You are right, we need discriminator for non-CALL stmts too. Patch updated:
Index: gcc/tree-cfg.c
===================================================================
--- gcc/tree-cfg.c (revision 201858)
+++ gcc/tree-cfg.c (working copy)
@@ -781,9 +781,37 @@ assign_discriminators (void)
{
edge e;
edge_iterator ei;
+ gimple_stmt_iterator gsi;
gimple last = last_stmt (bb);
location_t locus = last ? gimple_location (last) : UNKNOWN_LOCATION;
+ location_t curr_locus = UNKNOWN_LOCATION;
+ int curr_discr = 0;
+ /* Traverse the basic block, if two function calls within a basic block
+ are mapped to a same line, assign a new discriminator because a call
+ stmt could be a split point of a basic block. */
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ gimple stmt = gsi_stmt (gsi);
+ if (curr_locus == UNKNOWN_LOCATION)
+ {
+ curr_locus = gimple_location (stmt);
+ }
+ else if (!same_line_p (curr_locus, gimple_location (stmt)))
+ {
+ curr_locus = gimple_location (stmt);
+ curr_discr = 0;
+ }
+ else if (curr_discr != 0)
+ {
+ gimple_set_location (stmt, location_with_discriminator (
+ gimple_location (stmt), curr_discr));
+ }
+ /* Allocate a new discriminator for CALL stmt. */
+ if (gimple_code (stmt) == GIMPLE_CALL)
+ curr_discr = next_discriminator_for_locus (curr_locus);
+ }
+
if (locus == UNKNOWN_LOCATION)
continue;
On Tue, Aug 20, 2013 at 2:54 PM, Cary Coutant <ccout...@google.com> wrote:
>> This patch assigns discriminators for different callsites within the
>> same BB. This is needed for accurate profile attribution in AutoFDO.
>>
>> Testing on going.
>>
>> OK for google branches if test pass?
>
>> + for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
>> + {
>> + gimple stmt = gsi_stmt (gsi);
>> + if (gimple_code (stmt) != GIMPLE_CALL)
>> + continue;
>> + if (curr_locus == UNKNOWN_LOCATION ||
>> + !same_line_p (curr_locus, gimple_location (stmt)))
>> + curr_locus = gimple_location (stmt);
>> + else
>> + gimple_set_location (stmt, location_with_discriminator (
>> + gimple_location (stmt),
>> + next_discriminator_for_locus (gimple_location (stmt))));
>> + }
>
> Please add a comment above this block explaining what it's doing. Are
> you sure it's sufficient to just assign a new discriminator to the
> CALL stmt, and not to the subsequent stmts after the CALL?
>
> -cary
