diff options
Diffstat (limited to 'gcc/fwprop.c')
| -rw-r--r-- | gcc/fwprop.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/gcc/fwprop.c b/gcc/fwprop.c index 285fb1a..0ab25ef 100644 --- a/gcc/fwprop.c +++ b/gcc/fwprop.c @@ -120,6 +120,13 @@ static vec<df_ref> use_def_ref; static vec<df_ref> reg_defs; static vec<df_ref> reg_defs_stack; +/* The maximum number of propagations that are still allowed. If we do + more propagations than originally we had uses, we must have ended up + in a propagation loop, as in PR79405. Until the algorithm fwprop + uses can obviously not get into such loops we need a workaround like + this. */ +static int propagations_left; + /* The MD bitmaps are trimmed to include only live registers to cut memory usage on testcases like insn-recog.c. Track live registers in the basic block and do not perform forward propagation if the @@ -1407,6 +1414,8 @@ forward_propagate_into (df_ref use) if (forward_propagate_and_simplify (use, def_insn, def_set) || forward_propagate_subreg (use, def_insn, def_set)) { + propagations_left--; + if (cfun->can_throw_non_call_exceptions && find_reg_note (use_insn, REG_EH_REGION, NULL_RTX) && purge_dead_edges (DF_REF_BB (use))) @@ -1434,6 +1443,8 @@ fwprop_init (void) active_defs = XNEWVEC (df_ref, max_reg_num ()); if (flag_checking) active_defs_check = sparseset_alloc (max_reg_num ()); + + propagations_left = DF_USES_TABLE_SIZE (); } static void @@ -1480,6 +1491,9 @@ fwprop (void) for (i = 0; i < DF_USES_TABLE_SIZE (); i++) { + if (!propagations_left) + break; + df_ref use = DF_USES_GET (i); if (use) if (DF_REF_TYPE (use) == DF_REF_REG_USE @@ -1540,6 +1554,9 @@ fwprop_addr (void) end, and we'll go through them as well. */ for (i = 0; i < DF_USES_TABLE_SIZE (); i++) { + if (!propagations_left) + break; + df_ref use = DF_USES_GET (i); if (use) if (DF_REF_TYPE (use) != DF_REF_REG_USE |