[llvm] [CodeGen] Parse nusw flag (PR #138856)

[Pierre van Houtryve via llvm-commits]

https://github.com/Pierre-vh created https://github.com/llvm/llvm-project/pull/138856

Fixes #127781

>From dd83ecb140052cae9862ef4d2590c04a0b0f18ff Mon Sep 17 00:00:00 2001
From: pvanhout <pierre.vanhoutryve at amd.com>
Date: Wed, 7 May 2025 14:31:10 +0200
Subject: [PATCH] [CodeGen] Parse nusw flag

Fixes #127781
---
 llvm/lib/CodeGen/MIRParser/MIParser.cpp       |  3 +++
 .../AMDGPU/GlobalISel/ptradd-flags.mir        | 23 +++++++++++++++++++
 2 files changed, 26 insertions(+)
 create mode 100644 llvm/test/CodeGen/AMDGPU/GlobalISel/ptradd-flags.mir

diff --git a/llvm/lib/CodeGen/MIRParser/MIParser.cpp b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
index 5c8e32d11cfb0..858cdb6599c62 100644
--- a/llvm/lib/CodeGen/MIRParser/MIParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIParser.cpp
@@ -1476,6 +1476,7 @@ bool MIParser::parseInstruction(unsigned &OpCode, unsigned &Flags) {
          Token.is(MIToken::kw_unpredictable) ||
          Token.is(MIToken::kw_nneg) ||
          Token.is(MIToken::kw_disjoint) ||
+         Token.is(MIToken::kw_nusw) ||
          Token.is(MIToken::kw_samesign)) {
     // clang-format on
     // Mine frame and fast math flags
@@ -1513,6 +1514,8 @@ bool MIParser::parseInstruction(unsigned &OpCode, unsigned &Flags) {
       Flags |= MachineInstr::NonNeg;
     if (Token.is(MIToken::kw_disjoint))
       Flags |= MachineInstr::Disjoint;
+    if (Token.is(MIToken::kw_nusw))
+      Flags |= MachineInstr::NoUSWrap;
     if (Token.is(MIToken::kw_samesign))
       Flags |= MachineInstr::SameSign;
 
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/ptradd-flags.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/ptradd-flags.mir
new file mode 100644
index 0000000000000..2da0eb7be0677
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/ptradd-flags.mir
@@ -0,0 +1,23 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
+# RUN: llc -mtriple=amdgcn -mcpu=gfx900 -run-pass=none -verify-machineinstrs %s -o - | FileCheck %s
+
+---
+name:  nusw_ptr_add
+legalized:       true
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1, $vgpr2_vgpr3
+
+    ; CHECK-LABEL: name: nusw_ptr_add
+    ; CHECK: liveins: $vgpr0_vgpr1, $vgpr2_vgpr3
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %ptr:_(p0) = COPY $vgpr0_vgpr1
+    ; CHECK-NEXT: %off:_(s64) = COPY $vgpr2_vgpr3
+    ; CHECK-NEXT: %ret:_(p0) = nuw nusw G_PTR_ADD %ptr, %off(s64)
+    ; CHECK-NEXT: $vgpr0_vgpr1 = COPY %ret(p0)
+    %ptr:_(p0) = COPY $vgpr0_vgpr1
+    %off:_(s64) = COPY $vgpr2_vgpr3
+    %ret:_(p0) = nuw nusw G_PTR_ADD %ptr, %off
+    $vgpr0_vgpr1 = COPY %ret
+...