From 63d0f6ab560336d34b0a8f9b9b111c4a17e8737f Mon Sep 17 00:00:00 2001 From: Segher Boessenkool Date: Wed, 18 May 2016 12:58:57 +0200 Subject: [PATCH] function: Do the CLEANUP_EXPENSIVE after shrink-wrapping, not before We should do CLEANUP_EXPENSIVE after shrink-wrapping, because shrink- wrapping creates constructs that CLEANUP_EXPENSIVE can optimise, and nothing runs CLEANUP_EXPENSIVE later. * function.c (rest_of_handle_thread_prologue_and_epilogue): Call cleanup_cfg with CLEANUP_EXPENSIVE after shrink-wrapping instead of before. Add a comment. From-SVN: r236372 --- gcc/ChangeLog | 6 ++++++ gcc/function.c | 6 ++++-- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index a011528db7c..4d119bdcef8 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2016-05-18 Segher Boessenkool + + * function.c (rest_of_handle_thread_prologue_and_epilogue): Call + cleanup_cfg with CLEANUP_EXPENSIVE after shrink-wrapping instead + of before. Add a comment. + 2016-05-18 Bin Cheng * tree-ssa-loop-ivopts.c (get_computation_cost_at): Check invariant diff --git a/gcc/function.c b/gcc/function.c index 70584b95586..9cbe71f2521 100644 --- a/gcc/function.c +++ b/gcc/function.c @@ -6369,8 +6369,10 @@ make_pass_leaf_regs (gcc::context *ctxt) static unsigned int rest_of_handle_thread_prologue_and_epilogue (void) { + /* prepare_shrink_wrap is sensitive to the block structure of the control + flow graph, so clean it up first. */ if (optimize) - cleanup_cfg (CLEANUP_EXPENSIVE); + cleanup_cfg (0); /* On some machines, the prologue and epilogue code, or parts thereof, can be represented as RTL. Doing so lets us schedule insns between @@ -6384,7 +6386,7 @@ rest_of_handle_thread_prologue_and_epilogue (void) /* Shrink-wrapping can result in unreachable edges in the epilogue, see PR57320. */ - cleanup_cfg (0); + cleanup_cfg (optimize ? CLEANUP_EXPENSIVE : 0); /* The stack usage info is finalized during prologue expansion. */ if (flag_stack_usage_info) -- 2.30.2