[llvm] [LLVM][NVPTX] Add support for brkpt instruction (PR #104470)

[Pradeep Kumar via llvm-commits]

https://github.com/schwarzschild-radius created https://github.com/llvm/llvm-project/pull/104470

This commit adds NVPTX codegen support for brkpt instruction (https://docs.nvidia.com/cuda/parallel-thread-execution/#miscellaneous-instructions-brkpt) with test under CodeGen/NVPTX/brkpt.ll

>From 0e47ebf3610c3f9b13931476f6a2ab96bed6825d Mon Sep 17 00:00:00 2001
From: pradeepku <pradeepku at nvidia.com>
Date: Wed, 14 Aug 2024 14:15:28 +0000
Subject: [PATCH] [LLVM][NVPTX] Add support for brkpt instruction

This commit adds NVPTX codegen support for brkpt instruction
(https://docs.nvidia.com/cuda/parallel-thread-execution/#miscellaneous-instructions-brkpt) with test
under CodeGen/NVPTX/brkpt.ll
---
 llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp | 2 ++
 llvm/lib/Target/NVPTX/NVPTXInstrInfo.td     | 2 ++
 llvm/test/CodeGen/NVPTX/brkpt.ll            | 8 ++++++++
 3 files changed, 12 insertions(+)
 create mode 100644 llvm/test/CodeGen/NVPTX/brkpt.ll

diff --git a/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp b/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
index 43a3fbf4d1306a..577141299b9496 100644
--- a/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
+++ b/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
@@ -648,6 +648,8 @@ NVPTXTargetLowering::NVPTXTargetLowering(const NVPTXTargetMachine &TM,
 
   // TRAP can be lowered to PTX trap
   setOperationAction(ISD::TRAP, MVT::Other, Legal);
+  // DEBUGTRAP can be lowered to PTX brkpt
+  setOperationAction(ISD::DEBUGTRAP, MVT::Other, Legal);
 
   // Register custom handling for vector loads/stores
   for (MVT VT : MVT::fixedlen_vector_valuetypes()) {
diff --git a/llvm/lib/Target/NVPTX/NVPTXInstrInfo.td b/llvm/lib/Target/NVPTX/NVPTXInstrInfo.td
index d75dc8781f7802..e56e4c7055bc3e 100644
--- a/llvm/lib/Target/NVPTX/NVPTXInstrInfo.td
+++ b/llvm/lib/Target/NVPTX/NVPTXInstrInfo.td
@@ -3844,6 +3844,8 @@ def Callseq_End :
 // Emit an `exit` as well to convey to ptxas that `trap` exits the CFG.
 // This won't be necessary in a future version of ptxas.
 def trapinst : NVPTXInst<(outs), (ins), "trap; exit;", [(trap)]>;
+// brkpt instruction
+def debugtrapinst : NVPTXInst<(outs), (ins), "brkpt;", [(debugtrap)]>;
 
 // Call prototype wrapper
 def SDTCallPrototype : SDTypeProfile<0, 1, [SDTCisInt<0>]>;
diff --git a/llvm/test/CodeGen/NVPTX/brkpt.ll b/llvm/test/CodeGen/NVPTX/brkpt.ll
new file mode 100644
index 00000000000000..beb2ff6aed6c9c
--- /dev/null
+++ b/llvm/test/CodeGen/NVPTX/brkpt.ll
@@ -0,0 +1,8 @@
+; RUN: llc -o - -march=nvptx64 %s | FileCheck %s
+
+; CHECK-LABEL: .func breakpoint
+define void @breakpoint() {
+  ; CHECK: brkpt;
+  call void @llvm.debugtrap()
+  ret void
+}