min:   min,
				max:   max,
				entry: b.Succs[0].b,
				flags: flags,
			})
			b.Logf("found induction variable %v (inc = %v, min = %v, max = %v)\n", ind, inc, min, max)
		}

		// TODO: other unrolling idioms
		// for i := 0; i < KNN - KNN % k ; i += k
		// for i := 0; i < KNN&^(k-1) ; i += k // k a power of 2
		// for i := 0; i < KNN&(-k) ; i += k // k a power of 2
	}

	return iv
}

					continue
				}
				return nil
			}
		}
	}
	// Creates a slightly optimized copy of the original Prog
	// that cleans up some Prog idioms that block valid onepass programs
	p = onePassCopy(prog)

	// checkAmbiguity on InstAlts, build onepass Prog if possible
	p = makeOnePass(p)

	if p != nil {
		cleanupOnePass(p, prog)
	}
	return p

}

func main() {
	go f()
	g()
}
</pre>

<p>
it can happen that <code>g</code> prints <code>2</code> and then <code>0</code>.
</p>

<p>
This fact invalidates a few common idioms.
</p>

<p>
Double-checked locking is an attempt to avoid the overhead of synchronization.
For example, the <code>twoprint</code> program might be
incorrectly written as:
</p>

<pre>
var a string

	InParallel    bool // parallel backend phase in effect
	UseBASEntries bool // use Base Address Selection Entries in location lists and PC ranges
	IsAsm         bool // is the source assembly language, which may contain surprising idioms (e.g., call tables)
	Std           bool // is standard library package

	// state for writing objects
	Text []*LSym
	Data []*LSym

	// Constant symbols (e.g. $i64.*) are data symbols created late

  constexpr int64_t dims[] = {100, 100};
  constexpr int num_elements = dims[0] * dims[1];
  float data[num_elements];
  for (int i = 0; i < num_elements; ++i) {
    data[i] = 1.0f;
  }
  TF_Status* status = TF_NewStatus();
  TF_Tensor* t = TFE_AllocateHostTensor(ctx, TF_FLOAT, &dims[0],
                                        sizeof(dims) / sizeof(int64_t), status);

	c := testConfig(t)
	fun := c.Fun("entry",
		Bloc("entry",
			Valu("mem", OpInitMem, types.TypeMem, 0, nil),
			Exit("mem")))

	doms := map[string]string{}

	CheckFunc(fun.f)
	verifyDominators(t, fun, dominators, doms)
	verifyDominators(t, fun, dominatorsSimple, doms)

}

func TestDominatorsSimple(t *testing.T) {
	c := testConfig(t)
	fun := c.Fun("entry",
		Bloc("entry",

    - mikedanese
  sig-auth-authorizers-reviewers:
    - deads2k
    - dims
    - enj
    - liggitt
    - mikedanese
    - ncdc
    - smarterclayton
    - sttts
    - thockin
    - wojtek-t
  sig-auth-certificates-approvers:
    - liggitt
    - mikedanese
    - smarterclayton
  sig-auth-certificates-reviewers:
    - deads2k
    - dims
    - enj
    - liggitt
    - mikedanese

  static char empty;
  int64_t nelems = 1;
  std::vector<int64_t> dims;
  auto shape_dims = shape.dims();
  dims.reserve(shape_dims);
  for (int i = 0; i < shape_dims; ++i) {
    dims.push_back(shape.dim_size(i));
    nelems *= shape.dim_size(i);
  }
  CHECK_EQ(nelems, 0);
  return TF_NewTensor(
      dtype, reinterpret_cast<const int64_t*>(dims.data()), shape.dims(),

  %1 = stablehlo.transpose %arg0, dims = [0, 3, 1, 2] : (tensor<1x3x3x4xf32>) -> tensor<1x4x3x3xf32>
  %2 = stablehlo.add %1, %0 : tensor<1x4x3x3xf32>
  return %2 : tensor<1x4x3x3xf32>
}
// CHECK-SAME: (%[[ARG_0:.+]]: tensor<1x3x3x4xf32>) -> tensor<1x4x3x3xf32>
// CHECK-DAG: %[[CONST_0:.+]] = stablehlo.constant

// CHECK-DAG: %[[BIAS_CONST:.+]] = stablehlo.constant {{.*}} : tensor<4xf32>
// CHECK-DAG: %[[BROADCAST_IN_DIM:.+]] = stablehlo.broadcast_in_dim %[[BIAS_CONST]], dims = [1] : (tensor<4xf32>) -> tensor<1x4x5x5xf32>
// CHECK-DAG: %[[TRANSPOSE_0:.+]] = stablehlo.transpose %[[ARG]], dims = [0, 2, 3, 1] : (tensor<1x2x5x5xf32>) -> tensor<1x5x5x2xf32>