AMDGPU/GlobalISel: Fix argument lowering for vectors of pointers

When these arguments are broken down by the EVT based callbacks, the
pointer information is lost. Hack around this by coercing the register
types to be the expected pointer element type when building the
remerge operations.

1 files changed, 18 insertions, 2 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUCallLowering.cpp b/llvm/lib/Target/AMDGPU/AMDGPUCallLowering.cpp
index f0650344320..c657ca71bfd 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUCallLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUCallLowering.cpp
@@ -516,11 +516,26 @@ static void packSplitRegsToOrigType(MachineIRBuilder &B,
     return;
   }
 
+  MachineRegisterInfo &MRI = *B.getMRI();
+
   assert(LLTy.isVector() && !PartLLT.isVector());
 
   LLT DstEltTy = LLTy.getElementType();
+
+  // Pointer information was discarded. We'll need to coerce some register types
+  // to avoid violating type constraints.
+  LLT RealDstEltTy = MRI.getType(OrigRegs[0]).getElementType();
+
+  assert(DstEltTy.getSizeInBits() == RealDstEltTy.getSizeInBits());
+
   if (DstEltTy == PartLLT) {
     // Vector was trivially scalarized.
+
+    if (RealDstEltTy.isPointer()) {
+      for (Register Reg : Regs)
+        MRI.setType(Reg, RealDstEltTy);
+    }
+
     B.buildBuildVector(OrigRegs[0], Regs);
   } else if (DstEltTy.getSizeInBits() > PartLLT.getSizeInBits()) {
     // Deal with vector with 64-bit elements decomposed to 32-bit
@@ -531,8 +546,9 @@ static void packSplitRegsToOrigType(MachineIRBuilder &B,
     assert(DstEltTy.getSizeInBits() % PartLLT.getSizeInBits() == 0);
 
     for (int I = 0, NumElts = LLTy.getNumElements(); I != NumElts; ++I)  {
-      auto Merge = B.buildMerge(DstEltTy,
-                                         Regs.take_front(PartsPerElt));
+      auto Merge = B.buildMerge(RealDstEltTy, Regs.take_front(PartsPerElt));
+      // Fix the type in case this is really a vector of pointers.
+      MRI.setType(Merge.getReg(0), RealDstEltTy);
       EltMerges.push_back(Merge.getReg(0));
       Regs = Regs.drop_front(PartsPerElt);
     }