[InstCombine][DebugInfo] Update debug info after inverting a boolean instruction

Author: dtcxzyw

llvm/lib/Transforms/InstCombine/InstructionCombining.cpp

@@ -1187,6 +1187,13 @@ void InstCombinerImpl::freelyInvertAllUsersOf(Value *I, Value *IgnoredUser) {
                        "canFreelyInvertAllUsersOf() ?");
     }
   }
+
+  // Adapt all dbg users
+  if (auto *Inst = dyn_cast<Instruction>(I); Inst && Inst->isUsedByMetadata()) {
+    auto *Not = Builder.CreateNot(I);
+    auto *NotInst = dyn_cast<Instruction>(I);
+    replaceAllDbgUsesWith(*Inst, *Not, NotInst ? *NotInst : *Inst, DT);
+  }
 }
 
 /// Given a 'sub' instruction, return the RHS of the instruction if the LHS is a

llvm/test/DebugInfo/salvage-invert-bool.ll

@@ -6,7 +6,7 @@ define i32 @test_invert_bool(i32 %call, i32 %a) {
 ; CHECK-SAME: i32 [[CALL:%.*]], i32 [[A:%.*]]) {
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[TOBOOL_NOT:%.*]] = icmp eq i32 [[CALL]], 0
-; CHECK-NEXT:    call void @llvm.dbg.value(metadata i1 [[TOBOOL_NOT]], metadata [[META3:![0-9]+]], metadata !DIExpression(DW_OP_LLVM_convert, 1, DW_ATE_unsigned, DW_OP_LLVM_convert, 32, DW_ATE_unsigned, DW_OP_stack_value)), !dbg [[DBG8:![0-9]+]]
+; CHECK-NEXT:    call void @llvm.dbg.value(metadata i1 [[TOBOOL_NOT]], metadata [[META3:![0-9]+]], metadata !DIExpression(DW_OP_constu, 18446744073709551615, DW_OP_xor, DW_OP_LLVM_convert, 1, DW_ATE_unsigned, DW_OP_LLVM_convert, 32, DW_ATE_unsigned, DW_OP_stack_value)), !dbg [[DBG8:![0-9]+]]
 ; CHECK-NEXT:    [[TMP0:%.*]] = and i32 [[A]], 1
 ; CHECK-NEXT:    [[AND:%.*]] = select i1 [[TOBOOL_NOT]], i32 0, i32 [[TMP0]]
 ; CHECK-NEXT:    ret i32 [[AND]]