41 lines
1.5 KiB
C
41 lines
1.5 KiB
C
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/* C O P Y P R O P A G A T I O N */
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extern line_p *copies; /* table of copies; every entry points to the
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* store-instruction.
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*/
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extern short *def_to_copynr; /* Table that maps a 'definition'-number to a
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* 'copy' number.
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*/
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extern short nrcopies; /* number of copies in the current procedure
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* (length of copies-table)
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*/
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extern copy_analysis(); /* (proc_p p)
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* Determine which copies procedure p has.
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* Compute C_IN(b), for every basic block b.
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*/
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extern bool is_copy(); /* (line_p def)
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* See if the definition def is also a 'copy',
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* i.e. an statement of the form
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* 'A := B' (or, in EM terminology:
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* a sequence 'Load Variable; Store Variable').
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*/
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extern fold_var(); /* (line_p old,new; bblock_p b)
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* The variable referenced by the
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* EM instruction 'old' must be replaced
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* by the variable referenced by 'new'.
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*/
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extern bool value_retained(); /* (line_p copy; short defnr; line_p use;
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* bblock_p b)
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* See if the right hand side variable of the
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* copy still has the same value at 'use'.
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* If the copy and the use are in the same
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* basic block (defnr = 0), search from the
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* copy to the use, to see if the rhs variable
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* is changed. If the copy is in another block,
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* defnr is the definition-number of the copy.
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* Search from the beginning of the block to
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* the use, to see if the rhs is changed;
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* if not, check that the copy is in C_IN(b).
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*/
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