7 Conditional Branches

Conditional branches:

• Branch to a label intsruction if a condition is true

  • otherwise continue sequentially

• beq (branch equal)

  • beq rs1, rs2, L1
    • if (rs1==rs2) branch instruction labeled L1
      • telling cpu if rs1 == rs2 it reads whatever L1 (memory address)
      • if not true continue code skip

• bne (branch not equal)

  • bne rs1, rs2, L1
    • if (rs1 != rs2) branch instruction labeled L1
      • telling cpu if rs1 != rs2 read whatever L1 (memory address)
      • if true continue code skip

• If statement

Conditional branch-less

• much like branches but differnet

• blt

  • blt rs1, rs2, L1
  • if rs1<rs2 branch to instruction labeled L1
    • for unsigned use bltu

• bge

  • bge rs1, rs2, L1
  • if rs1 >= rs2 branch to instruction labeled L1
    • for unsigned use bge

Basic blocks

• basicl blocks is a sequence of instruction with no branches or any jumps

  • forced sequence