AArch64: Safely handle the incoming sret call argument.

This adds a safe interface to the machine independent InputArg struct
for accessing the index of the original (IR-level) argument. When a
non-native return type is lowered, we generate the hidden
machine-level sret argument on-the-fly. Before this fix, we were
representing this argument as OrigArgIndex == 0, which is an outright
lie. In particular this crashed in the AArch64 backend where we
actually try to access the type of the original argument.

Now we use a sentinel value for machine arguments that have no
original argument index. AArch64, ARM, Mips, and PPC now check for this
case before accessing the original argument.

Fixes <rdar://19792160> Null pointer assertion in AArch64TargetLowering

llvm-svn: 229413

2 files changed, 4 insertions, 4 deletions

diff --git a/llvm/lib/Target/R600/R600ISelLowering.cpp b/llvm/lib/Target/R600/R600ISelLowering.cpp
index 70cc876cd93..38e17f13755 100644
--- a/llvm/lib/Target/R600/R600ISelLowering.cpp
+++ b/llvm/lib/Target/R600/R600ISelLowering.cpp
@@ -1693,7 +1693,7 @@ SDValue R600TargetLowering::LowerFormalArguments(
     // XXX - I think PartOffset should give you this, but it seems to give the
     // size of the register which isn't useful.
 
-    unsigned ValBase = ArgLocs[In.OrigArgIndex].getLocMemOffset();
+    unsigned ValBase = ArgLocs[In.getOrigArgIndex()].getLocMemOffset();
     unsigned PartOffset = VA.getLocMemOffset();
     unsigned Offset = 36 + VA.getLocMemOffset();
 
diff --git a/llvm/lib/Target/R600/SIISelLowering.cpp b/llvm/lib/Target/R600/SIISelLowering.cpp
index 452b54c3032..4fee32d7a47 100644
--- a/llvm/lib/Target/R600/SIISelLowering.cpp
+++ b/llvm/lib/Target/R600/SIISelLowering.cpp
@@ -446,7 +446,7 @@ SDValue SITargetLowering::LowerFormalArguments(
       // We REALLY want the ORIGINAL number of vertex elements here, e.g. a
       // three or five element vertex only needs three or five registers,
       // NOT four or eigth.
-      Type *ParamType = FType->getParamType(Arg.OrigArgIndex);
+      Type *ParamType = FType->getParamType(Arg.getOrigArgIndex());
       unsigned NumElements = ParamType->getVectorNumElements();
 
       for (unsigned j = 0; j != NumElements; ++j) {
@@ -529,7 +529,7 @@ SDValue SITargetLowering::LowerFormalArguments(
                                    Offset, Ins[i].Flags.isSExt());
 
       const PointerType *ParamTy =
-          dyn_cast<PointerType>(FType->getParamType(Ins[i].OrigArgIndex));
+        dyn_cast<PointerType>(FType->getParamType(Ins[i].getOrigArgIndex()));
       if (Subtarget->getGeneration() == AMDGPUSubtarget::SOUTHERN_ISLANDS &&
           ParamTy && ParamTy->getAddressSpace() == AMDGPUAS::LOCAL_ADDRESS) {
         // On SI local pointers are just offsets into LDS, so they are always
@@ -564,7 +564,7 @@ SDValue SITargetLowering::LowerFormalArguments(
     if (Arg.VT.isVector()) {
 
       // Build a vector from the registers
-      Type *ParamType = FType->getParamType(Arg.OrigArgIndex);
+      Type *ParamType = FType->getParamType(Arg.getOrigArgIndex());
       unsigned NumElements = ParamType->getVectorNumElements();
 
       SmallVector<SDValue, 4> Regs;