[HotColdSplit] Relax requirement that the cold sink block be extractable

Relaxing this requirement creates opportunities to split code dominated
by an EH pad.

Tested on LNT+externals.

llvm-svn: 351483

1 files changed, 2 insertions, 5 deletions

diff --git a/llvm/lib/Transforms/IPO/HotColdSplitting.cpp b/llvm/lib/Transforms/IPO/HotColdSplitting.cpp
index d0f3fdf0c60..2cf8af35401 100644
--- a/llvm/lib/Transforms/IPO/HotColdSplitting.cpp
+++ b/llvm/lib/Transforms/IPO/HotColdSplitting.cpp
@@ -391,7 +391,8 @@ public:
 
     // Add SinkBB to the cold region. It's considered as an entry point before
     // any sink-successor blocks.
-    addBlockToRegion(&SinkBB, SinkScore);
+    if (mayExtractBlock(SinkBB))
+      addBlockToRegion(&SinkBB, SinkScore);
 
     // Find all successors of SinkBB dominated by SinkBB using DFS.
     auto SuccIt = ++df_begin(&SinkBB);
@@ -486,10 +487,6 @@ bool HotColdSplitting::outlineColdRegions(Function &F, ProfileSummaryInfo &PSI,
 
   // Find all cold regions.
   for (BasicBlock *BB : RPOT) {
-    // Skip blocks which can't be outlined.
-    if (!mayExtractBlock(*BB))
-      continue;
-
     // This block is already part of some outlining region.
     if (ColdBlocks.count(BB))
       continue;