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Diffstat (limited to 'gcc/doc/passes.texi')
| -rw-r--r-- | gcc/doc/passes.texi | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/gcc/doc/passes.texi b/gcc/doc/passes.texi index 94b9ae5b23a..9867e7323ef 100644 --- a/gcc/doc/passes.texi +++ b/gcc/doc/passes.texi @@ -363,9 +363,20 @@ and is described by @code{pass_pre}. @item Loop optimization -TODO: Presumably we're going to do something with loops here. At -present we don't, and this is a placeholder. The pass is located -in @file{tree-ssa-loop.c} and is described by @code{pass_loop}. +The main driver of the pass is placed in @file{tree-ssa-loop.c} +and described by @code{pass_loop}. + +The optimizations performed by this pass are: + +Loop invariant motion. This pass moves only invariants that +would be hard to handle on rtl level (function calls, operations that expand to +nontrivial sequences of insns). With @option{-funswitch-loops} it also moves +operands of conditions that are invariant out of the loop, so that we can use +just trivial invariantness analysis in loop unswitching. The pass also includes +store motion. The pass is implemented in @file{tree-ssa-loop-im.c}. + +The optimizations also use various utility functions contained in +@file{cfgloop.c}, @file{cfgloopanal.c} and @file{cfgloopmanip.c}. @item Conditional constant propagation |