[IR][SDAG] Remove lifetime size handling from SDAG (#150944)

Split out from https://github.com/llvm/llvm-project/pull/150248:

Specify that the argument of lifetime.start/lifetime.end is ignored and
will be removed in the future.

Remove lifetime size handling from SDAG. The size was previously
discarded during isel, so was always ignored for stack coloring anyway.
Where necessary, obtain the size of the full frame index.

1 files changed, 1 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 6eca7b7..306e068 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -7598,8 +7598,6 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
     if (TM.getOptLevel() == CodeGenOptLevel::None)
       return;
 
-    const int64_t ObjectSize =
-        cast<ConstantInt>(I.getArgOperand(0))->getSExtValue();
     const AllocaInst *LifetimeObject = cast<AllocaInst>(I.getArgOperand(1));
 
     // First check that the Alloca is static, otherwise it won't have a
@@ -7609,7 +7607,7 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
       return;
 
     const int FrameIndex = SI->second;
-    Res = DAG.getLifetimeNode(IsStart, sdl, getRoot(), FrameIndex, ObjectSize);
+    Res = DAG.getLifetimeNode(IsStart, sdl, getRoot(), FrameIndex);
     DAG.setRoot(Res);
     return;
   }