[llvm] AMDGPU: Add baseline test for split/widen invariant loads (PR #168913)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm updated https://github.com/llvm/llvm-project/pull/168913

>From a8b806c3e6039b892f307ef3496e49a1d17aa8d5 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Thu, 20 Nov 2025 12:09:35 -0500
Subject: [PATCH] AMDGPU: Add baseline test for split/widen invariant loads

---
 .../CodeGen/AMDGPU/load-global-invariant.ll   | 77 +++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 llvm/test/CodeGen/AMDGPU/load-global-invariant.ll

diff --git a/llvm/test/CodeGen/AMDGPU/load-global-invariant.ll b/llvm/test/CodeGen/AMDGPU/load-global-invariant.ll
new file mode 100644
index 0000000000000..6cdadc5bab5fb
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/load-global-invariant.ll
@@ -0,0 +1,77 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 6
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 < %s | FileCheck %s
+
+; Check that invariant global loads are treated like constant
+; loads. The optnone disables the annotation of of amdgpu.noclobber.
+
+define amdgpu_kernel void @load_constant_v3i64(ptr addrspace(1) %dst, ptr addrspace(4) %src) #0 {
+; CHECK-LABEL: load_constant_v3i64:
+; CHECK:       ; %bb.0:
+; CHECK-NEXT:    v_mov_b32_e32 v4, 0
+; CHECK-NEXT:    s_load_dwordx2 s[4:5], s[8:9], 0x0
+; CHECK-NEXT:    s_load_dwordx2 s[6:7], s[8:9], 0x8
+; CHECK-NEXT:    s_waitcnt lgkmcnt(0)
+; CHECK-NEXT:    s_load_dwordx4 s[0:3], s[6:7], 0x0
+; CHECK-NEXT:    s_nop 0
+; CHECK-NEXT:    s_load_dwordx2 s[6:7], s[6:7], 0x10
+; CHECK-NEXT:    s_waitcnt lgkmcnt(0)
+; CHECK-NEXT:    v_mov_b32_e32 v0, s6
+; CHECK-NEXT:    v_mov_b32_e32 v1, s7
+; CHECK-NEXT:    global_store_dwordx2 v4, v[0:1], s[4:5] offset:16
+; CHECK-NEXT:    v_mov_b32_e32 v0, s0
+; CHECK-NEXT:    v_mov_b32_e32 v1, s1
+; CHECK-NEXT:    v_mov_b32_e32 v2, s2
+; CHECK-NEXT:    v_mov_b32_e32 v3, s3
+; CHECK-NEXT:    global_store_dwordx4 v4, v[0:3], s[4:5]
+; CHECK-NEXT:    s_endpgm
+  %ld = load <3 x i64>, ptr addrspace(4) %src, align 32
+  store <3 x i64> %ld, ptr addrspace(1) %dst, align 32
+  ret void
+}
+
+define amdgpu_kernel void @load_global_v3i64(ptr addrspace(1) %dst, ptr addrspace(1) %src) #0 {
+; CHECK-LABEL: load_global_v3i64:
+; CHECK:       ; %bb.0:
+; CHECK-NEXT:    v_mov_b32_e32 v6, 0
+; CHECK-NEXT:    s_load_dwordx2 s[0:1], s[8:9], 0x0
+; CHECK-NEXT:    s_load_dwordx2 s[2:3], s[8:9], 0x8
+; CHECK-NEXT:    s_waitcnt lgkmcnt(0)
+; CHECK-NEXT:    global_load_dwordx4 v[0:3], v6, s[2:3]
+; CHECK-NEXT:    global_load_dwordx2 v[4:5], v6, s[2:3] offset:16
+; CHECK-NEXT:    s_waitcnt vmcnt(0)
+; CHECK-NEXT:    global_store_dwordx2 v6, v[4:5], s[0:1] offset:16
+; CHECK-NEXT:    global_store_dwordx4 v6, v[0:3], s[0:1]
+; CHECK-NEXT:    s_endpgm
+  %ld = load <3 x i64>, ptr addrspace(1) %src, align 32
+  store <3 x i64> %ld, ptr addrspace(1) %dst, align 32
+  ret void
+}
+
+define amdgpu_kernel void @load_global_v3i64_invariant(ptr addrspace(1) %dst, ptr addrspace(1) %src) #0 {
+; CHECK-LABEL: load_global_v3i64_invariant:
+; CHECK:       ; %bb.0:
+; CHECK-NEXT:    v_mov_b32_e32 v4, 0
+; CHECK-NEXT:    s_load_dwordx2 s[4:5], s[8:9], 0x0
+; CHECK-NEXT:    s_load_dwordx2 s[6:7], s[8:9], 0x8
+; CHECK-NEXT:    s_waitcnt lgkmcnt(0)
+; CHECK-NEXT:    s_load_dwordx4 s[0:3], s[6:7], 0x0
+; CHECK-NEXT:    s_nop 0
+; CHECK-NEXT:    s_load_dwordx2 s[6:7], s[6:7], 0x10
+; CHECK-NEXT:    s_waitcnt lgkmcnt(0)
+; CHECK-NEXT:    v_mov_b32_e32 v0, s6
+; CHECK-NEXT:    v_mov_b32_e32 v1, s7
+; CHECK-NEXT:    global_store_dwordx2 v4, v[0:1], s[4:5] offset:16
+; CHECK-NEXT:    v_mov_b32_e32 v0, s0
+; CHECK-NEXT:    v_mov_b32_e32 v1, s1
+; CHECK-NEXT:    v_mov_b32_e32 v2, s2
+; CHECK-NEXT:    v_mov_b32_e32 v3, s3
+; CHECK-NEXT:    global_store_dwordx4 v4, v[0:3], s[4:5]
+; CHECK-NEXT:    s_endpgm
+  %ld = load <3 x i64>, ptr addrspace(1) %src, align 32, !invariant.load !0
+  store <3 x i64> %ld, ptr addrspace(1) %dst, align 32
+  ret void
+}
+
+attributes #0 = { noinline nounwind optnone }
+
+!0 = !{}