| 摘要 |
PROBLEM TO BE SOLVED: To provide a compiler device that can optimize loop processing by software pipelining significantly effective in reducing the number of execution cycles. SOLUTION: The insertion of a mov instruction into an st instruction of a cyclic path shown in Figure 2 (a) creates a state shown in Figure 2 (b). Specifically, the st instruction is replaced by an instruction "st (r4), r2" where an unused register r4 replaces a register r1 that is a parameter of carried dependence used in the st instruction, and a transfer instruction "mov r4, r1" to store a value stored in the original parameter register r1 into the register r4 is inserted. The insertion of the mov instruction into the cyclic path root can divide the cyclic path of a four-cycle cyclic path length in two, that is, a cyclic path of a three-cycle cyclic path length and a cyclic path of a one-cycle cyclic path length, to reduce the start interval of loop processing. COPYRIGHT: (C)2007,JPO&INPIT
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