8026940: assert(n->outcnt() != 0 || C->top() == n || n->is_Proj()) failed: No dead instructions after post-alloc
Summary: Remove input to junk phi if they also become dead during post_allocate_copy_removal
Reviewed-by: roland
--- a/hotspot/src/share/vm/opto/postaloc.cpp Wed Oct 23 20:20:03 2013 +0400
+++ b/hotspot/src/share/vm/opto/postaloc.cpp Fri Oct 25 10:13:40 2013 +0200
@@ -97,7 +97,8 @@
static bool expected_yanked_node(Node *old, Node *orig_old) {
// This code is expected only next original nodes:
// - load from constant table node which may have next data input nodes:
- // MachConstantBase, Phi, MachTemp, MachSpillCopy
+ // MachConstantBase, MachTemp, MachSpillCopy
+ // - Phi nodes that are considered Junk
// - load constant node which may have next data input nodes:
// MachTemp, MachSpillCopy
// - MachSpillCopy
@@ -112,7 +113,9 @@
return (old == orig_old);
} else if (old->is_MachTemp()) {
return orig_old->is_Con();
- } else if (old->is_Phi() || old->is_MachConstantBase()) {
+ } else if (old->is_Phi()) { // Junk phi's
+ return true;
+ } else if (old->is_MachConstantBase()) {
return (orig_old->is_Con() && orig_old->is_MachConstant());
}
return false;
@@ -522,11 +525,9 @@
u = u ? NodeSentinel : x; // Capture unique input, or NodeSentinel for 2nd input
}
if (u != NodeSentinel) { // Junk Phi. Remove
- block->remove_node(j--);
+ phi->replace_by(u);
+ j -= yank_if_dead(phi, block, &value, ®nd);
phi_dex--;
- _cfg.unmap_node_from_block(phi);
- phi->replace_by(u);
- phi->disconnect_inputs(NULL, C);
continue;
}
// Note that if value[pidx] exists, then we merged no new values here