AMDGPU/R600: Use correct number of vector elements when lowering private loads

[jvesely]

Summary

fixes piglit:

multiple-stack-objects

[arsenm]

lib/Target/AMDGPU/R600ISelLowering.cpp

1664

Why is this being hit for > 4 elements? Those should have been split up during type legalization already by the time it reaches here

[jvesely]

lib/Target/AMDGPU/R600ISelLowering.cpp

1664

You're right, it's not. I realized it during testing. Keeping SDValue [4] and using makeArrayRef(Loads, NumElementVT) works too. SmallVector seemed a bit more robust.

[jvesely]

lib/Target/AMDGPU/R600ISelLowering.cpp

1664

would you prefer if I changed the approach to makeArrayRef, or removed the v16 tests from this patch?

[jvesely]

adapt tests to changed MaxPrivateElementSize (r269145)

[arsenm]

lib/Target/AMDGPU/R600ISelLowering.cpp

1664

More tests is good. makeArrayRef would probably be better

[jvesely]

switch to makeArrayRef

another rebase

[arsenm]

LGTM

lib/Target/AMDGPU/R600ISelLowering.cpp

const AMDGPUFrameLowering *TFL =
       static_cast<const AMDGPUFrameLowering *>(Subtarget->getFrameLowering());
   unsigned StackWidth = TFL->getStackWidth(MF);
 
   Ptr = stackPtrToRegIndex(Ptr, StackWidth, DAG);
 
   if (VT.isVector()) {
     unsigned NumElemVT = VT.getVectorNumElements();
     EVT ElemVT = VT.getVectorElementType();
-    SDValue Loads[4];
+    SmallVector<SDValue, 4> Loads(NumElemVT);
 
     assert(NumElemVT >= StackWidth && "Stack width cannot be greater than "
                                       "vector width in load");
 
     for (unsigned i = 0; i < NumElemVT; ++i) {
       unsigned Channel, PtrIncr;
       getStackAddress(StackWidth, i, Channel, PtrIncr);
       Ptr = DAG.getNode(ISD::ADD, DL, MVT::i32, Ptr,
                         DAG.getConstant(PtrIncr, DL, MVT::i32));
       Loads[i] = DAG.getNode(AMDGPUISD::REGISTER_LOAD, DL, ElemVT,
                              Chain, Ptr,
                              DAG.getTargetConstant(Channel, DL, MVT::i32),
                              Op.getOperand(2));
     }
-    for (unsigned i = NumElemVT; i < 4; ++i) {
-      Loads[i] = DAG.getUNDEF(ElemVT);
-    }
-    EVT TargetVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, 4);
+    EVT TargetVT = EVT::getVectorVT(*DAG.getContext(), ElemVT, NumElemVT);
     LoweredLoad = DAG.getBuildVector(TargetVT, DL, Loads);
   } else {
     LoweredLoad = DAG.getNode(AMDGPUISD::REGISTER_LOAD, DL, VT,
                               Chain, Ptr,
                               DAG.getTargetConstant(0, DL, MVT::i32), // Channel
                               Op.getOperand(2));
   }
 

test/CodeGen/AMDGPU/amdgpu.private-memory.ll

define void @ptrtoint(i32 addrspace(1)* %out, i32 %a, i32 %b) {
   store i32 %tmp5, i32 addrspace(1)* %out
   ret void
 }
 
 ; HSAOPT: !0 = !{}
 ; HSAOPT: !1 = !{i32 0, i32 2048}
 
 ; NOHSAOPT: !0 = !{i32 0, i32 2048}
+
+
+; FUNC-LABEL: v16i32_stack:
+
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+
+; SI: buffer_load_dwordx4
+; SI: buffer_load_dwordx4
+; SI: buffer_load_dwordx4
+; SI: buffer_load_dwordx4
+
+define void @v16i32_stack(<16 x i32> addrspace(1)* %out, i32 %a) {
+  %alloca = alloca [2 x <16 x i32>]
+  %tmp0 = getelementptr [2 x <16 x i32>], [2 x <16 x i32>]* %alloca, i32 0, i32 %a
+  %tmp5 = load <16 x i32>, <16 x i32>* %tmp0
+  store <16 x i32> %tmp5, <16 x i32> addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: v16float_stack:
+
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+; R600: MOVA_INT
+
+; SI: buffer_load_dwordx4
+; SI: buffer_load_dwordx4
+; SI: buffer_load_dwordx4
+; SI: buffer_load_dwordx4
+
+define void @v16float_stack(<16 x float> addrspace(1)* %out, i32 %a) {
+  %alloca = alloca [2 x <16 x float>]
+  %tmp0 = getelementptr [2 x <16 x float>], [2 x <16 x float>]* %alloca, i32 0, i32 %a
+  %tmp5 = load <16 x float>, <16 x float>* %tmp0
+  store <16 x float> %tmp5, <16 x float> addrspace(1)* %out
+  ret void
+}
+
+; FUNC-LABEL: v2float_stack:
+
+; R600: MOVA_INT
+; R600: MOVA_INT
+
+; SI: buffer_load_dwordx2
+
+define void @v2float_stack(<2 x float> addrspace(1)* %out, i32 %a) {
+  %alloca = alloca [16 x <2 x float>]
+  %tmp0 = getelementptr [16 x <2 x float>], [16 x <2 x float>]* %alloca, i32 0, i32 %a
+  %tmp5 = load <2 x float>, <2 x float>* %tmp0
+  store <2 x float> %tmp5, <2 x float> addrspace(1)* %out
+  ret void
+}