From cfb9edba16820a3360456a502931c80da6b734a5 Mon Sep 17 00:00:00 2001 From: Eric Botcazou Date: Wed, 13 Nov 2013 12:15:47 +0000 Subject: cfgexpand.c (expand_used_vars): Allocate space for partitions based on PARM_DECLs or RESULT_DECLs only if... * cfgexpand.c (expand_used_vars): Allocate space for partitions based on PARM_DECLs or RESULT_DECLs only if they are ignored for debug info or if optimization is enabled. * tree-ssa-coalesce.c (coalesce_ssa_name): If optimization is disabled, require that all the names based on a PARM_DECL or a RESULT_DECL that isn't ignored for debug info be coalesced. From-SVN: r204742 --- gcc/tree-ssa-coalesce.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) (limited to 'gcc/tree-ssa-coalesce.c') diff --git a/gcc/tree-ssa-coalesce.c b/gcc/tree-ssa-coalesce.c index c445c78..252fc33 100644 --- a/gcc/tree-ssa-coalesce.c +++ b/gcc/tree-ssa-coalesce.c @@ -1256,8 +1256,8 @@ coalesce_ssa_name (void) cl = create_coalesce_list (); map = create_outofssa_var_map (cl, used_in_copies); - /* We need to coalesce all names originating same SSA_NAME_VAR - so debug info remains undisturbed. */ + /* If optimization is disabled, we need to coalesce all the names originating + from the same SSA_NAME_VAR so debug info remains undisturbed. */ if (!optimize) { hash_table ssa_name_hash; @@ -1278,8 +1278,16 @@ coalesce_ssa_name (void) *slot = a; else { - add_coalesce (cl, SSA_NAME_VERSION (a), SSA_NAME_VERSION (*slot), - MUST_COALESCE_COST - 1); + /* If the variable is a PARM_DECL or a RESULT_DECL, we + _require_ that all the names originating from it be + coalesced, because there must be a single partition + containing all the names so that it can be assigned + the canonical RTL location of the DECL safely. */ + const int cost + = TREE_CODE (SSA_NAME_VAR (a)) == VAR_DECL + ? MUST_COALESCE_COST - 1 : MUST_COALESCE_COST; + add_coalesce (cl, SSA_NAME_VERSION (a), + SSA_NAME_VERSION (*slot), cost); bitmap_set_bit (used_in_copies, SSA_NAME_VERSION (a)); bitmap_set_bit (used_in_copies, SSA_NAME_VERSION (*slot)); } -- cgit v1.1