diff options
Diffstat (limited to 'gcc/ddg.c')
| -rw-r--r-- | gcc/ddg.c | 43 |
1 files changed, 41 insertions, 2 deletions
diff --git a/gcc/ddg.c b/gcc/ddg.c index b8ae375f153..d06bdbb5448 100644 --- a/gcc/ddg.c +++ b/gcc/ddg.c @@ -390,6 +390,33 @@ insns_may_alias_p (rtx insn1, rtx insn2) &PATTERN (insn2)); } +/* Given two nodes, analyze their RTL insns and add intra-loop mem deps + to ddg G. */ +static void +add_intra_loop_mem_dep (ddg_ptr g, ddg_node_ptr from, ddg_node_ptr to) +{ + + if ((from->cuid == to->cuid) + || !insns_may_alias_p (from->insn, to->insn)) + /* Do not create edge if memory references have disjoint alias sets + or 'to' and 'from' are the same instruction. */ + return; + + if (mem_write_insn_p (from->insn)) + { + if (mem_read_insn_p (to->insn)) + create_ddg_dep_no_link (g, from, to, + DEBUG_INSN_P (to->insn) + ? ANTI_DEP : TRUE_DEP, MEM_DEP, 0); + else + create_ddg_dep_no_link (g, from, to, + DEBUG_INSN_P (to->insn) + ? ANTI_DEP : OUTPUT_DEP, MEM_DEP, 0); + } + else if (!mem_read_insn_p (to->insn)) + create_ddg_dep_no_link (g, from, to, ANTI_DEP, MEM_DEP, 0); +} + /* Given two nodes, analyze their RTL insns and add inter-loop mem deps to ddg G. */ static void @@ -477,10 +504,22 @@ build_intra_loop_deps (ddg_ptr g) if (DEBUG_INSN_P (j_node->insn)) continue; if (mem_access_insn_p (j_node->insn)) - /* Don't bother calculating inter-loop dep if an intra-loop dep - already exists. */ + { + /* Don't bother calculating inter-loop dep if an intra-loop dep + already exists. */ if (! TEST_BIT (dest_node->successors, j)) add_inter_loop_mem_dep (g, dest_node, j_node); + /* If -fmodulo-sched-allow-regmoves + is set certain anti-dep edges are not created. + It might be that these anti-dep edges are on the + path from one memory instruction to another such that + removing these edges could cause a violation of the + memory dependencies. Thus we add intra edges between + every two memory instructions in this case. */ + if (flag_modulo_sched_allow_regmoves + && !TEST_BIT (dest_node->predecessors, j)) + add_intra_loop_mem_dep (g, j_node, dest_node); + } } } } |