Add a new optimization pass: Stack Coloring, that merges disjoint static allocations (allocas). Allocas are known to be

disjoint if they are marked by disjoint lifetime markers (@llvm.lifetime.XXX intrinsics).

llvm-svn: 163299

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/Passes.cpp b/llvm/lib/CodeGen/Passes.cpp
index 9564b5dbe1e..a6dd5decbea 100644
--- a/llvm/lib/CodeGen/Passes.cpp
+++ b/llvm/lib/CodeGen/Passes.cpp
@@ -529,6 +529,10 @@ void TargetPassConfig::addMachineSSAOptimization() {
   // instructions dead.
   addPass(&OptimizePHIsID);
 
+  // This pass merges large allocas. StackSlotColoring is a different pass
+  // which merges spill slots.
+  addPass(&StackColoringID);
+
   // If the target requests it, assign local variables to stack slots relative
   // to one another and simplify frame index references where possible.
   addPass(&LocalStackSlotAllocationID);