loop splitting

[gcc.git] / gcc / doc / passes.texi

diff --git a/gcc/doc/passes.texi b/gcc/doc/passes.texi
index ef5548b2aa688e22049a92164764ca4a55a994ef..bffc3e3ee2b44705a8041b16d04a55726c9e9b2a 100644 (file)
--- a/gcc/doc/passes.texi
+++ b/gcc/doc/passes.texi
@@ -484,6 +484,12 @@ out of the loops.  To achieve this, a duplicate of the loop is created for
 each possible outcome of conditional jump(s).  The pass is implemented in
 @file{tree-ssa-loop-unswitch.c}.
 
+Loop splitting.  If a loop contains a conditional statement that is
+always true for one part of the iteration space and false for the other
+this pass splits the loop into two, one dealing with one side the other
+only with the other, thereby removing one inner-loop conditional.  The
+pass is implemented in @file{tree-ssa-loop-split.c}.
+
 The optimizations also use various utility functions contained in
 @file{tree-ssa-loop-manip.c}, @file{cfgloop.c}, @file{cfgloopanal.c} and
 @file{cfgloopmanip.c}.