AMDGPU: Make llvm.amdgcn.make.buffer.rsrc propagate poison (#141913)

Author: arsenm

llvm/lib/Target/AMDGPU/AMDGPUInstCombineIntrinsic.cpp

@@ -1527,6 +1527,12 @@ GCNTTIImpl::instCombineIntrinsic(InstCombiner &IC, IntrinsicInst &II) const {
       return IC.replaceInstUsesWith(II, ConstantInt::getFalse(II.getType()));
     break;
   }
+  case Intrinsic::amdgcn_make_buffer_rsrc: {
+    Value *Src = II.getArgOperand(0);
+    if (isa<PoisonValue>(Src))
+      return IC.replaceInstUsesWith(II, PoisonValue::get(II.getType()));
+    return std::nullopt;
+  }
   case Intrinsic::amdgcn_raw_buffer_store_format:
   case Intrinsic::amdgcn_struct_buffer_store_format:
   case Intrinsic::amdgcn_raw_tbuffer_store:

llvm/test/Transforms/InstCombine/AMDGPU/amdgcn-intrinsics.ll

@@ -6520,3 +6520,24 @@ define amdgpu_kernel void @ds_bpermute_uniform_lane(ptr addrspace(1) %out, i32 %
   store i32 %v, ptr addrspace(1) %out
   ret void
 }
+
+; --------------------------------------------------------------------
+; llvm.amdgcn.make.buffer.rsrc.p8
+; --------------------------------------------------------------------
+
+define ptr addrspace(8) @make_buffer_rsrc_poison() {
+; CHECK-LABEL: @make_buffer_rsrc_poison(
+; CHECK-NEXT:    ret ptr addrspace(8) poison
+;
+  %rsrc = call ptr addrspace(8) @llvm.amdgcn.make.buffer.rsrc.p8.p1(ptr addrspace(1) poison, i16 0, i32 1234, i32 5678)
+  ret ptr addrspace(8) %rsrc
+}
+
+define ptr addrspace(8) @make_buffer_rsrc_undef() {
+; CHECK-LABEL: @make_buffer_rsrc_undef(
+; CHECK-NEXT:    [[RSRC:%.*]] = call ptr addrspace(8) @llvm.amdgcn.make.buffer.rsrc.p8.p1(ptr addrspace(1) undef, i16 0, i32 1234, i32 5678)
+; CHECK-NEXT:    ret ptr addrspace(8) [[RSRC]]
+;
+  %rsrc = call ptr addrspace(8) @llvm.amdgcn.make.buffer.rsrc.p8.p1(ptr addrspace(1) undef, i16 0, i32 1234, i32 5678)
+  ret ptr addrspace(8) %rsrc
+}