What all blocks does Block 3 & Block 5 dominate in the Flow graph for the TAC…

Dominance rule:
A block X dominates block Y if every possible path from the entry block to Y must pass through X.

Flow-graph understanding (brief)

• Block 3 contains the condition if i > j goto 105 and forms the loop control point.

• From Block 3, control can go:

  • to Block 5 (via 105), or

  • directly to Block 7 (via 111).

Because of this:

• Blocks 5, 6, 7 can be reached without necessarily passing again through Block 3.

• So Block 3 does not dominate any other block except itself.

• Block 5 contains the condition if num > b goto 107.

• From Block 5, control can:

  • go to Block 6 (107), or

  • go directly to Block 7 (111).

Since blocks 6 and 7 can be reached via paths not passing through Block 5,
Block 5 only dominates itself.

Final Answer

• Block 3 dominates: 3

• Block 5 dominates: 5