From 7821bfc741f6cdf7044997ce8a9e157920765c1a Mon Sep 17 00:00:00 2001 From: Roger Sayle Date: Sat, 25 Jan 2003 21:49:52 +0000 Subject: gcse.c (bypass_last_basic_block): New global variable. * gcse.c (bypass_last_basic_block): New global variable. (bypass_block): Use redirect_edge_and_branch_force to redirect fall-through edges. Use bypass_last_basic_block to determine which blocks have valid PRE information. (bypass_conditional_jumps): Initialize bypass_last_basic_block. From-SVN: r61800 --- gcc/gcse.c | 27 ++++++++++++++++++++++----- 1 file changed, 22 insertions(+), 5 deletions(-) (limited to 'gcc/gcse.c') diff --git a/gcc/gcse.c b/gcc/gcse.c index cf724f4..a68374d 100644 --- a/gcc/gcse.c +++ b/gcc/gcse.c @@ -4527,6 +4527,13 @@ one_cprop_pass (pass, cprop_jumps, bypass_jumps) /* Bypass conditional jumps. */ +/* The value of last_basic_block at the beginning of the jump_bypass + pass. The use of redirect_edge_and_branch_force may introduce new + basic blocks, but the data flow analysis is only valid for basic + block indices less than bypass_last_basic_block. */ + +static int bypass_last_basic_block; + /* Find a set of REGNO to a constant that is available at the end of basic block BB. Returns NULL if no such set is found. Based heavily upon find_avail_set. */ @@ -4597,6 +4604,13 @@ bypass_block (bb, setcc, jump) for (e = bb->pred; e; e = enext) { enext = e->pred_next; + if (e->flags & EDGE_COMPLEX) + continue; + + /* We can't redirect edges from new basic blocks. */ + if (e->src->index >= bypass_last_basic_block) + continue; + for (i = 0; i < reg_use_count; i++) { struct reg_use *reg_used = ®_use_table[i]; @@ -4630,12 +4644,13 @@ bypass_block (bb, setcc, jump) else dest = NULL; - /* Once basic block indices are stable, we should be able - to use redirect_edge_and_branch_force instead. */ old_dest = e->dest; - if (dest != NULL && dest != old_dest - && redirect_edge_and_branch (e, dest)) - { + if (dest != NULL + && dest != old_dest + && dest != EXIT_BLOCK_PTR) + { + redirect_edge_and_branch_force (e, dest); + /* Copy the register setter to the redirected edge. Don't copy CC0 setters, as CC0 is dead after jump. */ if (setcc) @@ -4679,6 +4694,8 @@ bypass_conditional_jumps () if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR) return 0; + bypass_last_basic_block = last_basic_block; + changed = 0; FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb->next_bb, EXIT_BLOCK_PTR, next_bb) -- cgit v1.1