diff options
| -rw-r--r-- | lib/hipe/regalloc/hipe_regalloc_prepass.erl | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/lib/hipe/regalloc/hipe_regalloc_prepass.erl b/lib/hipe/regalloc/hipe_regalloc_prepass.erl index 5a52e5ad51..c2531bc451 100644 --- a/lib/hipe/regalloc/hipe_regalloc_prepass.erl +++ b/lib/hipe/regalloc/hipe_regalloc_prepass.erl @@ -60,8 +60,8 @@ -define(TUNE_TOO_FEW_BBS, 256). %% Ignore the ra_partitioned option (and do whole function RA instead) when -%% there are fewer than ?TUNE_MIN_SPLIT_PSEUDOS non-spilled used pseudos. --define(TUNE_MIN_SPLIT_PSEUDOS, 1024). +%% there are fewer than ?TUNE_MIN_SPLIT_BBS basic blocks. +-define(TUNE_MIN_SPLIT_BBS, 384). %% We present a "pseudo-target" to the register allocator we wrap. %% Note: all arities are +1 as we're currently using the parameterised module @@ -145,7 +145,12 @@ regalloc(RegAllocMod, CFG, SpillIndex0, SpillLimit, Target, Options) -> Liveness), {Coloring, SpillIndex, Liveness}. -%% regalloc_initial/6 is allowed to introduce new temporaries, unlike regalloc/6 +%% regalloc_initial/6 is allowed to introduce new temporaries, unlike +%% regalloc/6. +%% In order for regalloc/6 to never introduce temporaries, regalloc/6 must never +%% choose to do split allocation unless regalloc_initial/6 does. This is the +%% reason that the splitting heuristic is solely based on the number of basic +%% blocks, which does not change during the register allocation loop. -spec regalloc_initial(module(), target_cfg(), spillno(), spillno(), module(), proplists:proplist()) -> {hipe_map(), spillno(), target_cfg(), @@ -169,12 +174,11 @@ regalloc_1(RegAllocMod, CFG0, SpillIndex0, SpillLimit, Target, Options, {ScanBBs, Seen, SpillMap, SpillIndex1} = scan_cfg(CFG0, Liveness, SpillIndex0, Target), - AllPrecoloured = Target:all_precoloured(), - {PartColoring, SpillIndex, NewCFG} = - case proplists:get_bool(ra_partitioned, Options) of - true when map_size(Seen) - map_size(SpillMap) - length(AllPrecoloured) - > ?TUNE_MIN_SPLIT_PSEUDOS -> + case proplists:get_bool(ra_partitioned, Options) + andalso length(Target:labels(CFG0)) > ?TUNE_MIN_SPLIT_BBS + of + true -> regalloc_partitioned(SpillMap, SpillIndex1, SpillLimit, ScanBBs, CFG0, Target, RegAllocMod, Options); _ -> @@ -186,6 +190,7 @@ regalloc_1(RegAllocMod, CFG0, SpillIndex0, SpillLimit, Target, Options, Coloring = SpillColors ++ PartColoring, ?ASSERT(begin + AllPrecoloured = Target:all_precoloured(), MaxPhys = lists:max(AllPrecoloured) + 1, Unused = unused(live_pseudos(Seen, SpillMap, MaxPhys), SpillMap, CFG0, Target), |