From a908edd6eef67edcf48d2cf0f4f9456705037976 Mon Sep 17 00:00:00 2001
From: roland <unknown>
Date: Thu, 11 Feb 2016 12:42:12 +0100
Subject: [PATCH] 8149543: range check CastII nodes should not be split through
 Phi Summary: splitting range check CastIIs through loop induction Phi
 prevents further optimizations Reviewed-by: kvn, mcberg

---
 src/share/vm/opto/loopopts.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/share/vm/opto/loopopts.cpp b/src/share/vm/opto/loopopts.cpp
index 062daec66..e19f35a0a 100644
--- a/src/share/vm/opto/loopopts.cpp
+++ b/src/share/vm/opto/loopopts.cpp
@@ -43,6 +43,14 @@ Node *PhaseIdealLoop::split_thru_phi( Node *n, Node *region, int policy ) {
     return NULL;
   }
 
+  // Splitting range check CastIIs through a loop induction Phi can
+  // cause new Phis to be created that are left unrelated to the loop
+  // induction Phi and prevent optimizations (vectorization)
+  if (n->Opcode() == Op_CastII && n->as_CastII()->has_range_check() &&
+      region->is_CountedLoop() && n->in(1) == region->as_CountedLoop()->phi()) {
+    return NULL;
+  }
+
   int wins = 0;
   assert(!n->is_CFG(), "");
   assert(region->is_Region(), "");
-- 
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