Hotfixes psy2dawn

[mroethlin]

Technical Description

This PR contains some hot fixes for the Psy2Dawn Project. This should probably be 3 PRs but since this project is EOL I deemed it acceptable to have a summary PR for this

Resolves / Enhances

• Add sign function to the toolchain
• Make the checkOffset function in generated code static for easier linking of multiple stencils into one library
• Fix the code generation for iteration spaces on the cuda backend to use the physical address when checking against the offset instead of the index in the block. Note that this is only tested for the situation where GRIDTOOLS_DAWN_HALO_EXTENT=0
• Fix an issue where, in the cuda backend, checks would be emitted for all iteration spaces in the stencil, not only the iteration spaces associated with a given stage
• Fix an issue if a MS is generated that only uses a temp field. In that case, no strides would be generated, effectively only iterating over one column of the temp field.

Example

A simple iteration space

    iteration_space(i_start + 1, i_end-1, j_start + 1, j_end - 1, k_start + 1, k_end - 1) {
      out = 1;
    }

would lead to false positive testing against the iteration space along the j domain in a test case found during the psy2dawn deliverable.

In the cuda backend, a sequence like

    iteration_space(i_start + 1, i_end-1, j_start + 1, j_end - 1, k_start + 1, k_end - 1) {
      out = 1;
    }

    iteration_space(j_start + 1, j_end - 1, k_start + 1, k_end - 1) {
      out = 2;
    }

would be spuriously compiled to the equivalent of

    iteration_space(i_start + 1, i_end-1, j_start + 1, j_end - 1, k_start + 1, k_end - 1) {
      out = 1;
    }

    iteration_space(j_start + 1, j_end - 1, j_start + 1, j_end - 1, k_start + 1, k_end - 1) {
      out = 2;
    }

Testing

• Three new tests were added to the code generation tests of gtclang
• A test had to be adapted to the new codegen

Dependencies

This PR is independent.

[mroethlin]

launch jenkins

[mroethlin]

launch jenkins

[mroethlin]

launch jenkins

[mroethlin]

launch jenkins

[mroethlin]

launch jenkins