[llvm] check t16 in dpp inst creator (PR #128918)

[Brox Chen via llvm-commits]

https://github.com/broxigarchen created https://github.com/llvm/llvm-project/pull/128918

None

>From 3ad31534132fcf4a967ba094145a5e87327c0fc6 Mon Sep 17 00:00:00 2001
From: guochen2 <guochen2 at amd.com>
Date: Wed, 26 Feb 2025 12:08:03 -0500
Subject: [PATCH] check t16 in dpp inst creator

---
 llvm/lib/Target/AMDGPU/GCNDPPCombine.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/llvm/lib/Target/AMDGPU/GCNDPPCombine.cpp b/llvm/lib/Target/AMDGPU/GCNDPPCombine.cpp
index b22babb4a00d8..9a7c1f5d7885b 100644
--- a/llvm/lib/Target/AMDGPU/GCNDPPCombine.cpp
+++ b/llvm/lib/Target/AMDGPU/GCNDPPCombine.cpp
@@ -215,6 +215,11 @@ MachineInstr *GCNDPPCombine::createDPPInst(MachineInstr &OrigMI,
 
   bool HasVOP3DPP = ST->hasVOP3DPP();
   auto OrigOp = OrigMI.getOpcode();
+  if(AMDGPU::isTrue16Inst(OrigOp)) {
+    LLVM_DEBUG(
+        dbgs() << "  failed: Did not expect any 16-bit uses of dpp values\n");
+    return nullptr;
+  }
   auto DPPOp = getDPPOp(OrigOp, IsShrinkable);
   if (DPPOp == -1) {
     LLVM_DEBUG(dbgs() << "  failed: no DPP opcode\n");