[llvm] [Verifier][AMDGPU] Restrict targets for chain calling convention. (PR #157469)

[via llvm-commits]

https://github.com/jofrn created https://github.com/llvm/llvm-project/pull/157469

The chain calling convention is invalid in particular situations like being on an architecture it cannot compile to.

>From d2e4f3f2c4e32bc4f192271537c0eaa2c133b696 Mon Sep 17 00:00:00 2001
From: jofrn <jofernau at amd.com>
Date: Mon, 8 Sep 2025 10:15:20 -0400
Subject: [PATCH] [Verifier][AMDGPU] The chain calling convention is invalid in
 particular situations like being on an architecture it cannot compile to.

---
 llvm/lib/IR/Verifier.cpp                               | 10 ++++++++--
 .../CodeGen/AMDGPU/amdgpu-cs-chain-invalid-arch.ll     |  6 ++++++
 2 files changed, 14 insertions(+), 2 deletions(-)
 create mode 100644 llvm/test/CodeGen/AMDGPU/amdgpu-cs-chain-invalid-arch.ll

diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 1d3c379f461fa..63ae083fec8e8 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -2938,10 +2938,16 @@ void Verifier::visitFunction(const Function &F) {
           "Calling convention parameter requires byval", &F);
     break;
   }
-  case CallingConv::AMDGPU_KERNEL:
-  case CallingConv::SPIR_KERNEL:
   case CallingConv::AMDGPU_CS_Chain:
   case CallingConv::AMDGPU_CS_ChainPreserve:
+  {
+    auto TT = M.getTargetTriple().str();
+    if (TT.find("gfx1200") || TT.find("gfx942"))
+      Check(false, "Chain calling convention is invalid on this target", &F);
+  }
+    [[fallthrough]];
+  case CallingConv::AMDGPU_KERNEL:
+  case CallingConv::SPIR_KERNEL:
     Check(F.getReturnType()->isVoidTy(),
           "Calling convention requires void return type", &F);
     [[fallthrough]];
diff --git a/llvm/test/CodeGen/AMDGPU/amdgpu-cs-chain-invalid-arch.ll b/llvm/test/CodeGen/AMDGPU/amdgpu-cs-chain-invalid-arch.ll
new file mode 100644
index 0000000000000..c6f8a09eaf5b6
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/amdgpu-cs-chain-invalid-arch.ll
@@ -0,0 +1,6 @@
+; RUN: not llc -mtriple=amdgcn -mcpu=gfx1200 -o - < %s 2>&1 | FileCheck %s
+
+define amdgpu_cs_chain void @test_alloca() {
+; CHECK: Chain calling convention is invalid on this target
+  ret void
+}