Redundant (Common) Subexpression Elimination

Global Constant Folding and Propagation

Dead Code Elimination

Conditional Pruning

Conditional Reordering

Assignment Elimination Due to Equality

GOTO Chasing

Array Temporary Elimination

From reaching definitions, a use-definition chain, ud-chain, can be constructed. This is a list of variable definitions linked with their uses. Within a block, a definition is matched to its subsequent use. If there is no definition within the block, then all definitions which reach the block are matched with the use.

The ud-chain may be used for constant propagation.

This can be optimized still further with an algebraic substitution and a dead code elimination. The result is shown in Example 14.

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