[Mlir-commits] [mlir] [mlir][arith] add wide integer emulation support for subi (PR #133248)

[Jakub Kuderski]

================
@@ -0,0 +1,81 @@
+// Ops in this function will be emulated using i16 types.
+
+// RUN: mlir-opt %s --convert-scf-to-cf --convert-cf-to-llvm --convert-vector-to-llvm \
+// RUN:             --convert-func-to-llvm --convert-arith-to-llvm | \
+// RUN:   mlir-runner -e entry -entry-point-result=void \
+// RUN:                   --shared-libs=%mlir_c_runner_utils | \
+// RUN:   FileCheck %s --match-full-lines
+
+// RUN: mlir-opt %s --test-arith-emulate-wide-int="widest-int-supported=16" \
+// RUN:             --convert-scf-to-cf --convert-cf-to-llvm --convert-vector-to-llvm \
+// RUN:             --convert-func-to-llvm --convert-arith-to-llvm | \
+// RUN:   mlir-runner -e entry -entry-point-result=void \
+// RUN:                   --shared-libs=%mlir_c_runner_utils | \
+// RUN:   FileCheck %s --match-full-lines
+
+func.func @emulate_subi(%arg: i32, %arg0: i32) -> i32 {
+  %res = arith.subi %arg, %arg0 : i32
+  return %res : i32
+}
+
+func.func @check_subi(%arg : i32, %arg0 : i32) -> () {
+  %res = func.call @emulate_subi(%arg, %arg0) : (i32, i32) -> (i32)
+  vector.print %res : i32
+  return
+}
+
+func.func @entry() {
+  %lhs1 = arith.constant 1 : i32
+  %rhs1 = arith.constant 2 : i32
+
+  // CHECK:       -1
+  func.call @check_subi(%lhs1, %rhs1) : (i32, i32) -> ()
+  // CHECK-NEXT:  1
+  func.call @check_subi(%rhs1, %lhs1) : (i32, i32) -> ()
+  
+  %lhs2 = arith.constant 1 : i32
+  %rhs2 = arith.constant -2 : i32
+
+  // CHECK-NEXT:  3
+  func.call @check_subi(%lhs2, %rhs2) : (i32, i32) -> ()
+  // CHECK-NEXT:  -3
+  func.call @check_subi(%rhs2, %lhs2) : (i32, i32) -> ()
+  
+  %lhs3 = arith.constant -1 : i32
+  %rhs3 = arith.constant -2 : i32
+
+  // CHECK-NEXT:  1
+  func.call @check_subi(%lhs3, %rhs3) : (i32, i32) -> ()
+  // CHECK-NEXT:  -1
+  func.call @check_subi(%rhs3, %lhs3) : (i32, i32) -> ()
+  
+  // Overflow from the upper/lower part
+  %lhs4 = arith.constant 131074 : i32
+  %rhs4 = arith.constant 3 : i32
+
+  // CHECK-NEXT:  131071
+  func.call @check_subi(%lhs4, %rhs4) : (i32, i32) -> ()
+  // CHECK-NEXT:  -131071
+  func.call @check_subi(%rhs4, %lhs4) : (i32, i32) -> ()
+
+  // Overflow in both parts
----------------
kuhar wrote:

```suggestion
  // Overflow in both parts.
```

https://github.com/llvm/llvm-project/pull/133248