On 4 April 2016 at 17:30, Jan Hubicka <[email protected]> wrote: >> > Um not sure if I understood correctly. >> > Do we want to constrain individual partition size by adding parameter >> > lto-max-partition >> > for balanced partitioning but not for -flto-partition=one >> > case (since latter would also change semantics of =one) ? >> >> Yes, I think so. > > Yep, I agree. Having partition one that produces multiple partitions doesn't > seem to make much sense. > Given that we have such not so predictable target specific limits on size of > single translation unit > we can handle, I suppose adding a resonable limit to the default balanced > partitioning makes more sense. > One can always push the behaviour you intend by setting max partitions to 1 > (I suppose max size should > have precedence over max partitions) Thanks for the suggestions, I have updated the patch. Is it OK if it passes bootstrap+test ?
Thanks, Prathamesh > > Honza >> >> Richard. >> >> > Thanks, >> > Prathamesh >> > > >> > > Richard. >> > > >> > > -- >> > > Richard Biener <[email protected]> >> > > SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, >> > > HRB 21284 (AG Nuernberg) >> > >> > >> >> -- >> Richard Biener <[email protected]> >> SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB >> 21284 (AG Nuernberg)
diff --git a/gcc/lto/lto-partition.c b/gcc/lto/lto-partition.c
index 9eb63c2..bc0c612 100644
--- a/gcc/lto/lto-partition.c
+++ b/gcc/lto/lto-partition.c
@@ -511,9 +511,20 @@ lto_balanced_map (int n_lto_partitions)
varpool_order.qsort (varpool_node_cmp);
/* Compute partition size and create the first partition. */
+ if (PARAM_VALUE (MIN_PARTITION_SIZE) > PARAM_VALUE (MAX_PARTITION_SIZE))
+ fatal_error (input_location, "min partition size cannot be greater than
max partition size");
+
partition_size = total_size / n_lto_partitions;
if (partition_size < PARAM_VALUE (MIN_PARTITION_SIZE))
partition_size = PARAM_VALUE (MIN_PARTITION_SIZE);
+ else if (partition_size > PARAM_VALUE (MAX_PARTITION_SIZE))
+ {
+ n_lto_partitions = total_size / PARAM_VALUE (MAX_PARTITION_SIZE);
+ if (total_size % PARAM_VALUE (MAX_PARTITION_SIZE))
+ n_lto_partitions++;
+ partition_size = total_size / n_lto_partitions;
+ }
+
npartitions = 1;
partition = new_partition ("");
if (symtab->dump_file)
diff --git a/gcc/lto/lto.c b/gcc/lto/lto.c
index 9dd513f..294b8a4 100644
--- a/gcc/lto/lto.c
+++ b/gcc/lto/lto.c
@@ -3112,6 +3112,12 @@ do_whole_program_analysis (void)
timevar_pop (TV_WHOPR_WPA);
timevar_push (TV_WHOPR_PARTITIONING);
+
+ if (flag_lto_partition != LTO_PARTITION_BALANCED
+ && PARAM_VALUE (MAX_PARTITION_SIZE) != INT_MAX)
+ fatal_error (input_location, "--param max-lto-partition should only"
+ " be used with balanced partitioning\n");
+
if (flag_lto_partition == LTO_PARTITION_1TO1)
lto_1_to_1_map ();
else if (flag_lto_partition == LTO_PARTITION_MAX)
diff --git a/gcc/params.def b/gcc/params.def
index 9362c15..b6055ff 100644
--- a/gcc/params.def
+++ b/gcc/params.def
@@ -1029,6 +1029,11 @@ DEFPARAM (MIN_PARTITION_SIZE,
"Minimal size of a partition for LTO (in estimated instructions).",
1000, 0, 0)
+DEFPARAM (MAX_PARTITION_SIZE,
+ "lto-max-partition",
+ "Maximal size of a partition for LTO (in estimated instructions).",
+ INT_MAX, 0, INT_MAX)
+
/* Diagnostic parameters. */
DEFPARAM (CXX_MAX_NAMESPACES_FOR_DIAGNOSTIC_HELP,
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