Nokia Corporation

Attila Bicsák

Tibor Gyimóthy

Ákos Kiss

Rudolf Ferenc

Gábor Lehotai

A method and a device for abstracting instruction sequences in a computer program. First, a control flow graph of the program is generated and analysed in order to detect multiple occurrences of a same instruction sequence (). Then, a function including the longest sequence common to at least two instruction sequences from a plurality of sequences having a common instruction sequence of equal or shorter length compared to the longest sequence is created (). Finally, the original occurrences of the instruction sequences in the plurality of sequences with a reference to a proper position in the newly created function are deleted and a reference to a proper position in the created function inserted instead ().

Method and a device for abstracting instruction sequences with tail merging

A method and a system for constructing a control flow graph (CFG,) from an executable computer program (). The solution detects data intermixed with instructions and instruction set changes. The method includes the steps of defining block leader types specifying basic block boundaries in the program (), building a CFG structure () according to the basic blocks found in the program, and adding control flow and addressing information to the CFG () by propagating through the basic blocks and internals thereof. The CFG () may be then optimised () and a compacted executable () created as a result.

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Helsinki, Finland

Attila Bicsák