[llvm] 9e4ef0d - [CodeGen][SDAG] Track returntwice in lowering info (#92640)

[via llvm-commits]

Author: aengelke
Date: 2024-05-19T16:39:19+02:00
New Revision: 9e4ef0dee18c0c99325e8d56f16c149020e89d37

URL: https://github.com/llvm/llvm-project/commit/9e4ef0dee18c0c99325e8d56f16c149020e89d37
DIFF: https://github.com/llvm/llvm-project/commit/9e4ef0dee18c0c99325e8d56f16c149020e89d37.diff

LOG: [CodeGen][SDAG] Track returntwice in lowering info (#92640)

This saves an extra iteration over the all instructions of the function.

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
    llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp

Removed: 
    


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diff  --git a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index 35f840201e4ba..de22d230b1c32 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -214,6 +214,10 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
           if (CI->isMustTailCall() && Fn->isVarArg())
             MF->getFrameInfo().setHasMustTailInVarArgFunc(true);
         }
+
+        // Determine if there is a call to setjmp in the machine function.
+        if (Call->hasFnAttr(Attribute::ReturnsTwice))
+          MF->setExposesReturnsTwice(true);
       }
 
       // Mark values used outside their block as exported, by allocating

diff  --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index b5694c955b8c8..8addaf1ae3e54 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -680,9 +680,6 @@ bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
     }
   }
 
-  // Determine if there is a call to setjmp in the machine function.
-  MF->setExposesReturnsTwice(Fn.callsFunctionThatReturnsTwice());
-
   // Determine if floating point is used for msvc
   computeUsesMSVCFloatingPoint(TM.getTargetTriple(), Fn, MF->getMMI());