AMDGPU/SI: Remove assert from AMDGPUOpenCLImageTypeLowering pass

[• tstellarAMD]

Summary

Instead of asserting when the kernel metadata is different than we expect,
we should just skip lowering that function. This fixes assertion
failures with OpenCL argument metadata from older LLVM releases.

[arsenm]

lib/Target/AMDGPU/AMDGPUOpenCLImageTypeLoweringPass.cpp

100

If you're bothering to check this should probably be a checked dyn_cast

[• tstellarAMD]

Use dyn_cast()

[arsenm]

LGTM

lib/Target/AMDGPU/AMDGPUOpenCLImageTypeLoweringPass.cpp

GetFunctionFromMDNode(MDNode *Node) {
   // Sanity checks.
   size_t ExpectNumArgNodeOps = F->arg_size() + 1;
   for (size_t i = 0; i < NumKernelArgMDNodes; ++i) {
     MDNode *ArgNode = dyn_cast_or_null<MDNode>(Node->getOperand(i + 1));
     if (ArgNode->getNumOperands() != ExpectNumArgNodeOps)
       return nullptr;
     if (!ArgNode->getOperand(0))
       return nullptr;
-    assert(cast<MDString>(ArgNode->getOperand(0))->getString() ==
-           KernelArgMDNodeNames[i] && "Wrong kernel arg metadata name");
+
+    // FIXME: It should be possible to do image lowering when some metadata
+    // args missing or not in the expected order.
+    MDString *StringNode = dyn_cast<MDString>(ArgNode->getOperand(0));
+    if (!StringNode || StringNode->getString() != KernelArgMDNodeNames[i])
+      return nullptr;
   }
 
   return F;
 }
 
 static StringRef
 AccessQualFromMD(MDNode *KernelMDNode, unsigned ArgIdx) {
   MDNode *ArgAQNode = cast<MDNode>(KernelMDNode->getOperand(2));

test/CodeGen/AMDGPU/opencl-image-metadata.ll

+; RUN: llc < %s -march=r600 -mcpu=redwood | FileCheck --check-prefix=EG --check-prefix=FUNC %s
+; RUN: llc < %s -march=amdgcn -mcpu=SI -verify-machineinstrs | FileCheck --check-prefix=SI --check-prefix=FUNC %s
+
+; Make sure the OpenCL Image lowering pass doesn't crash when argument metadata
+; is not in expected order.
+
+; EG: CF_END
+; SI: s_endpgm
+define void @kernel(i32 addrspace(1)* %out) {
+entry:
+  store i32 0, i32 addrspace(1)* %out
+  ret void
+}
+
+attributes #3 = { nounwind }
+
+!opencl.kernels = !{!0}
+
+!0 = !{void (i32 addrspace(1)*)* @kernel, !1, !2, !3, !4, !5}
+!1 = !{!"kernel_arg_addr_space", i32 0}
+!2 = !{!"kernel_arg_access_qual", !"none"}
+!3 = !{!"kernel_arg_type", !"int*"}
+!4 = !{!"kernel_arg_type_qual", !""}
+!5 = !{!"kernel_arg_name", !""}