llvm-project

1b370ef0 - [flang][OpenMP] Handle pre-detemined `lastprivate` for `simd`

[flang][OpenMP] Handle pre-detemined `lastprivate` for `simd` This PR to tries to fix `lastprivate` update issues in composite constructs. In particular, pre-determined `lastprivate` symbols are attached to the wrong leaf of the composite construct (the outermost one). When using delayed privatization (should be the default mode in the future), this results in trying to update the `lastprivate` symbol in the wrong construct (outside the `omp.loop_nest` op). For example, given the following input: ```fortran !$omp target teams distribute parallel do simd collapse(2) private(y_max) do i=x_min,x_max do j=y_min,y_max enddo enddo ``` Without the fixes introduced in this PR, the `DataSharingProcessor` tries to generate the `lastprivate` update ops in the `parallel` op since this is the op for which the DSP instance is created. The fix consists of 2 main parts: 1. Instead of creating a single DSP instance, one instance is created for the leaf constructs that might need privatization (whether for explicit, implicit, or pre-determined symbols). 2. When generating the `lastprivate` comparison ops, we don't durectly use the SSA values of the UBs and steps. Instead, we regenerated these SSA values from the original loop bounds' expressions. We have to do this to avoid using `host_eval` values in the `lastprivate` comparison logic which is illegal.