Re-prepared patch

Change-Id: Ibb8c0a57e15e0c8ac899fca828b0c2d9c0ff0dbd

releases/4.0.0/patches_external/07-Temporarily-disable-the-combination-on-b.patch

@@ -1,30 +1,25 @@
 #    Description                  : Temporarily disable the combination on bitcasts through PHI
 #    When Fixed in Open Source    : Needed till a cleaner solution is worked out.
-#    P4V CL                       : 679800(4.0.0)
 #    Category                     : Optimization
-#    Author                       : hliao
-#    Open Source Classification   : Internal Only
 #    Impact                       : Performance
-#    Failing Workload/Commandline : OCL luxmark3
 #    Notes                        : Under certain code pattern, that opt creates lots of redundant 
 #                                   PHI nodes which is hard to eliminated or coalesced and hence 
 #                                   increase register pressure significantly.
 
 diff -Naur --strip-trailing-cr a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp
---- a/lib/Transforms/InstCombine/InstCombineCasts.cpp	2017-10-23 09:53:04.931214744 -0400
-+++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp	2017-10-23 13:38:30.378684858 -0400
-@@ -1886,6 +1886,14 @@
+--- a/lib/Transforms/InstCombine/InstCombineCasts.cpp	2016-12-14 03:57:17.000000000 -0800
++++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp	2018-03-15 17:56:36.824041000 -0700
+@@ -1886,6 +1886,12 @@
  /// All the related PHI nodes can be replaced by new PHI nodes with type A.
  /// The uses of \p CI can be changed to the new PHI node corresponding to \p PN.
  Instruction *InstCombiner::optimizeBitCastFromPhi(CastInst &CI, PHINode *PN) {
-+  // Temporarily disable optimization of bitcasts through phi as it creates
-+  // significant amount of PHI nodes under certain patterns. As IGC has no
-+  // general register coalescing, these PHI nodes won't be coalesced. It
-+  // results in huge register pressure and slowdown lots of benchmarks
-+  // significantly.
-+  // https://jira01.devtools.intel.com/browse/IGC-1085 is created to track this
-+  // issue.
-+  return nullptr;
++ // Temporarily disable optimization of bitcasts through phi as it creates
++ // significant amount of PHI nodes under certain patterns. As IGC has no
++ // general register coalescing, these PHI nodes won't be coalesced. It
++ // results in huge register pressure and slowdown lots of benchmarks
++ // significantly.
++ return nullptr;
    // BitCast used by Store can be handled in InstCombineLoadStoreAlloca.cpp.
    if (hasStoreUsersOnly(CI))
      return nullptr;
+