[SelectionDAG] Fix an incorrect DebugLoc on a COPY (#122963)

Fixes: SWDEV-502134

Author: epilk

llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp

@@ -351,8 +351,9 @@ InstrEmitter::AddRegisterOperand(MachineInstrBuilder &MIB,
         OpRC = TRI->getAllocatableClass(OpRC);
         assert(OpRC && "Constraints cannot be fulfilled for allocation");
         Register NewVReg = MRI->createVirtualRegister(OpRC);
-        BuildMI(*MBB, InsertPos, Op.getNode()->getDebugLoc(),
-                TII->get(TargetOpcode::COPY), NewVReg).addReg(VReg);
+        BuildMI(*MBB, InsertPos, MIB->getDebugLoc(),
+                TII->get(TargetOpcode::COPY), NewVReg)
+            .addReg(VReg);
         VReg = NewVReg;
       } else {
         assert(ConstrainedRC->isAllocatable() &&

llvm/test/DebugInfo/AMDGPU/debug-loc-copy.ll

@@ -0,0 +1,70 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1030 < %s | FileCheck -check-prefix=GCN %s
+
+; Verify that the debug locations in this function are correct, in particular
+; that the location for %cast doesn't appear in the block of %lab.
+
+define void @_Z12lane_pc_testj() #0 !dbg !9 {
+; GCN-LABEL: _Z12lane_pc_testj:
+; GCN:       .Lfunc_begin0:
+; GCN-NEXT:    .file 0 "/" "t.cpp"
+; GCN-NEXT:    .loc 0 3 0 ; t.cpp:3:0
+; GCN-NEXT:    .cfi_sections .debug_frame
+; GCN-NEXT:    .cfi_startproc
+; GCN-NEXT:  ; %bb.0:
+; GCN-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
+; GCN-NEXT:  ; %bb.1: ; %lab
+; GCN-NEXT:  .Ltmp0:
+; GCN-NEXT:    .loc 0 12 1 prologue_end ; t.cpp:12:1
+; GCN-NEXT:    s_mov_b64 s[4:5], src_private_base
+; GCN-NEXT:    s_mov_b32 s6, 32
+; GCN-NEXT:    s_lshr_b64 s[4:5], s[4:5], s6
+; GCN-NEXT:    s_mov_b64 s[6:7], 0
+; GCN-NEXT:    s_mov_b32 s5, -1
+; GCN-NEXT:    s_lshr_b32 s8, s32, 5
+; GCN-NEXT:    s_cmp_lg_u32 s8, s5
+; GCN-NEXT:    s_cselect_b32 s5, s4, s7
+; GCN-NEXT:    s_cselect_b32 s4, s8, s6
+; GCN-NEXT:    v_mov_b32_e32 v2, 0
+; GCN-NEXT:    .loc 0 13 1 ; t.cpp:13:1
+; GCN-NEXT:    v_mov_b32_e32 v0, s4
+; GCN-NEXT:    v_mov_b32_e32 v1, s5
+; GCN-NEXT:    flat_store_dword v[0:1], v2
+; GCN-NEXT:    v_mov_b32_e32 v2, 1
+; GCN-NEXT:    .loc 0 14 1 ; t.cpp:14:1
+; GCN-NEXT:    v_mov_b32_e32 v0, s4
+; GCN-NEXT:    v_mov_b32_e32 v1, s5
+; GCN-NEXT:    flat_store_dword v[0:1], v2
+; GCN-NEXT:    s_waitcnt lgkmcnt(0)
+; GCN-NEXT:    s_setpc_b64 s[30:31]
+; GCN-NEXT:  .Ltmp1:
+  %alloc = alloca i32, align 4, addrspace(5)
+  %cast = addrspacecast ptr addrspace(5) %alloc to ptr, !dbg !12
+  br label %lab
+
+lab:
+  store i32 0, ptr %cast, align 4, !dbg !13
+  store i32 1, ptr %cast, align 4, !dbg !14
+  ret void
+}
+
+attributes #0 = { noinline optnone }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2, !3, !4, !5, !6, !7, !8}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 20.0.0git", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "t.cpp", directory: "/")
+!2 = !{i32 1, !"amdhsa_code_object_version", i32 500}
+!3 = !{i32 1, !"amdgpu_printf_kind", !"hostcall"}
+!4 = !{i32 7, !"Dwarf Version", i32 5}
+!5 = !{i32 2, !"Debug Info Version", i32 3}
+!6 = !{i32 1, !"wchar_size", i32 4}
+!7 = !{i32 8, !"PIC Level", i32 2}
+!8 = !{i32 7, !"frame-pointer", i32 2}
+!9 = distinct !DISubprogram(name: "lane_pc_test", linkageName: "_Z12lane_pc_testj", scope: !1, file: !1, line: 1, scopeLine: 3, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, type: !10, unit: !0)
+!10 = !DISubroutineType(types: !11)
+!11 = !{}
+!12 = !DILocation(line: 12, column: 1, scope: !9)
+!13 = !DILocation(line: 13, column: 1, scope: !9)
+!14 = !DILocation(line: 14, column: 1, scope: !9)