[flang-commits] [flang] [Flang][OpenMP] Use simdloop operation only for omp simd pragma (PR #79559)
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Fri Jan 26 00:54:18 PST 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-flang-fir-hlfir
@llvm/pr-subscribers-flang-openmp
Author: Dominik Adamski (DominikAdamski)
<details>
<summary>Changes</summary>
OpenMP standard differentiates between omp simd (2.9.3.1) and omp do/for simd (2.9.3.2 for OpenMP 5.0 standard) pragmas. The first one describes the loop which needs to be vectorized. The second pragma describes the loop which needs to be workshared between existing threads. Each thread can use SIMD instructions to execute its chunk of the loop.
That's why we need to model
```
!$omp simd
do-loop
```
as `omp.simdloop` operation and add compiler hints for vectorization.
The worksharing loop:
!$omp do simd
do-loop
should be represented as worksharing loop (`omp.wsloop`).
Currently Flang denotes both type of OpenMP pragmas by `omp.simdloop` operation. In consequence we cannot differentiate between:
```
!$omp parallel simd
do-loop
```
and
```
!$omp parallel do simd
do-loop
```
The second loop should be workshared between multiple threads. The first one describes the loop which needs to be redundantly executed by multiple threads. Current Flang implementation does not perform worksharing for `!$omp do simd` pragma and generates valid code only for first case.
@<!-- -->skatrak will propose detailed MLIR representation of `!$omp do simd` pragma
---
Full diff: https://github.com/llvm/llvm-project/pull/79559.diff
9 Files Affected:
- (modified) flang/lib/Lower/OpenMP.cpp (+47-3)
- (modified) flang/test/Lower/OpenMP/FIR/if-clause.f90 (+13-21)
- (modified) flang/test/Lower/OpenMP/FIR/loop-combined.f90 (+3-3)
- (added) flang/test/Lower/OpenMP/Todo/omp-do-simd-aligned.f90 (+16)
- (added) flang/test/Lower/OpenMP/Todo/omp-do-simd-linear.f90 (+14)
- (added) flang/test/Lower/OpenMP/Todo/omp-do-simd-safelen.f90 (+14)
- (added) flang/test/Lower/OpenMP/Todo/omp-do-simd-simdlen.f90 (+14)
- (modified) flang/test/Lower/OpenMP/if-clause.f90 (+13-21)
- (modified) flang/test/Lower/OpenMP/loop-combined.f90 (+3-3)
``````````diff
diff --git a/flang/lib/Lower/OpenMP.cpp b/flang/lib/Lower/OpenMP.cpp
index d2215f4d1bf1ce..0888b25f1c59d5 100644
--- a/flang/lib/Lower/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP.cpp
@@ -3311,6 +3311,43 @@ static void createWsLoop(Fortran::lower::AbstractConverter &converter,
/*outer=*/false, &dsp);
}
+static void createSimdWsLoop(
+ Fortran::lower::AbstractConverter &converter,
+ Fortran::lower::pft::Evaluation &eval, llvm::omp::Directive ompDirective,
+ const Fortran::parser::OmpClauseList &beginClauseList,
+ const Fortran::parser::OmpClauseList *endClauseList, mlir::Location loc) {
+ ClauseProcessor cp(converter, beginClauseList);
+ cp.processTODO<
+ Fortran::parser::OmpClause::Aligned, Fortran::parser::OmpClause::Allocate,
+ Fortran::parser::OmpClause::Linear, Fortran::parser::OmpClause::Safelen,
+ Fortran::parser::OmpClause::Simdlen, Fortran::parser::OmpClause::Order>(
+ loc, ompDirective);
+ // TODO: Add support for vectorization - add vectorization hints inside loop
+ // body.
+ // OpenMP standard does not specify the length of vector instructions.
+ // Currently we safely assume that for !$omp do simd pragma the SIMD length
+ // is equal to 1 (i.e. we generate standard workshare loop).
+ // When support for vectorization is enabled, then we need to add handling of
+ // if clause. Currently if clause can be skipped because we always assume
+ // SIMD length = 1.
+ createWsLoop(converter, eval, ompDirective, beginClauseList, endClauseList,
+ loc);
+}
+
+static bool isWorkshareSimdConstruct(llvm::omp::Directive ompDirective) {
+ switch (ompDirective) {
+ default:
+ return false;
+ case llvm::omp::OMPD_distribute_parallel_do_simd:
+ case llvm::omp::OMPD_do_simd:
+ case llvm::omp::OMPD_parallel_do_simd:
+ case llvm::omp::OMPD_target_parallel_do_simd:
+ case llvm::omp::OMPD_target_teams_distribute_parallel_do_simd:
+ case llvm::omp::OMPD_teams_distribute_parallel_do_simd:
+ return true;
+ }
+}
+
static void genOMP(Fortran::lower::AbstractConverter &converter,
Fortran::lower::SymMap &symTable,
Fortran::semantics::SemanticsContext &semanticsContext,
@@ -3377,10 +3414,17 @@ static void genOMP(Fortran::lower::AbstractConverter &converter,
")");
}
- // 2.9.3.1 SIMD construct
if (llvm::omp::allSimdSet.test(ompDirective)) {
- createSimdLoop(converter, eval, ompDirective, loopOpClauseList,
- currentLocation);
+ if (isWorkshareSimdConstruct(ompDirective)) {
+ // 2.9.3.2 Workshare SIMD construct
+ createSimdWsLoop(converter, eval, ompDirective, loopOpClauseList,
+ endClauseList, currentLocation);
+
+ } else {
+ // 2.9.3.1 SIMD construct
+ createSimdLoop(converter, eval, ompDirective, loopOpClauseList,
+ currentLocation);
+ }
} else {
createWsLoop(converter, eval, ompDirective, loopOpClauseList, endClauseList,
currentLocation);
diff --git a/flang/test/Lower/OpenMP/FIR/if-clause.f90 b/flang/test/Lower/OpenMP/FIR/if-clause.f90
index ef98a00f10dbd2..a1235be8e61ea2 100644
--- a/flang/test/Lower/OpenMP/FIR/if-clause.f90
+++ b/flang/test/Lower/OpenMP/FIR/if-clause.f90
@@ -28,7 +28,7 @@ program main
! ----------------------------------------------------------------------------
! DO SIMD
! ----------------------------------------------------------------------------
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
!$omp do simd
@@ -36,15 +36,13 @@ program main
end do
!$omp end do simd
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp do simd if(.true.)
do i = 1, 10
end do
!$omp end do simd
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp do simd if(simd: .true.)
do i = 1, 10
end do
@@ -103,7 +101,7 @@ program main
! CHECK: omp.parallel
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
!$omp parallel do simd
@@ -113,8 +111,7 @@ program main
! CHECK: omp.parallel
! CHECK-SAME: if({{.*}})
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp parallel do simd if(.true.)
do i = 1, 10
end do
@@ -122,8 +119,7 @@ program main
! CHECK: omp.parallel
! CHECK-SAME: if({{.*}})
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp parallel do simd if(parallel: .true.) if(simd: .false.)
do i = 1, 10
end do
@@ -131,7 +127,7 @@ program main
! CHECK: omp.parallel
! CHECK-SAME: if({{.*}})
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
!$omp parallel do simd if(parallel: .true.)
@@ -142,8 +138,7 @@ program main
! CHECK: omp.parallel
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp parallel do simd if(simd: .true.)
do i = 1, 10
end do
@@ -306,7 +301,7 @@ program main
! CHECK: omp.parallel
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
!$omp target parallel do simd
@@ -318,8 +313,7 @@ program main
! CHECK-SAME: if({{.*}})
! CHECK: omp.parallel
! CHECK-SAME: if({{.*}})
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp target parallel do simd if(.true.)
do i = 1, 10
end do
@@ -329,8 +323,7 @@ program main
! CHECK-SAME: if({{.*}})
! CHECK: omp.parallel
! CHECK-SAME: if({{.*}})
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp target parallel do simd if(target: .true.) if(parallel: .false.) &
!$omp& if(simd: .true.)
do i = 1, 10
@@ -342,7 +335,7 @@ program main
! CHECK: omp.parallel
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
!$omp target parallel do simd if(target: .true.)
@@ -355,8 +348,7 @@ program main
! CHECK-SAME: {
! CHECK: omp.parallel
! CHECK-SAME: if({{.*}})
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp target parallel do simd if(parallel: .true.) if(simd: .false.)
do i = 1, 10
end do
diff --git a/flang/test/Lower/OpenMP/FIR/loop-combined.f90 b/flang/test/Lower/OpenMP/FIR/loop-combined.f90
index 117f7d625270ec..a6cec1beb49c86 100644
--- a/flang/test/Lower/OpenMP/FIR/loop-combined.f90
+++ b/flang/test/Lower/OpenMP/FIR/loop-combined.f90
@@ -23,7 +23,7 @@ program main
! ----------------------------------------------------------------------------
! DO SIMD
! ----------------------------------------------------------------------------
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
!$omp do simd
do i = 1, 10
end do
@@ -33,7 +33,7 @@ program main
! PARALLEL DO SIMD
! ----------------------------------------------------------------------------
! CHECK: omp.parallel
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
!$omp parallel do simd
do i = 1, 10
end do
@@ -54,7 +54,7 @@ program main
! ----------------------------------------------------------------------------
! CHECK: omp.target
! CHECK: omp.parallel
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
!$omp target parallel do simd
do i = 1, 10
end do
diff --git a/flang/test/Lower/OpenMP/Todo/omp-do-simd-aligned.f90 b/flang/test/Lower/OpenMP/Todo/omp-do-simd-aligned.f90
new file mode 100644
index 00000000000000..b62c54182442ac
--- /dev/null
+++ b/flang/test/Lower/OpenMP/Todo/omp-do-simd-aligned.f90
@@ -0,0 +1,16 @@
+! This test checks lowering of OpenMP do simd aligned() pragma
+
+! RUN: %not_todo_cmd bbc -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s
+! RUN: %not_todo_cmd %flang_fc1 -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s
+subroutine testDoSimdAligned(int_array)
+ use iso_c_binding
+ type(c_ptr) :: int_array
+!CHECK: not yet implemented: Unhandled clause ALIGNED in DO SIMD construct
+!$omp do simd aligned(int_array)
+ do index_ = 1, 10
+ call c_test_call(int_array)
+ end do
+!$omp end do simd
+
+end subroutine testDoSimdAligned
+
diff --git a/flang/test/Lower/OpenMP/Todo/omp-do-simd-linear.f90 b/flang/test/Lower/OpenMP/Todo/omp-do-simd-linear.f90
new file mode 100644
index 00000000000000..a9e0446ec8c34e
--- /dev/null
+++ b/flang/test/Lower/OpenMP/Todo/omp-do-simd-linear.f90
@@ -0,0 +1,14 @@
+! This test checks lowering of OpenMP do simd linear() pragma
+
+! RUN: %not_todo_cmd bbc -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s
+! RUN: %not_todo_cmd %flang_fc1 -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s
+subroutine testDoSimdLinear(int_array)
+ integer :: int_array(*)
+!CHECK: not yet implemented: Unhandled clause LINEAR in DO SIMD construct
+!$omp do simd linear(int_array)
+ do index_ = 1, 10
+ end do
+!$omp end do simd
+
+end subroutine testDoSimdLinear
+
diff --git a/flang/test/Lower/OpenMP/Todo/omp-do-simd-safelen.f90 b/flang/test/Lower/OpenMP/Todo/omp-do-simd-safelen.f90
new file mode 100644
index 00000000000000..054eb52ea170ac
--- /dev/null
+++ b/flang/test/Lower/OpenMP/Todo/omp-do-simd-safelen.f90
@@ -0,0 +1,14 @@
+! This test checks lowering of OpenMP do simd safelen() pragma
+
+! RUN: %not_todo_cmd bbc -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s
+! RUN: %not_todo_cmd %flang_fc1 -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s
+subroutine testDoSimdSafelen(int_array)
+ integer :: int_array(*)
+!CHECK: not yet implemented: Unhandled clause SAFELEN in DO SIMD construct
+!$omp do simd safelen(4)
+ do index_ = 1, 10
+ end do
+!$omp end do simd
+
+end subroutine testDoSimdSafelen
+
diff --git a/flang/test/Lower/OpenMP/Todo/omp-do-simd-simdlen.f90 b/flang/test/Lower/OpenMP/Todo/omp-do-simd-simdlen.f90
new file mode 100644
index 00000000000000..bd00b6f336c931
--- /dev/null
+++ b/flang/test/Lower/OpenMP/Todo/omp-do-simd-simdlen.f90
@@ -0,0 +1,14 @@
+! This test checks lowering of OpenMP do simd simdlen() pragma
+
+! RUN: %not_todo_cmd bbc -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s
+! RUN: %not_todo_cmd %flang_fc1 -emit-fir -fopenmp -o - %s 2>&1 | FileCheck %s
+subroutine testDoSimdSimdlen(int_array)
+ integer :: int_array(*)
+!CHECK: not yet implemented: Unhandled clause SIMDLEN in DO SIMD construct
+!$omp do simd simdlen(4)
+ do index_ = 1, 10
+ end do
+!$omp end do simd
+
+end subroutine testDoSimdSimdlen
+
diff --git a/flang/test/Lower/OpenMP/if-clause.f90 b/flang/test/Lower/OpenMP/if-clause.f90
index 032009add31535..f982bf67b07225 100644
--- a/flang/test/Lower/OpenMP/if-clause.f90
+++ b/flang/test/Lower/OpenMP/if-clause.f90
@@ -28,7 +28,7 @@ program main
! ----------------------------------------------------------------------------
! DO SIMD
! ----------------------------------------------------------------------------
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
!$omp do simd
@@ -36,15 +36,13 @@ program main
end do
!$omp end do simd
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp do simd if(.true.)
do i = 1, 10
end do
!$omp end do simd
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp do simd if(simd: .true.)
do i = 1, 10
end do
@@ -103,7 +101,7 @@ program main
! CHECK: omp.parallel
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
!$omp parallel do simd
@@ -113,8 +111,7 @@ program main
! CHECK: omp.parallel
! CHECK-SAME: if({{.*}})
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp parallel do simd if(.true.)
do i = 1, 10
end do
@@ -122,8 +119,7 @@ program main
! CHECK: omp.parallel
! CHECK-SAME: if({{.*}})
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp parallel do simd if(parallel: .true.) if(simd: .false.)
do i = 1, 10
end do
@@ -131,7 +127,7 @@ program main
! CHECK: omp.parallel
! CHECK-SAME: if({{.*}})
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
!$omp parallel do simd if(parallel: .true.)
@@ -142,8 +138,7 @@ program main
! CHECK: omp.parallel
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp parallel do simd if(simd: .true.)
do i = 1, 10
end do
@@ -306,7 +301,7 @@ program main
! CHECK: omp.parallel
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
!$omp target parallel do simd
@@ -318,8 +313,7 @@ program main
! CHECK-SAME: if({{.*}})
! CHECK: omp.parallel
! CHECK-SAME: if({{.*}})
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp target parallel do simd if(.true.)
do i = 1, 10
end do
@@ -329,8 +323,7 @@ program main
! CHECK-SAME: if({{.*}})
! CHECK: omp.parallel
! CHECK-SAME: if({{.*}})
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp target parallel do simd if(target: .true.) if(parallel: .false.) &
!$omp& if(simd: .true.)
do i = 1, 10
@@ -342,7 +335,7 @@ program main
! CHECK: omp.parallel
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
! CHECK-NOT: if({{.*}})
! CHECK-SAME: {
!$omp target parallel do simd if(target: .true.)
@@ -355,8 +348,7 @@ program main
! CHECK-SAME: {
! CHECK: omp.parallel
! CHECK-SAME: if({{.*}})
- ! CHECK: omp.simdloop
- ! CHECK-SAME: if({{.*}})
+ ! CHECK: omp.wsloop
!$omp target parallel do simd if(parallel: .true.) if(simd: .false.)
do i = 1, 10
end do
diff --git a/flang/test/Lower/OpenMP/loop-combined.f90 b/flang/test/Lower/OpenMP/loop-combined.f90
index 960e9518127d75..70488b6a769ce4 100644
--- a/flang/test/Lower/OpenMP/loop-combined.f90
+++ b/flang/test/Lower/OpenMP/loop-combined.f90
@@ -23,7 +23,7 @@ program main
! ----------------------------------------------------------------------------
! DO SIMD
! ----------------------------------------------------------------------------
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
!$omp do simd
do i = 1, 10
end do
@@ -33,7 +33,7 @@ program main
! PARALLEL DO SIMD
! ----------------------------------------------------------------------------
! CHECK: omp.parallel
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
!$omp parallel do simd
do i = 1, 10
end do
@@ -54,7 +54,7 @@ program main
! ----------------------------------------------------------------------------
! CHECK: omp.target
! CHECK: omp.parallel
- ! CHECK: omp.simdloop
+ ! CHECK: omp.wsloop
!$omp target parallel do simd
do i = 1, 10
end do
``````````
</details>
https://github.com/llvm/llvm-project/pull/79559
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