Problem met when try to schedule elemwise + argmax

[sxjscience]

@tqchen I met this problem when implementing argmax and argmin in topi. The following code will raise an error

import tvm

def argmax_comp(x, y):
    idx = tvm.make.Select((x[1] >= y[1]), x[0], y[0])
    val = tvm.make.Select((x[1] >= y[1]), x[1], y[1])
    return idx, val

def argmax_init(idx_typ, val_typ):
    return tvm.const(-1, idx_typ), tvm.min_value(val_typ)

argmax = tvm.comm_reducer(argmax_comp, argmax_init, name='argmax')

m = tvm.var('m')
n = tvm.var('n')
val = tvm.placeholder((m, n), name='val', dtype='float32')
val2 = tvm.compute((m, n), lambda i, j: tvm.exp(val[i, j]), name='val2')
k = tvm.reduce_axis((0, n), 'k')
T_idx, T_val = tvm.compute((m, ), lambda i: argmax((k.var, val2[i, k]), axis=k), name='T')

s = tvm.create_schedule(T_idx.op)
s[val2].compute_inline()

tvm.lower(s, [val, T_idx, T_val], simple_mode=True)

TVMError: [14:13:24] src/op/compute_op.cc:122: Check failed: ReduceEqual(reduce_, reduce) The Reduce inputs of ComputeOp should have the same attribute except value_index

I've printed the inner info of this line https://github.com/dmlc/tvm/blob/master/src/op/compute_op.cc#L122 and I find the only difference is the reduce_.source and reduce.source.

reduce_->source=[k, val2(i, k)]
reduce->source=[k, exp(val(i, k))]

This problem does not happen if we use tvm.sum.

[tqchen]

should be fixed by #507

[sxjscience]

@tqchen The PR has solved this problem. However, I still meet the problem when running my own code. I've printed out the value of reduce_->source and reduce->source and find that although their content are the same, the same_as returns false.

TVMError: [14:19:41] D:\HKUST\tvm\src\op\compute_op.cc:122: Check failed: ReduceEqual(reduce_, reduce) The Reduce inputs of ComputeOp should have the same attribute except value_index
reduce_->combiner=comm_reducer(result=[select((x_1 >= y_1), x_0, y_0), select((x_1 >= y_1), x_1, y_1)], lhs=[x_0, x_1], rhs=[y_0, y_1], identity_element=[-1, -340282346638528859811704183484516925440.000000f])
reduce->combiner=comm_reducer(result=[select((x_1 >= y_1), x_0, y_0), select((x_1 >= y_1), x_1, y_1)], lhs=[x_0, x_1], rhs=[y_0, y_1], identity_element=[-1, -340282346638528859811704183484516925440.000000f])
1
reduce_->source=[T.rf(k.inner.v, ax0), T.rf(k.inner.v, ax0)]
reduce->source=[T.rf(k.inner.v, ax0), T.rf(k.inner.v, ax0)]
0
reduce_->axis=[iter_var(k.inner.v, Range(min=0, extent=16))]
reduce->axis=[iter_var(k.inner.v, Range(min=0, extent=16))]
1
reduce_->condition=(uint1)1
reduce->condition=(uint1)1
1