From 34534d0082c3aaf3e83056a3ac6fbb86c770d605 Mon Sep 17 00:00:00 2001
From: Krzysztof Parzyszek <kparzysz@codeaurora.org>
Date: Thu, 15 Feb 2018 15:47:53 +0000
Subject: [PATCH] [Hexagon] Fix lowering of formal arguments after r324737

Lowering of formal arguments needs to be aware of vararg functions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325255 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/Hexagon/HexagonISelLowering.cpp | 34 ++++++++++++++----------------
 test/CodeGen/Hexagon/vararg-formal.ll      | 12 +++++++++++
 2 files changed, 28 insertions(+), 18 deletions(-)
 create mode 100644 test/CodeGen/Hexagon/vararg-formal.ll

diff --git a/lib/Target/Hexagon/HexagonISelLowering.cpp b/lib/Target/Hexagon/HexagonISelLowering.cpp
index fd99a8fd0f0..e20c2875cb6 100644
--- a/lib/Target/Hexagon/HexagonISelLowering.cpp
+++ b/lib/Target/Hexagon/HexagonISelLowering.cpp
@@ -107,14 +107,20 @@ static cl::opt<int> MaxStoresPerMemsetOptSizeCL("max-store-memset-Os",
 namespace {
 
   class HexagonCCState : public CCState {
-    unsigned NumNamedVarArgParams;
+    unsigned NumNamedVarArgParams = 0;
 
   public:
     HexagonCCState(CallingConv::ID CC, bool IsVarArg, MachineFunction &MF,
                    SmallVectorImpl<CCValAssign> &locs, LLVMContext &C,
-                   int NumNamedVarArgParams)
-        : CCState(CC, IsVarArg, MF, locs, C),
-          NumNamedVarArgParams(NumNamedVarArgParams) {}
+                   const Function *Callee)
+        : CCState(CC, IsVarArg, MF, locs, C) {
+      // If a function has zero args and is a vararg function, that's
+      // disallowed so it must be an undeclared function.  Do not assume
+      // varargs if the callee is undefined.
+      if (Callee && Callee->isVarArg() &&
+          Callee->getFunctionType()->getNumParams() != 0)
+        NumNamedVarArgParams = Callee->getFunctionType()->getNumParams();
+    }
 
     unsigned getNumNamedVarArgParams() const { return NumNamedVarArgParams; }
   };
@@ -323,25 +329,17 @@ HexagonTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
   MachineFrameInfo &MFI = MF.getFrameInfo();
   auto PtrVT = getPointerTy(MF.getDataLayout());
 
-  // Check for varargs.
-  unsigned NumNamedVarArgParams = 0;
-
+  const Function *CalleeF = nullptr;
   if (GlobalAddressSDNode *GAN = dyn_cast<GlobalAddressSDNode>(Callee)) {
     const GlobalValue *GV = GAN->getGlobal();
     Callee = DAG.getTargetGlobalAddress(GV, dl, MVT::i32);
-    if (const Function* F = dyn_cast<Function>(GV)) {
-      // If a function has zero args and is a vararg function, that's
-      // disallowed so it must be an undeclared function.  Do not assume
-      // varargs if the callee is undefined.
-      if (F->isVarArg() && F->getFunctionType()->getNumParams() != 0)
-        NumNamedVarArgParams = F->getFunctionType()->getNumParams();
-    }
+    CalleeF = dyn_cast<Function>(GV);
   }
 
   // Analyze operands of the call, assigning locations to each operand.
   SmallVector<CCValAssign, 16> ArgLocs;
-  HexagonCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(),
-                        ArgLocs, *DAG.getContext(), NumNamedVarArgParams);
+  HexagonCCState CCInfo(CallConv, IsVarArg, MF, ArgLocs, *DAG.getContext(),
+                        CalleeF);
 
   if (Subtarget.useHVXOps())
     CCInfo.AnalyzeCallOperands(Outs, CC_Hexagon_HVX);
@@ -698,8 +696,8 @@ SDValue HexagonTargetLowering::LowerFormalArguments(
 
   // Assign locations to all of the incoming arguments.
   SmallVector<CCValAssign, 16> ArgLocs;
-  CCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs,
-                 *DAG.getContext());
+  HexagonCCState CCInfo(CallConv, IsVarArg, MF, ArgLocs, *DAG.getContext(),
+                        &MF.getFunction());
 
   if (Subtarget.useHVXOps())
     CCInfo.AnalyzeFormalArguments(Ins, CC_Hexagon_HVX);
diff --git a/test/CodeGen/Hexagon/vararg-formal.ll b/test/CodeGen/Hexagon/vararg-formal.ll
new file mode 100644
index 00000000000..6bba65fcab1
--- /dev/null
+++ b/test/CodeGen/Hexagon/vararg-formal.ll
@@ -0,0 +1,12 @@
+; RUN: llc -march=hexagon < %s | FileCheck %s
+
+; Make sure that the first formal argument is not loaded from memory.
+; CHECK-NOT: memw
+
+define i32 @fred(i32 %a0, ...) #0 {
+b1:
+  %v2 = add i32 %a0, 1
+  ret i32 %v2
+}
+
+attributes #0 = { nounwind }
-- 
2.11.0