diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 56e5e875e861..277ac35ad167 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -14963,6 +14963,9 @@ The maximum depth of a loop nest suitable for complete peeling. @item max-unswitch-insns The maximum number of insns of an unswitched loop. +@item max-unswitch-depth +The maximum depth of a loop nest to be unswitched. + @item lim-expensive The minimum cost of an expensive expression in the loop invariant motion. diff --git a/gcc/params.opt b/gcc/params.opt index c1dcb7ea4878..397ec0bd1288 100644 --- a/gcc/params.opt +++ b/gcc/params.opt @@ -726,6 +726,10 @@ The maximum number of instructions to consider to unroll in a loop. Common Joined UInteger Var(param_max_unswitch_insns) Init(50) Param Optimization The maximum number of insns of an unswitched loop. +-param=max-unswitch-depth= +Common Joined UInteger Var(param_max_unswitch_depth) Init(50) IntegerRange(1, 50) Param Optimization +The maximum depth of a loop nest to be unswitched. + -param=max-variable-expansions-in-unroller= Common Joined UInteger Var(param_max_variable_expansions) Init(1) Param Optimization If -fvariable-expansion-in-unroller is used, the maximum number of times that an individual variable will be expanded during loop unrolling. diff --git a/gcc/tree-ssa-loop-unswitch.cc b/gcc/tree-ssa-loop-unswitch.cc index e8c9bd6812a4..df7a2019b1c8 100644 --- a/gcc/tree-ssa-loop-unswitch.cc +++ b/gcc/tree-ssa-loop-unswitch.cc @@ -263,8 +263,10 @@ init_loop_unswitch_info (class loop *&loop, unswitch_predicate *&hottest, /* Unswitch only nests with no sibling loops. */ class loop *outer_loop = loop; + unsigned max_depth = param_max_unswitch_depth; while (loop_outer (outer_loop)->num != 0 - && !loop_outer (outer_loop)->inner->next) + && !loop_outer (outer_loop)->inner->next + && --max_depth != 0) outer_loop = loop_outer (outer_loop); hottest = NULL; hottest_bb = NULL;