xref: /llvm-project/clang/test/CodeGenCUDA/unused-global-var.cu (revision 4e5d9c88033f1fc5d5206a02d8303bc6de43cf2b)
1 // REQUIRES: amdgpu-registered-target
2 // RUN: %clang_cc1 -triple amdgcn-amd-amdhsa -fcuda-is-device -x hip %s \
3 // RUN:   -std=c++11 -O3 -mllvm -amdgpu-internalize-symbols -emit-llvm -o - \
4 // RUN:   -target-cpu gfx906 | FileCheck %s
5 // RUN: %clang_cc1 -triple amdgcn-amd-amdhsa -fcuda-is-device -x hip %s \
6 // RUN:   -std=c++11 -O3 -mllvm -amdgpu-internalize-symbols -emit-llvm -o - \
7 // RUN:   -target-cpu gfx906 | FileCheck -check-prefix=NEGCHK %s
8 
9 #include "Inputs/cuda.h"
10 
11 // AMDGPU internalize unused global variables for whole-program compilation
12 // (-fno-gpu-rdc for each TU, or -fgpu-rdc for LTO), which are then
13 // eliminated by global DCE. If there are invisible unused address space casts
14 // for global variables, these dead users need to be eliminated by global
15 // DCE before internalization. This test makes sure unused global variables
16 // are eliminated.
17 
18 // CHECK-DAG: @v1
19 __device__ int v1;
20 
21 // CHECK-DAG: @v2
22 __constant__ int v2;
23 
24 // Check unused device/constant variables are eliminated.
25 
26 // NEGCHK-NOT: @_ZL2v3
27 constexpr int v3 = 1;
28 
29 // Check managed variables are always kept.
30 
31 // CHECK-DAG: @v4
32 __managed__ int v4;
33 
34 // Check used device/constant variables are not eliminated.
35 // CHECK-DAG: @u1
36 __device__ int u1;
37 
38 // CHECK-DAG: @u2
39 __constant__ int u2;
40 
41 // Check u3 is kept because its address is taken.
42 // CHECK-DAG: @_ZL2u3
43 constexpr int u3 = 2;
44 
45 // Check u4 is not kept because it is not ODR-use.
46 // NEGCHK-NOT: @_ZL2u4
47 constexpr int u4 = 3;
48 
49 __device__ int fun1(const int& x);
50 
kern1(int * x)51 __global__ void kern1(int *x) {
52   *x = u1 + u2 + fun1(u3) + u4;
53 }
54