The following fixes PR61452 - when keeping a lattice value at
VARYING we shouldn't adjust the lattice ->expr or ->has_constants.
Bootstrap and regtest pending on x86_64-unknown-linux-gnu.
Richard.
2014-06-10 Richard Biener <rguent...@suse.de>
PR tree-optimization/61452
* tree-ssa-sccvn.c (visit_phi): Remove pointless setting of
expr and has_constants in case we found a leader.
* gcc.dg/torture/pr61452.c: New testcase.
Index: gcc/tree-ssa-sccvn.c
===================================================================
*** gcc/tree-ssa-sccvn.c (revision 211403)
--- gcc/tree-ssa-sccvn.c (working copy)
*************** visit_phi (gimple phi)
*** 3140,3174 ****
/* If all value numbered to the same value, the phi node has that
value. */
if (allsame)
! {
! if (is_gimple_min_invariant (sameval))
! {
! VN_INFO (PHI_RESULT (phi))->has_constants = true;
! if (sameval != VN_TOP)
! VN_INFO (PHI_RESULT (phi))->expr = sameval;
! }
! else
! {
! VN_INFO (PHI_RESULT (phi))->has_constants = false;
! if (sameval != VN_TOP)
! VN_INFO (PHI_RESULT (phi))->expr = sameval;
! }
!
! if (TREE_CODE (sameval) == SSA_NAME)
! return visit_copy (PHI_RESULT (phi), sameval);
!
! return set_ssa_val_to (PHI_RESULT (phi), sameval);
! }
/* Otherwise, see if it is equivalent to a phi node in this block. */
result = vn_phi_lookup (phi);
if (result)
! {
! if (TREE_CODE (result) == SSA_NAME)
! changed = visit_copy (PHI_RESULT (phi), result);
! else
! changed = set_ssa_val_to (PHI_RESULT (phi), result);
! }
else
{
vn_phi_insert (phi, PHI_RESULT (phi));
--- 3140,3151 ----
/* If all value numbered to the same value, the phi node has that
value. */
if (allsame)
! return set_ssa_val_to (PHI_RESULT (phi), sameval);
/* Otherwise, see if it is equivalent to a phi node in this block. */
result = vn_phi_lookup (phi);
if (result)
! changed = set_ssa_val_to (PHI_RESULT (phi), result);
else
{
vn_phi_insert (phi, PHI_RESULT (phi));
Index: gcc/testsuite/gcc.dg/torture/pr61452.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr61452.c (revision 0)
--- gcc/testsuite/gcc.dg/torture/pr61452.c (working copy)
***************
*** 0 ****
--- 1,31 ----
+ /* { dg-do run } */
+
+ int a, b;
+ short c, d;
+ char e, f;
+
+ int
+ fn1 (int p1, char p2)
+ {
+ return p1 || p2 ? 0 : p2;
+ }
+
+ void
+ fn2 ()
+ {
+ for (; a;)
+ {
+ int g;
+ g = c = e;
+ for (; a;)
+ b = fn1 (g = d = e, g);
+ f = g;
+ }
+ }
+
+ int
+ main ()
+ {
+ fn2 ();
+ return 0;
+ }
