ASM CLARIFICATION

[subbu]

I want to share one aspect that using CMP mnemonic source mem8 with imm8 data
followed by logical jump(jg or jl) doesnt give the expected result if most significant bit of data is one(act as signed integer).
example    mov   memdata1, 15h
   cmp    memdata1,0B0h
   jl   result1
   .....
   .....
result1:

jmp to result1 will NOT occur.
   
When using CMP source reg8 with imm8 data the logical jump is efective. I believe that both
combination are valid

[dedndave]

that's because the JL branch is used for signed comparisons - and the high bit is the sign bit
JB would be the unsigned counterpart

look around for a good description of "two's compliment", then use these tables

Code Select Expand


****************************************************************
Equality Branches (Used for Signed or Unsigned Comparisons)
----------------------------------------------------------------
Instruction  Description               Condition       Aliases
----------------------------------------------------------------
JZ           Jump if equal             ZF=1            JE
JNZ          Jump if not equal         ZF=0            JNE
****************************************************************

****************************************************************
Unsigned Branches
----------------------------------------------------------------
Instruction  Description               Condition       Aliases
----------------------------------------------------------------
JA           Jump if above             CF=0 and ZF=0   JNBE
JAE          Jump if above or equal    CF=0            JNC JNB
JB           Jump if below             CF=1            JC JNAE
JBE          Jump if below or equal    CF=1 or ZF=1    JNA
****************************************************************

****************************************************************
Signed Branches
----------------------------------------------------------------
Instruction  Description               Condition       Aliases
----------------------------------------------------------------
JG           Jump if greater           SF=OF or ZF=0   JNLE
JGE          Jump if greater or equal  SF=OF           JNL
JL           Jump if less              SF<>OF          JNGE
JLE          Jump if less or equal     SF<>OF or ZF=1  JNG
JO           Jump if overflow          OF=1
JNO          Jump if no overflow       OF=0
JS           Jump if sign              SF=1
JNS          Jump if no sign           SF=1
****************************************************************

[subbu]

Thank you. I agree and use this correctly.
With regards