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comparison gcc/doc/cfg.texi @ 55:77e2b8dfacca gcc-4.4.5

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update it from 4.4.3 to 4.5.0
author ryoma <e075725@ie.u-ryukyu.ac.jp>
date Fri, 12 Feb 2010 23:39:51 +0900
parents a06113de4d67
children f6334be47118
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52:c156f1bd5cd9 55:77e2b8dfacca
606 @code{tree} representation, the equivalent functions are 606 @code{tree} representation, the equivalent functions are
607 @code{bsi_insert_on_edge} which inserts a block statement 607 @code{bsi_insert_on_edge} which inserts a block statement
608 iterator on an edge, and @code{bsi_commit_edge_inserts} which flushes 608 iterator on an edge, and @code{bsi_commit_edge_inserts} which flushes
609 the instruction to actual instruction stream. 609 the instruction to actual instruction stream.
610 610
611 While debugging the optimization pass, an @code{verify_flow_info} 611 While debugging the optimization pass, a @code{verify_flow_info}
612 function may be useful to find bugs in the control flow graph updating 612 function may be useful to find bugs in the control flow graph updating
613 code. 613 code.
614 614
615 Note that at present, the representation of control flow in the 615 Note that at present, the representation of control flow in the
616 @code{tree} representation is discarded before expanding to RTL@. 616 @code{tree} representation is discarded before expanding to RTL@.
636 used on some path from @code{P} to the end of the function. With 636 used on some path from @code{P} to the end of the function. With
637 @code{UR}, it is possible to determine if there is a path from the 637 @code{UR}, it is possible to determine if there is a path from the
638 beginning of the function to @code{P} that defines the variable. 638 beginning of the function to @code{P} that defines the variable.
639 @code{LIVE} is the intersection of the @code{LR} and @code{UR} and a 639 @code{LIVE} is the intersection of the @code{LR} and @code{UR} and a
640 variable is live at @code{P} if there is both an assignment that reaches 640 variable is live at @code{P} if there is both an assignment that reaches
641 it from the beginning of the function and a uses that can be reached on 641 it from the beginning of the function and a use that can be reached on
642 some path from @code{P} to the end of the function. 642 some path from @code{P} to the end of the function.
643 643
644 In general @code{LIVE} is the most useful of the three. The macros 644 In general @code{LIVE} is the most useful of the three. The macros
645 @code{DF_[LR,UR,LIVE]_[IN,OUT]} can be used to access this information. 645 @code{DF_[LR,UR,LIVE]_[IN,OUT]} can be used to access this information.
646 The macros take a basic block number and return a bitmap that is indexed 646 The macros take a basic block number and return a bitmap that is indexed