[Mlir-commits] [mlir] [flang] [WIP] Delayed privatization. (PR #79862)

[Kareem Ergawy]

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@@ -0,0 +1,43 @@
+subroutine delayed_privatization()
+  integer :: var1
+  integer :: var2
+
+!$OMP PARALLEL FIRSTPRIVATE(var1, var2)
+  var1 = var1 + var2 + 2
+!$OMP END PARALLEL
+
+end subroutine
+
+! This is what flang emits with the PoC:
+! --------------------------------------
+!
+!func.func @_QPdelayed_privatization() {
+!  %0 = fir.alloca i32 {bindc_name = "var1", uniq_name = "_QFdelayed_privatizationEvar1"}
+!  %1 = fir.alloca i32 {bindc_name = "var2", uniq_name = "_QFdelayed_privatizationEvar2"}
+!  omp.parallel private(@var1.privatizer %0, @var2.privatizer %1 : !fir.ref<i32>, !fir.ref<i32>) {
+!    %2 = fir.load %0 : !fir.ref<i32>
+!    %3 = fir.load %1 : !fir.ref<i32>
+!    %4 = arith.addi %2, %3 : i32
+!    %c2_i32 = arith.constant 2 : i32
+!    %5 = arith.addi %4, %c2_i32 : i32
+!    fir.store %5 to %0 : !fir.ref<i32>
+!    omp.terminator
+!  }
+!  return
+!}
+!
+!"omp.private"() <{function_type = (!fir.ref<i32>) -> !fir.ref<i32>, sym_name = "var1.privatizer"}> ({
----------------
ergawy wrote:

> You can use the type to unique the privatizer. Use the getTypeAsString from FIRType.

Would that work if there are multiple parallel ops in the function that need 2 different privatizers; for example one `private(x)` and another `firstprivate(x)`? Or similarly if `x` is defined in more than one function?

I ended up using the `mlir::SymbolTable::generateSymbolName` utility. Let me know if you do not like this approach.

https://github.com/llvm/llvm-project/pull/79862