procyberian/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Kill second order relations in the path solver.

Browse source 
My upcoming work replacing the VRP threaders with a fully resolving
backward threader has tripped over various corner cases in the path
sensitive relation oracle.  This patch kills second order relations when
we kill a relation.

Tested on x86-64 and ppc64le Linux.

Co-authored-by: Andrew MacLeod <amacleod@redhat.com>

gcc/ChangeLog:

	* value-relation.cc (path_oracle::killing_def): Kill second
	order relations.
This commit is contained in:
Aldy Hernandez 2021-10-27 16:24:53 +02:00
parent a1957c9755
commit 9f4edfc1fb
1 changed files with 20 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

21
gcc/value-relation.cc
View file

@ -1297,8 +1297,9 @@ path_oracle::killing_def (tree ssa)
fprintf (dump_file, "\n");
}
unsigned v = SSA_NAME_VERSION (ssa);
bitmap b = BITMAP_ALLOC (&m_bitmaps);
bitmap_set_bit (b, SSA_NAME_VERSION (ssa));
bitmap_set_bit (b, v);
equiv_chain *ptr = (equiv_chain *) obstack_alloc (&m_chain_obstack,
sizeof (equiv_chain));
ptr->m_names = b;
@ -1306,6 +1307,24 @@ path_oracle::killing_def (tree ssa)
ptr->m_next = m_equiv.m_next;
m_equiv.m_next = ptr;
bitmap_ior_into (m_equiv.m_names, b);
// Walk the relation list an remove SSA from any relations.
if (!bitmap_bit_p (m_relations.m_names, v))
return;
bitmap_clear_bit (m_relations.m_names, v);
relation_chain **prev = &(m_relations.m_head);
relation_chain *next = NULL;
for (relation_chain *ptr = m_relations.m_head; ptr; ptr = next)
{
gcc_checking_assert (*prev == ptr);
next = ptr->m_next;
if (SSA_NAME_VERSION (ptr->op1 ()) == v
|| SSA_NAME_VERSION (ptr->op2 ()) == v)
*prev = ptr->m_next;
else
prev = &(ptr->m_next);
}
}
// Register relation K between SSA1 and SSA2, resolving unknowns by