Re: [PATCH] Fix PR tree-optimization/77550

[Richard Biener <rguenther at suse dot de>]

On Sun, 18 Sep 2016, Bernd Edlinger wrote:

> Hi,
> 
> this PR shows that in vectorizable_store and vectorizable_load
> as well, the vector access always uses the first dr as the alias
> type for the whole access.  But that is not right, if they are
> different types, like in this example.
> 
> So I tried to replace all reference_alias_ptr_type (DR_REF (first_dr))
> by an alias type that is correct for all references in the whole
> access group.  With this patch we fall back to ptr_type_node, which
> can alias anything, if the group consists of different alias sets.
> 
> 
> Bootstrapped and reg-tested on x86_64-pc-linux-gnu.
> Is it OK for trunk and gcc-6-branch?

+/* Function get_group_alias_ptr_type.
+
+   Return the alias type for the group starting at FIRST_STMT
+   containing GROUP_SIZE elements.  */
+
+static tree
+get_group_alias_ptr_type (gimple *first_stmt, int group_size)
+{
+  struct data_reference *first_dr, *next_dr;
+  gimple *next_stmt;
+  int i;
+
+  first_dr = STMT_VINFO_DATA_REF (vinfo_for_stmt (first_stmt));
+  next_stmt = GROUP_NEXT_ELEMENT (vinfo_for_stmt (first_stmt));
+  for (i = 1; i < group_size && next_stmt; i++)
+    {


there is no need to pass in group_size, it's enough to walk
GROUP_NEXT_ELEMENT until it becomes NULL.

Ok with removing the redundant arg.

Thanks,
Richard.