[CodeGen] Move IsFixed into ArgFlags (NFCI) (#152319)

The information whether a specific argument is vararg or fixed is
currently stored separately from all the other argument information in
ArgFlags. This means that it is not accessible from CCAssign, and
backends have developed all kinds of workarounds for how they can access
it after all.

Move this information to ArgFlags to make it directly available in all
relevant places.

I've opted to invert this and store it as IsVarArg, as I think that both
makes the meaning more obvious and provides for a better default (which
is IsVarArg=false).

1 files changed, 8 insertions, 8 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index d0815e9..868e2f4 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -2273,9 +2273,8 @@ void SelectionDAGBuilder::visitRet(const ReturnInst &I) {
           Flags.setNoExt();
 
         for (unsigned i = 0; i < NumParts; ++i) {
-          Outs.push_back(ISD::OutputArg(Flags,
-                                        Parts[i].getValueType().getSimpleVT(),
-                                        VT, /*isfixed=*/true, 0, 0));
+          Outs.push_back(ISD::OutputArg(
+              Flags, Parts[i].getValueType().getSimpleVT(), VT, 0, 0));
           OutVals.push_back(Parts[i]);
         }
       }
@@ -2291,9 +2290,9 @@ void SelectionDAGBuilder::visitRet(const ReturnInst &I) {
     assert(SwiftError.getFunctionArg() && "Need a swift error argument");
     ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
     Flags.setSwiftError();
-    Outs.push_back(ISD::OutputArg(
-        Flags, /*vt=*/TLI.getPointerTy(DL), /*argvt=*/EVT(TLI.getPointerTy(DL)),
-        /*isfixed=*/true, /*origidx=*/1, /*partOffs=*/0));
+    Outs.push_back(ISD::OutputArg(Flags, /*vt=*/TLI.getPointerTy(DL),
+                                  /*argvt=*/EVT(TLI.getPointerTy(DL)),
+                                  /*origidx=*/1, /*partOffs=*/0));
     // Create SDNode for the swifterror virtual register.
     OutVals.push_back(
         DAG.getRegister(SwiftError.getOrCreateVRegUseAt(
@@ -11124,6 +11123,8 @@ TargetLowering::LowerCallTo(TargetLowering::CallLoweringInfo &CLI) const {
       const Align OriginalAlignment(getABIAlignmentForCallingConv(ArgTy, DL));
       Flags.setOrigAlign(OriginalAlignment);
 
+      if (i >= CLI.NumFixedArgs)
+        Flags.setVarArg();
       if (Args[i].Ty->isPointerTy()) {
         Flags.setPointer();
         Flags.setPointerAddrSpace(
@@ -11246,8 +11247,7 @@ TargetLowering::LowerCallTo(TargetLowering::CallLoweringInfo &CLI) const {
         // For scalable vectors the scalable part is currently handled
         // by individual targets, so we just use the known minimum size here.
         ISD::OutputArg MyFlags(
-            Flags, Parts[j].getValueType().getSimpleVT(), VT,
-            i < CLI.NumFixedArgs, i,
+            Flags, Parts[j].getValueType().getSimpleVT(), VT, i,
             j * Parts[j].getValueType().getStoreSize().getKnownMinValue());
         if (NumParts > 1 && j == 0)
           MyFlags.Flags.setSplit();