loop metadata: add two more test cases and improve loop discovery

Those two test cases were supposed to be contributed to PR #1094. Unfortunately, at that time, the -emit-flang-llvm flag was not supported by the frontend driver yet. One of those tests was failing make-check testing. It turned out, flang failed to recognize one of the loops. A small change had to be backported in order to improve the situation. Signed-off-by: Paul Osmialowski <[email protected]>
flang-compiler · Oct 18, 2023 · 89b7ac6 · 89b7ac6
1 parent 762e596
commit 89b7ac6
Show file tree

Hide file tree

Showing 4 changed files with 213 additions and 10 deletions.
diff --git a/test/llvm_ir_correct/loop-line-metadata.f90 b/test/llvm_ir_correct/loop-line-metadata.f90
@@ -0,0 +1,60 @@
+! Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+! See https://llvm.org/LICENSE.txt for license information.
+! SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+! REQUIRES: llvm-13
+
+! RUN: %flang -g -O2 -emit-flang-llvm %s -o /dev/stdout | FileCheck %s
+
+! Test that with debug metadata enabled, in the absence of loop pragmas, loops
+! get annotated with their start and end line numbers.
+
+! CHECK: test_loop_line_md
+subroutine test_loop_line_md(x, N)
+  integer, intent(out) :: x
+
+  do i = 1, N
+  ! CHECK-DAG: ![[L1Start:[0-9]+]] = !DILocation(line: [[@LINE-1]],
+  ! CHECK-DAG: ![[L1End:[0-9]+]] = !DILocation(line: [[@LINE+4]],
+    x = x + i + 1
+  ! CHECK-DAG: br {{.*}}, !llvm.loop ![[L1:[0-9]+]]
+  ! CHECK-DAG: ![[L1]] = !{ ![[L1]],{{.*}}![[L1Start]], ![[L1End]]
+  end do
+
+  do i = 1, N
+  ! CHECK-DAG: ![[L2Start:[0-9]+]] = !DILocation(line: [[@LINE-1]],
+  ! CHECK-DAG: ![[L2End:[0-9]+]] = !DILocation(line: [[@LINE+11]],
+
+    do j = 1, N
+    ! CHECK-DAG: ![[L3Start:[0-9]+]] = !DILocation(line: [[@LINE-1]],
+    ! CHECK-DAG: ![[L3End:[0-9]+]] = !DILocation(line: [[@LINE+4]],
+      x = x + j + i + 1
+    ! CHECK-DAG: br {{.*}}, !llvm.loop ![[L3:[0-9]+]]
+    ! CHECK-DAG: ![[L3]] = !{ ![[L3]],{{.*}}![[L3Start]], ![[L3End]]
+    end do
+  ! CHECK-DAG: br {{.*}}, !llvm.loop ![[L2:[0-9]+]]
+  ! CHECK-DAG: ![[L2]] = !{ ![[L2]],{{.*}}![[L2Start]], ![[L2End]]
+  end do
+
+  ! There should be no further loop metadata.
+  ! CHECK-NOT: !llvm.loop
+end subroutine
+
+! CHECK: test_implicit_loop_intrinsic
+subroutine test_implicit_loop_intrinsic(x, arr)
+  integer :: arr(:)
+  integer, intent(out) :: x
+  x = sum(arr)
+! NOTE: You might expect this to have an llvm.loop, but it does not at the
+! moment, because the loop does not get marked with BIH_HEAD.
+! CHECK-NOT: !llvm.loop
+end subroutine
+
+! CHECK: test_implicit_loop_array_op
+subroutine test_implicit_loop_array_op(arr)
+  integer :: arr(:)
+  arr = 3
+! NOTE: You might expect this to have an llvm.loop, but it does not at the
+! moment, because the loop does not get marked with BIH_HEAD.
+! CHECK-NOT: !llvm.loop
+end subroutine
diff --git a/test/llvm_ir_correct/loop-pragmas-and-line-metadata.f90 b/test/llvm_ir_correct/loop-pragmas-and-line-metadata.f90
@@ -0,0 +1,150 @@
+! Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+! See https://llvm.org/LICENSE.txt for license information.
+! SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+! REQUIRES: llvm-13
+
+! RUN: %flang -g -fopenmp -O2 -emit-flang-llvm %s -o /dev/stdout \
+! RUN:   | FileCheck --check-prefixes=CHECK,CHECK-LINE %s
+
+! RUN: %flang -g -fopenmp -O2 -emit-flang-llvm %s -o /dev/stdout \
+! RUN:   | FileCheck --check-prefixes=CHECK,CHECK-DIRS %s
+
+! Test that loop metadata is correct for a variety of loops.
+!
+! This file tests two properties of the metadata:
+!
+! * CHECK -LINE: Check the line number metadata associated with the loop refers
+!               to the correct source lines.
+! * CHECK -DIRS: Check that directives associated with the loop are the correct ones.
+!
+! This is done as two separate runs to avoid being sensitive to the order of
+! metadata nodes within the loop ID.
+!
+! The strategy is to locate the DILocation nodes for the start and end of the
+! loop using @LINE, then locate the !llvm.loop node on a branch, then check
+! that the contents of the loop ID are as expected.
+!
+! The test also enforces that the expected number of !llvm.loop directives are
+! present.
+
+! CHECK: test_loop_line_md
+subroutine test_loop_line_md(x, N)
+  integer, intent(out) :: x
+
+  ! CHECK-DIRS-DAG: ![[VEC_ON:[0-9]+]] = !{ !"llvm.loop.vectorize.enable", i1 1 }
+  ! CHECK-DIRS-DAG: ![[VEC_OFF:[0-9]+]] = !{ !"llvm.loop.vectorize.enable", i1 0 }
+  ! CHECK-DIRS-DAG: ![[UNROLL_ON:[0-9]+]] = !{ !"llvm.loop.unroll.enable" }
+  ! CHECK-DIRS-DAG: ![[UNROLL_OFF:[0-9]+]] = !{ !"llvm.loop.unroll.disable" }
+
+  !dir$ novector
+  do i = 1, N
+  ! CHECK-LINE-DAG: ![[L1Start:[0-9]+]] = !DILocation(line: [[@LINE-1]],
+  ! CHECK-LINE-DAG: ![[L1End:[0-9]+]] = !DILocation(line: [[@LINE+7]],
+    x = x + i + 1
+  ! NOTE: The first one of these is redundant.
+  ! CHECK-DAG: br {{.*}}, !llvm.loop !{{[0-9]+}}
+  ! CHECK-DAG: br {{.*}}, !llvm.loop ![[L1:[0-9]+]]
+  ! CHECK-LINE-DAG: ![[L1]] = !{ ![[L1]],{{.*}}![[L1Start]], ![[L1End]]
+  ! CHECK-DIRS-DAG: ![[L1]] = !{ ![[L1]],{{.*}}![[VEC_OFF]]{{[, ]}}
+  end do
+
+  !dir$ vector always
+  do i = 1, Nq
+  ! CHECK-LINE-DAG: ![[L2Start:[0-9]+]] = !DILocation(line: [[@LINE-1]],
+  ! CHECK-LINE-DAG: ![[L2End:[0-9]+]] = !DILocation(line: [[@LINE+7]],
+    x = x + i + 1
+  ! NOTE: The first one of these is redundant.
+  ! CHECK-DAG: br {{.*}}, !llvm.loop !{{[0-9]+}}
+  ! CHECK-DAG: br {{.*}}, !llvm.loop ![[L2:[0-9]+]]
+  ! CHECK-LINE-DAG: ![[L2]] = !{ ![[L2]],{{.*}}![[L2Start]], ![[L2End]]
+  ! CHECK-DIRS-DAG: ![[L2]] = !{ ![[L2]],{{.*}}![[VEC_ON]]{{[, ]}}
+  end do
+
+  !dir$ nounroll
+  do i = 1, N
+  ! CHECK-LINE-DAG: ![[L3Start:[0-9]+]] = !DILocation(line: [[@LINE-1]],
+  ! CHECK-LINE-DAG: ![[L3End:[0-9]+]] = !DILocation(line: [[@LINE+7]],
+    x = x + i + 1
+  ! NOTE: The first one of these is redundant.
+  ! CHECK-DAG: br {{.*}}, !llvm.loop !{{[0-9]+}}
+  ! CHECK-DAG: br {{.*}}, !llvm.loop ![[L3:[0-9]+]]
+  ! CHECK-LINE-DAG: ![[L3]] = !{ ![[L3]],{{.*}}![[L3Start]], ![[L3End]],
+  ! CHECK-DIRS-DAG: ![[L3]] = !{ ![[L3]],{{.*}}![[UNROLL_OFF]]{{[, ]}}
+  end do
+
+  !dir$ unroll
+  do i = 1, N
+  ! CHECK-LINE-DAG: ![[L4Start:[0-9]+]] = !DILocation(line: [[@LINE-1]],
+  ! CHECK-LINE-DAG: ![[L4End:[0-9]+]] = !DILocation(line: [[@LINE+7]],
+    x = x + i + 1
+  ! NOTE: The first one of these is redundant.
+  ! CHECK-DAG: br {{.*}}, !llvm.loop !{{[0-9]+}}
+  ! CHECK-DAG: br {{.*}}, !llvm.loop ![[L4:[0-9]+]]
+  ! CHECK-LINE-DAG: ![[L4]] = !{ ![[L4]],{{.*}}![[L4Start]], ![[L4End]],
+  ! CHECK-DIRS-DAG: ![[L4]] = !{ ![[L4]],{{.*}}![[UNROLL_ON]]{{[, ]}}
+  end do
+
+  !dir$ nounroll
+  do i = 1, N
+  ! CHECK-LINE-DAG: ![[L5Start:[0-9]+]] = !DILocation(line: [[@LINE-1]],
+  ! CHECK-LINE-DAG: ![[L5End:[0-9]+]] = !DILocation(line: [[@LINE+7]],
+    x = x + i + 1
+  ! NOTE: The first one of these is redundant.
+  ! CHECK-DAG: br {{.*}}, !llvm.loop !{{[0-9]+}}
+  ! CHECK-DAG: br {{.*}}, !llvm.loop ![[L5:[0-9]+]]
+  ! CHECK-LINE-DAG: ![[L5]] = !{ ![[L5]],{{.*}}![[L5Start]], ![[L5End]],
+  ! CHECK-DIRS-DAG: ![[L5]] = !{ ![[L5]],{{.*}}![[UNROLL_OFF]]{{[, ]}}
+  end do
+
+  !dir$ unroll
+  do i = 1, N
+  ! CHECK-LINE-DAG: ![[L5Start:[0-9]+]] = !DILocation(line: [[@LINE-1]],
+  ! CHECK-LINE-DAG: ![[L5End:[0-9]+]] = !DILocation(line: [[@LINE+7]],
+    x = x + i + 1
+  ! NOTE: The first one of these is redundant.
+  ! CHECK-DAG: br {{.*}}, !llvm.loop !{{[0-9]+}}
+  ! CHECK-DAG: br {{.*}}, !llvm.loop ![[L5:[0-9]+]]
+  ! CHECK-LINE-DAG: ![[L5]] = !{ ![[L5]],{{.*}}![[L5Start]], ![[L5End]],
+  ! CHECK-DIRS-DAG: ![[L5]] = !{ ![[L5]],{{.*}}![[UNROLL_ON]]{{[, ]}}
+  end do
+
+  !$omp simd
+  do i = 1, N
+  ! CHECK-LINE-DAG: ![[L7Start:[0-9]+]] = !DILocation(line: [[@LINE-1]],
+  ! CHECK-LINE-DAG: ![[L7End:[0-9]+]] = !DILocation(line: [[@LINE+7]],
+    x = x + i + 1
+  ! NOTE: The first one of these is redundant.
+  ! CHECK-DAG: br {{.*}}, !llvm.loop !{{[0-9]+}}
+  ! CHECK-DAG: br {{.*}}, !llvm.loop ![[L7:[0-9]+]]
+  ! CHECK-LINE-DAG: ![[L7]] = !{ ![[L7]],{{.*}}![[L7Start]], ![[L7End]]
+  ! CHECK-DIRS-DAG: ![[L7]] = !{ ![[L7]],{{.*}}![[VEC_ON]]{{[, ]}}
+  end do
+
+  !dir$ novector
+  do i = 1, N
+  ! CHECK-LINE-DAG: ![[L8Start:[0-9]+]] = !DILocation(line: [[@LINE-1]],
+  ! CHECK-LINE-DAG: ![[L8End:[0-9]+]] = !DILocation(line: [[@LINE+7]],
+    x = x + i + 1
+  ! NOTE: This test is missing the redundant llvm.loop instruction because the
+  ! previous one uses the !$omp simd directive. This is weird.
+  ! CHECK-DAG: br {{.*}}, !llvm.loop ![[L8:[0-9]+]]
+  ! CHECK-LINE-DAG: ![[L8]] = !{ ![[L8]],{{.*}}![[L8Start]], ![[L8End]]
+  ! CHECK-DIRS-DAG: ![[L8]] = !{ ![[L8]],{{.*}}![[VEC_OFF]]{{[, ]}}
+  end do
+
+  !dir$ vector always
+  do i = 1, N
+  ! CHECK-LINE-DAG: ![[L9Start:[0-9]+]] = !DILocation(line: [[@LINE-1]],
+  ! CHECK-LINE-DAG: ![[L9End:[0-9]+]] = !DILocation(line: [[@LINE+7]],
+    x = x + i + 1
+  ! NOTE: The first one of these is redundant.
+  ! CHECK-DAG: br {{.*}}, !llvm.loop !{{[0-9]+}}
+  ! CHECK-DAG: br {{.*}}, !llvm.loop ![[L9:[0-9]+]]
+  ! CHECK-LINE-DAG: ![[L9]] = !{ ![[L9]],{{.*}}![[L9Start]], ![[L9End]]
+  ! CHECK-DIRS-DAG: ![[L9]] = !{ ![[L9]],{{.*}}![[VEC_ON]]{{[, ]}}
+  end do
+
+  ! There should be no further loop metadata.
+  ! CHECK-NOT: !llvm.loop
+end subroutine
diff --git a/tools/flang2/flang2exe/cgmain.cpp b/tools/flang2/flang2exe/cgmain.cpp
@@ -1794,8 +1794,8 @@ schedule(void)
         }
 
         if ((!XBIT(69, 0x100000) && BIH_NODEPCHK(bih) && !BIH_NODEPCHK2(bih) &&
-             !ignore_simd_block(bih)) ||
-            BIH_SIMD(bih)) {
+             !ignore_simd_block(bih)) || BIH_SIMD(bih) ||
+            check_for_loop_directive(ILT_LINENO(ilt), 191, 0x4)) {
           if (LL_MDREF_IS_NULL(loop_md))
             loop_md = cons_loop_id_md();
 
@@ -1804,14 +1804,6 @@ schedule(void)
           // metadata once.
           (void)cons_vec_always_metadata();
         }
-        if ((check_for_loop_directive(ILT_LINENO(ilt), 191, 0x4))) {
-          LL_MDRef loop_md = cons_vec_always_metadata();
-          INSTR_LIST *i = find_last_executable(llvm_info.last_instr);
-          if (i) {
-            i->flags |= LOOP_BACKEDGE_FLAG;
-            i->misc_metadata = loop_md;
-          }
-        }
 
         if (BIH_VECTORLENGTH_ENABLED(bih)) {
           if (LL_MDREF_IS_NULL(loop_md)) {

diff --git a/tools/shared/pragma.c b/tools/shared/pragma.c
@@ -723,6 +723,7 @@ do_sw(void)
           assn(DIR_OFFSET(currdir, x[235]), num);
         } else if (strcmp(ctok, "always") == 0) {
           bclr(DIR_OFFSET(currdir, x[19]), 0x18);
+          bset(DIR_OFFSET(currdir, x[19]), 0x400);
           bset(DIR_OFFSET(currdir, x[191]), 0x4);
         } else {
           backup_nowarn = gbl.nowarn;