diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/cfgexpand.c | 40 |
2 files changed, 38 insertions, 9 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 11d1778..99864a8 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2004-08-22 Richard Henderson <rth@redhat.com> + + PR 17075 + * cfgexpand.c (expand_gimple_tailcall): Detect when we can both + create new blocks and fall through. + (expand_gimple_basic_block): Update to match. + 2004-08-22 Ulrich Weigand <uweigand@de.ibm.com> * reload.c (find_reloads_address): Make return value tri-state. diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c index faa4635..b6ba991 100644 --- a/gcc/cfgexpand.c +++ b/gcc/cfgexpand.c @@ -129,10 +129,15 @@ expand_gimple_cond_expr (basic_block bb, tree stmt) /* A subroutine of expand_gimple_basic_block. Expand one CALL_EXPR that has CALL_EXPR_TAILCALL set. Returns non-null if we actually generated a tail call (something that might be denied by the ABI - rules governing the call; see calls.c). */ + rules governing the call; see calls.c). + + Sets CAN_FALLTHRU if we generated a *conditional* tail call, and + can still reach the rest of BB. The case here is __builtin_sqrt, + where the NaN result goes through the external function (with a + tailcall) and the normal result happens via a sqrt instruction. */ static basic_block -expand_gimple_tailcall (basic_block bb, tree stmt) +expand_gimple_tailcall (basic_block bb, tree stmt, bool *can_fallthru) { rtx last = get_last_insn (); edge e; @@ -145,6 +150,7 @@ expand_gimple_tailcall (basic_block bb, tree stmt) if (CALL_P (last) && SIBLING_CALL_P (last)) goto found; + *can_fallthru = true; return NULL; found: @@ -191,12 +197,17 @@ expand_gimple_tailcall (basic_block bb, tree stmt) last = NEXT_INSN (last); if (!BARRIER_P (last)) abort (); + + *can_fallthru = false; while (NEXT_INSN (last)) { /* For instance an sqrt builtin expander expands if with sibcall in the then and label for `else`. */ if (LABEL_P (NEXT_INSN (last))) - break; + { + *can_fallthru = true; + break; + } delete_insn (NEXT_INSN (last)); } @@ -277,7 +288,7 @@ expand_gimple_basic_block (basic_block bb, FILE * dump_file) for (; !bsi_end_p (bsi); bsi_next (&bsi)) { tree stmt = bsi_stmt (bsi); - basic_block new_bb = NULL; + basic_block new_bb; if (!stmt) continue; @@ -285,18 +296,29 @@ expand_gimple_basic_block (basic_block bb, FILE * dump_file) /* Expand this statement, then evaluate the resulting RTL and fixup the CFG accordingly. */ if (TREE_CODE (stmt) == COND_EXPR) - new_bb = expand_gimple_cond_expr (bb, stmt); + { + new_bb = expand_gimple_cond_expr (bb, stmt); + if (new_bb) + return new_bb; + } else { tree call = get_call_expr_in (stmt); if (call && CALL_EXPR_TAILCALL (call)) - new_bb = expand_gimple_tailcall (bb, stmt); + { + bool can_fallthru; + new_bb = expand_gimple_tailcall (bb, stmt, &can_fallthru); + if (new_bb) + { + if (can_fallthru) + bb = new_bb; + else + return new_bb; + } + } else expand_expr_stmt (stmt); } - - if (new_bb) - return new_bb; } do_pending_stack_adjust (); |