* profile.c: Add file comment describing the overall algorithm and

	structures.
	(struct edge_info): Add comments.
	(struct bb_info): Add comments.
	* basic-block.h (EDGE_*): Add comments.
	* doc/gcov.texi (Gcov Data Files): Document bit flags.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@55842 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 25 insertions, 7 deletions

diff --git a/gcc/doc/gcov.texi b/gcc/doc/gcov.texi
index 5f5f18bd6d1..6b0fd82d852 100644
--- a/gcc/doc/gcov.texi
+++ b/gcc/doc/gcov.texi
@@ -348,12 +348,13 @@ functions within those files, and line numbers corresponding to each
 basic block in the source file.
 
 The @file{.bb} file format consists of several lists of 4-byte integers
-which correspond to the line numbers of each basic block in the
-file.  Each list is terminated by a line number of 0.  A line number of @minus{}1
-is used to designate that the source file name (padded to a 4-byte
-boundary and followed by another @minus{}1) follows.  In addition, a line number
-of @minus{}2 is used to designate that the name of a function (also padded to a
-4-byte boundary and followed by a @minus{}2) follows.
+which correspond to the line numbers of each basic block in the file.
+Each list is terminated by a line number of 0.  A line number of
+@minus{}1 is used to designate that the source file name (padded to a
+4-byte boundary and followed by another @minus{}1) follows.  In
+addition, a line number of @minus{}2 is used to designate that the name
+of a function (also padded to a 4-byte boundary and followed by a
+@minus{}2) follows.
 
 The @file{.bbg} file is used to reconstruct the program flow graph for
 the source file.  It contains a list of the program flow arcs (possible
@@ -388,6 +389,22 @@ correctly.
 The function name is stored as a @minus{}1 (4 bytes), the length (4 bytes),
 the name itself (padded to 4-byte boundary) followed by a @minus{}1 (4 bytes).
 
+The flags are defined as follows:
+@itemize
+@item bit0 
+On function spanning tree
+
+@item bit1
+Is a fake edge
+
+@item bit2
+Is the fall through edge from one block to its immediate successor.
+
+@item bit3-bit31
+For future expansion
+
+@end itemize
+
 The @file{.da} file is generated when a program containing object files
 built with the GCC @option{-fprofile-arcs} option is executed.  A
 separate @file{.da} file is created for each source file compiled with
@@ -395,7 +412,8 @@ this option, and the name of the @file{.da} file is stored as an
 absolute pathname in the resulting object file.  This path name is
 derived from the source file name by substituting a @file{.da} suffix.
 
-The @file{.da} consists of several blocks (one for each run) with the following structure:
+The @file{.da} consists of several blocks (one for each run) with the
+following structure:
 @smallexample
         "magic" number @minus{}123 (4-byte number)
 	number of functions (4-byte number)