OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

sra: Fix corner case of total scalarization with virtual inheritance (PR 102505)

Browse Source 
PR 102505 is a situation where of SRA takes its initial top-level
access size from a get_ref_base_and_extent called on a COMPONENT_REF,
and thus derived frm the FIELD_DECL, which however does not include a
virtual base.  Total scalarization then goes on traversing the type,
which however has virtual base past the non-virtual bits, tricking SRA
to create sub-accesses outside of the supposedly encompassing
accesses, which in turn triggers the verifier within the pass.

The patch below fixes that by failing total scalarization when this
situation is detected.

gcc/ChangeLog:

2021-10-20  Martin Jambor  <mjambor@suse.cz>

	PR tree-optimization/102505
	* tree-sra.c (totally_scalarize_subtree): Check that the
	encountered field fits within the acces we would like to put it
	in.

gcc/testsuite/ChangeLog:

2021-10-20  Martin Jambor  <mjambor@suse.cz>

	PR tree-optimization/102505
	* g++.dg/torture/pr102505.C: New test.
This commit is contained in:
Martin Jambor 2021-10-21 14:26:45 +02:00
parent d6a3c0cfb8
commit 701ee06780
No known key found for this signature in database
GPG Key ID: BF63C1BC3FA43540
2 changed files with 17 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
gcc/testsuite/g++.dg/torture/pr102505.C Normal file
View File

@ -0,0 +1,15 @@
struct D { int i; int pad alignas(16); };
struct B : virtual D
{
int j =84;
int k =84;
};
struct C: B { };
int main()
{
C c;
if (c.j != 84 || c.k != 84)
__builtin_abort();
}

2
gcc/tree-sra.c
View File

@ -3288,6 +3288,8 @@ totally_scalarize_subtree (struct access *root)
continue;
HOST_WIDE_INT pos = root->offset + int_bit_position (fld);
if (pos + fsize > root->size)
return false;
enum total_sra_field_state
state = total_should_skip_creating_access (root,
&last_seen_sibling,