[llvm] [AMDGPU][LowerModuleLDS] Handle non-dynlds zero sized type (PR #84742)

[Pierre van Houtryve via llvm-commits]

https://github.com/Pierre-vh updated https://github.com/llvm/llvm-project/pull/84742

>From 7700e6ccfe398d862c4afde25c9bbac64718e0aa Mon Sep 17 00:00:00 2001
From: pvanhout <pierre.vanhoutryve at amd.com>
Date: Wed, 20 Mar 2024 10:09:57 +0100
Subject: [PATCH] [AMDGPU][LowerModuleLDS] Avoid crash on zero-sized types

---
 llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp    |  4 ++++
 .../CodeGen/AMDGPU/lower-module-lds-zero-size-type.ll  | 10 ++++++++++
 2 files changed, 14 insertions(+)
 create mode 100644 llvm/test/CodeGen/AMDGPU/lower-module-lds-zero-size-type.ll

diff --git a/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp b/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp
index b85cb26fdc9565..b18f820bd0b728 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp
@@ -1398,6 +1398,10 @@ class AMDGPULowerModuleLDS {
           LDSVarsToTransform.begin(), LDSVarsToTransform.end()));
 
       for (GlobalVariable *GV : Sorted) {
+        if (DL.getTypeAllocSize(GV->getValueType()) == 0)
+          report_fatal_error("cannot lower LDS '" + GV->getName() +
+                             "' because it has a zero-sized type");
+
         OptimizedStructLayoutField F(GV,
                                      DL.getTypeAllocSize(GV->getValueType()),
                                      AMDGPU::getAlign(DL, GV));
diff --git a/llvm/test/CodeGen/AMDGPU/lower-module-lds-zero-size-type.ll b/llvm/test/CodeGen/AMDGPU/lower-module-lds-zero-size-type.ll
new file mode 100644
index 00000000000000..9a618ec07cced3
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/lower-module-lds-zero-size-type.ll
@@ -0,0 +1,10 @@
+; RUN: not --crash opt -S -mtriple=amdgcn-- -amdgpu-lower-module-lds --amdgpu-lower-module-lds-strategy=module < %s 2>&1 | FileCheck %s
+; RUN: not --crash opt -S -mtriple=amdgcn-- -passes=amdgpu-lower-module-lds --amdgpu-lower-module-lds-strategy=module < %s 2>&1 | FileCheck %s
+
+; CHECK: LLVM ERROR: cannot lower LDS 'var0' because it has a zero-sized type
+ at var0 = internal addrspace(3) global [0 x float] poison, align 4
+
+define amdgpu_kernel void @kernel() {
+  load float, ptr addrspace(3) @var0
+  ret void
+}