> here is updated patch. It should get the bounds safe enough to not have > effect on codegen of complette unrolling. > > There is IMO no way to cut the walk of loop body w/o affecting codegen in > unrolling for size mode. The condition on unroling to happen is > > unrolled_size * 2 / 3 < original_size > > The patch makes the function walking body to stop after minimal number of > duplicated insns is large (PARAM_MAX_COMPLETELY_PEELED_INSNS). The formula > above allows unlimited duplication when loop body is large enough. This is > more a bug than feature, so I think it is safe to alter it. > > Bootstrapped/regtested x86_64-linux, OK? > > Honza > > * tree-ssa-loop-ivcanon.c (tree_estimate_loop_size): Add UPPER_BOUND > parameter. > (try_unroll_loop_completely) Update.
The patch hasn't been installed, has it? The test still takes 20s to compile at -O3 on a fast x86-64 box, so you can imagine what this yields on slower machines (and that's before the x4 because of the various dg-torture options). -- Eric Botcazou
