Abstract: The ILP(instruction-level-parallel) becomes more and more important for improving the microprocessor’s speed.The if-convertion technology is an effective compiler-optimization method of facilitating exploiting ILP based on the microprocessor which supplies conditional execution．After introducing if-convertion technology and algorithm of GCC and transplanting it into the Matrix compiler successfully,some improvements for if-convertion of Matrix compi-ler were made．Experiment results indicate that the if-convertion achieved in the paper can remove the branches,reduce the number of basic-blocks and broaden the bound of basic-block．It can also facilitate making more predominant codes for compiler.

Key words: Predicate execution,If-convertion,Conditional execution,ILP,Matrix,VLIW