < then ecx = eax
cmovl %ebx,%eax   ; if < then eax = ebx
cmovl %ecx,%ebx   ; if < then ebx = ecx
movrm %eax,(%esi) ; *a = eax
movrm %ebx,(%edi) ; *b = ebx

2) Version with 2 cmov.

movmr (%esi),%eax ; eax = *a
movmr (%edi),%ebx ; ebx = *b
movrr %eax,%ecx   ; copy ecx = eax
sub %ebx,%ecx     ; ecx -= ebx
movrr %eax,%ecx   ; copy ecx = eax
movrr %ebx,%edx   ; copy edx = ebx
cmovl %edx,%eax   ; if < then eax = edx
cmovl %ecx,%ebx   ; if < then ebx = ecx
movrm %eax,(%esi) ; *a = eax
movrm %ebx,(%edi) ; *b = ebx


4.47
----
Stage      | leave
-----------+-----------------------
Fetch      | icode:ifun <- M1[PC]
           | valP <- PC+1
-----------+-----------------------
Decode     | valA <- R[%ebp]
           | valB <- R[%ebp]
-----------+-----------------------
Execute    | valE <- valB+4
-----------+-----------------------
Memory     | valM <- M4[valA]
-----------+-----------------------
Write back | R[%esp] <- valE
           | R[%ebp] <- valM
-----------+-----------------------
PC update  | PC <- valP

4.48
----
Stage      | iaddl V, rB
-----------+-----------------------
Fetch      | icode:ifun <- M1[PC]
           | rA:rB <- M1[PC+1]
           | valC <- M4[PC+2]
           | valP <- PC+6
-----------+-----------------------
Decode     | valB <- R[rB]
-----------+-----------------------
Execute    | valE <- valB+valC
-----------+-----------------------
Memory     |
-----------+-----------------------
Write back | R[rB] <- valE
-----------+-----------------------
PC update  | PC <- valP