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Diffstat (limited to 'gcc/doc/loop.texi')
| -rw-r--r-- | gcc/doc/loop.texi | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/gcc/doc/loop.texi b/gcc/doc/loop.texi index 642a52374d4..354241f14c7 100644 --- a/gcc/doc/loop.texi +++ b/gcc/doc/loop.texi @@ -63,20 +63,25 @@ The root of this tree is a fake loop that contains all blocks in the function. Each of the loops is represented in a @code{struct loop} structure. Each loop is assigned an index (@code{num} field of the @code{struct loop} structure), and the pointer to the loop is stored in -the corresponding field of the @code{parray} field of the loops +the corresponding field of the @code{larray} vector in the loops structure. Index of a sub-loop is always greater than the index of its super-loop. The indices do not have to be continuous, there may be -empty (@code{NULL}) entries in the @code{parray} created by deleting -loops. The index of a loop never changes. The first unused index is -stored in the @code{num} field of the loops structure. +empty (@code{NULL}) entries in the @code{larray} created by deleting +loops. The index of a loop never changes. + +The entries of the @code{larray} field should not be accessed directly. +The function @code{get_loop} returns the loop description for a loop with +the given index. @code{number_of_loops} function returns number of +loops in the function. To traverse all loops, use @code{FOR_EACH_LOOP} +macro. The @code{flags} argument of the macro is used to determine +the direction of traversal and the set of loops visited. Each basic block contains the reference to the innermost loop it belongs to (@code{loop_father}). For this reason, it is only possible to have one @code{struct loops} structure initialized at the same time for each -CFG. It is recommended to use the global variable @code{current_loops} -to contain the @code{struct loops} structure, especially if the loop -structures are updated throughout several passes. Many of the loop -manipulation functions assume that dominance information is up-to-date. +CFG. The global variable @code{current_loops} contains the +@code{struct loops} structure. Many of the loop manipulation functions +assume that dominance information is up-to-date. The loops are analyzed through @code{loop_optimizer_init} function. The argument of this function is a set of flags represented in an integer |