AMDGPU: Fix not emitting code for exotic constructor types

[arsenm]

Summary

This was simply ignoring any entries that weren't direct function
calls. This really should have been erroring on anything
unexpected. We should be able to handle calling just about anything
these days, so just call anything.

[sameerds]

The change description says "should" in a couple of places. If we should error out on unexpected entries, then can it be handled in this change itself? The ctor/dtor bodies in the test look well-formed, but do they actually produce the correct code in the ISA? Should we have an llc test for the same or similar input?

[arsenm]

In D138841#3956178, @sameerds wrote:

The change description says "should" in a couple of places. If we should error out on unexpected entries, then can it be handled in this change itself? The ctor/dtor bodies in the test look well-formed, but do they actually produce the correct code in the ISA? Should we have an llc test for the same or similar input?

We shouldn't error, we certainly have all the handling for handling calls to anything. I can add an extra run line here to be sure

[arsenm]

Add llc run line

[arsenm]

ping

[arsenm]

41c96e94835df372ccdb6ad4df07b7bfaf257b51

llvm/lib/Target/AMDGPU/AMDGPUCtorDtorLowering.cpp

public:
 
   bool createInitOrFiniKernel(Module &M, StringRef GlobalName, bool IsCtor) {
     GlobalVariable *GV = M.getGlobalVariable(GlobalName);
     if (!GV || !GV->hasInitializer())
       return false;
     ConstantArray *GA = dyn_cast<ConstantArray>(GV->getInitializer());
     if (!GA || GA->getNumOperands() == 0)
       return false;
+
     Function *InitOrFiniKernel = createInitOrFiniKernelFunction(M, IsCtor);
     IRBuilder<> IRB(InitOrFiniKernel->getEntryBlock().getTerminator());
+
+    FunctionType *ConstructorTy = InitOrFiniKernel->getFunctionType();
+
     for (Value *V : GA->operands()) {
       auto *CS = cast<ConstantStruct>(V);
-      if (Function *F = dyn_cast<Function>(CS->getOperand(1))) {
-        FunctionCallee Ctor =
-            M.getOrInsertFunction(F->getName(), IRB.getVoidTy());
-        IRB.CreateCall(Ctor);
-      }
+      IRB.CreateCall(ConstructorTy, CS->getOperand(1));
     }
+
     appendToUsed(M, {InitOrFiniKernel});
     return true;
   }
 
   static char ID;
   AMDGPUCtorDtorLowering() : ModulePass(ID) {}
 };
 } // End anonymous namespace

llvm/test/CodeGen/AMDGPU/lower-ctor-dtor-constexpr-alias.ll

+; RUN: opt -S -mtriple=amdgcn-- -amdgpu-lower-ctor-dtor %s | FileCheck %s
+
+; Make sure we emit code for constructor entries that aren't direct
+; function calls.
+
+; Check a constructor that's an alias, and an integer literal.
[e-mail]_ctors = appending addrspace(1) global [2 x { i32, ptr, ptr }] [
+  { i32, ptr, ptr } { i32 1, ptr @foo.alias, i8* null },
+  { i32, ptr, ptr } { i32 1, ptr inttoptr (i64 4096 to ptr), i8* null }
+]
+
+; Check a constantexpr addrspacecast
[e-mail]_dtors = appending addrspace(1) global [1 x { i32, ptr, ptr }] [
+  { i32, ptr, ptr } { i32 1, ptr addrspacecast (ptr addrspace(1) @bar to ptr), i8* null }
+]
+
[e-mail] = hidden alias void (), ptr @foo
+
+;.
+; CHECK: @llvm.global_ctors = appending addrspace(1) global [2 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 1, ptr @foo.alias, ptr null }, { i32, ptr, ptr } { i32 1, ptr inttoptr (i64 4096 to ptr), ptr null }]
+; CHECK: @llvm.global_dtors = appending addrspace(1) global [1 x { i32, ptr, ptr }] [{ i32, ptr, ptr } { i32 1, ptr addrspacecast (ptr addrspace(1) @bar to ptr), ptr null }]
+; CHECK: @llvm.used = appending global [2 x ptr] [ptr @amdgcn.device.init, ptr @amdgcn.device.fini], section "llvm.metadata"
+; CHECK: @foo.alias = hidden alias void (), ptr @foo
+;.
+define void @foo() {
+; CHECK-LABEL: @foo(
+; CHECK-NEXT:    ret void
+;
+  ret void
+}
+
+define void @bar() addrspace(1) {
+; CHECK-LABEL: @bar(
+; CHECK-NEXT:    ret void
+;
+  ret void
+}
+
+; CHECK: define amdgpu_kernel void @amdgcn.device.init() #[[ATTR0:[0-9]+]] {
+; CHECK-NEXT: call void @foo.alias()
+; CHECK-NEXT: call void inttoptr (i64 4096 to ptr)()
+; CHECK-NEXT: ret void
+; CHECK-NEXT: }
+
+; CHECK: define amdgpu_kernel void @amdgcn.device.fini() #[[ATTR1:[0-9]+]] {
+; CHECK-NEXT: call void addrspacecast (ptr addrspace(1) @bar to ptr)()
+; CHECK-NEXT: ret void
+; CHECK-NEXT: }
+
+;.
+; CHECK: attributes #[[ATTR0]] = { "device-init" }
+; CHECK: attributes #[[ATTR1]] = { "device-fini" }
+;.