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25 * \file ir_basic_block.cpp
27 * Basic block analysis of instruction streams.
31 #include "ir_basic_block.h"
34 * Calls a user function for every basic block in the instruction stream.
36 * Basic block analysis is pretty easy in our IR thanks to the lack of
37 * unstructured control flow. We've got:
39 * ir_loop (for () {}, while () {}, do {} while ())
45 * Note that the basic blocks returned by this don't encompass all
46 * operations performed by the program -- for example, if conditions
47 * don't get returned, nor do the assignments that will be generated
48 * for ir_call parameters.
50 void call_for_basic_blocks(exec_list
*instructions
,
51 void (*callback
)(ir_instruction
*first
,
56 ir_instruction
*leader
= NULL
;
57 ir_instruction
*last
= NULL
;
59 foreach_in_list(ir_instruction
, ir
, instructions
) {
62 ir_function
*ir_function
;
67 if ((ir_if
= ir
->as_if())) {
68 callback(leader
, ir
, data
);
71 call_for_basic_blocks(&ir_if
->then_instructions
, callback
, data
);
72 call_for_basic_blocks(&ir_if
->else_instructions
, callback
, data
);
73 } else if ((ir_loop
= ir
->as_loop())) {
74 callback(leader
, ir
, data
);
76 call_for_basic_blocks(&ir_loop
->body_instructions
, callback
, data
);
77 } else if (ir
->as_jump() || ir
->as_call()) {
78 callback(leader
, ir
, data
);
80 } else if ((ir_function
= ir
->as_function())) {
81 /* A function definition doesn't interrupt our basic block
82 * since execution doesn't go into it. We should process the
83 * bodies of its signatures for BBs, though.
85 * Note that we miss an opportunity for producing more
86 * maximal BBs between the instructions that precede main()
87 * and the body of main(). Perhaps those instructions ought
88 * to live inside of main().
90 foreach_in_list(ir_function_signature
, ir_sig
, &ir_function
->signatures
) {
91 call_for_basic_blocks(&ir_sig
->body
, callback
, data
);
97 callback(leader
, last
, data
);