This patch is to add cray pointer (aka integer pointer) support to flang. Syntax and semantic checking were already available in flang.
Cray pointers reference (https://gcc.gnu.org/onlinedocs/gfortran/Cray-pointers.html)
In order to implement the feature we create the following sequence for a simple scalar load and store:
integer pte, i pointer(ptr, pte) i = pte
%1 = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFEi"}
%2 = fir.alloca i32 {bindc_name = "pte", uniq_name = "_QFEpte"}
%3 = fir.alloca i64 {bindc_name = "ptr", uniq_name = "_QFEptr"}
...
%7 = fir.embox %3 : (!fir.ref<i64>) -> !fir.box<i64>
%8 = fir.box_addr %7 : (!fir.box<i64>) -> !fir.ref<i64>
%9 = fir.convert %8 : (!fir.ref<i64>) -> !fir.ref<!fir.ptr<i32>>
%10 = fir.load %9 : !fir.ref<!fir.ptr<i32>>
%11 = fir.load %10 : !fir.ptr<i32>
fir.store %11 to %1 : !fir.ref<i32>integer pte, i pointer(ptr, pte) pte = i
%1 = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFEi"}
%2 = fir.alloca i32 {bindc_name = "pte", uniq_name = "_QFEpte"}
%3 = fir.alloca i64 {bindc_name = "ptr", uniq_name = "_QFEptr"}
%7 = fir.load %1 : !fir.ref<i32>
%8 = fir.embox %3 : (!fir.ref<i64>) -> !fir.box<i64>
%9 = fir.box_addr %8 : (!fir.box<i64>) -> !fir.ref<i64>
%10 = fir.convert %9 : (!fir.ref<i64>) -> !fir.ref<!fir.ptr<i32>>
%11 = fir.load %10 : !fir.ref<!fir.ptr<i32>>
fir.store %7 to %11 : !fir.ptr<i32>The sequence is very similar for array element cases with the addition of fir.coordinate_of for the specific element.
The whole array case is slightly different but uses the same sequence before the fir.array_load and fir.array_merge_store.
Spell auto.