[Flang] Fix perfect loop nest detection #161554
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
llvmbot
added
flang
|
@llvm/pr-subscribers-flang-openmp Author: Michael Kruse (Meinersbur) ChangesPR #160283 uses Fixes #161529 Full diff: https://github.com/llvm/llvm-project/pull/161554.diff 4 Files Affected:
diff --git a/flang/lib/Semantics/resolve-directives.cpp b/flang/lib/Semantics/resolve-directives.cpp
index bd7b8ac552fab..d32fa3eedae21 100644
--- a/flang/lib/Semantics/resolve-directives.cpp
+++ b/flang/lib/Semantics/resolve-directives.cpp
@@ -2303,14 +2303,17 @@ void OmpAttributeVisitor::CheckPerfectNestAndRectangularLoop(
}
auto checkPerfectNest = [&, this]() {
- auto blockSize = block.size();
- if (blockSize <= 1)
+ if (block.empty())
return;
+ auto last = block.end();
+ --last;
- if (parser::Unwrap<parser::ContinueStmt>(x))
- blockSize -= 1;
+ // A trailing CONTINUE or CYCLE does not belong to the loop body
+ if (parser::Unwrap<parser::ContinueStmt>(*last))
+ --last;
- if (blockSize <= 1)
+ // In a perfectly nested loop, the nested loop must be the only statement
+ if (last == block.begin())
return;
// Non-perfectly nested loop
diff --git a/flang/test/Lower/OpenMP/wsloop-collapse-continue.f90 b/flang/test/Lower/OpenMP/wsloop-collapse-continue.f90
new file mode 100644
index 0000000000000..fea7a8b335d63
--- /dev/null
+++ b/flang/test/Lower/OpenMP/wsloop-collapse-continue.f90
@@ -0,0 +1,19 @@
+! RUN: bbc -fopenmp -emit-hlfir %s -o - | FileCheck %s
+
+program wsloop_collapse_continue
+ integer i, j
+
+! CHECK: omp.wsloop {{.*}} {
+! CHECK: omp.loop_nest ({{.*}}) : i32 = ({{.*}}) to ({{.*}}) inclusive step ({{.*}}) collapse(2) {
+ !$omp do collapse(2)
+ do 50 i = 1, 42
+ do 51 j = 1, 84
+! CHECK: fir.call @_FortranAioOutputInteger32(
+ print *, i
+! CHECK: fir.call @_FortranAioOutputInteger32(
+ print *, j
+ 51 continue
+ 50 continue
+ !$omp end do
+
+end program wsloop_collapse_continue
diff --git a/flang/test/Semantics/OpenMP/do08.f90 b/flang/test/Semantics/OpenMP/do08.f90
index bb3c1d0cd3855..5143dff0dd315 100644
--- a/flang/test/Semantics/OpenMP/do08.f90
+++ b/flang/test/Semantics/OpenMP/do08.f90
@@ -61,7 +61,6 @@ program omp
!$omp end do
- !ERROR: Canonical loop nest must be perfectly nested.
!ERROR: The value of the parameter in the COLLAPSE or ORDERED clause must not be larger than the number of nested loops following the construct.
!$omp do collapse(3)
do 60 i=2,200,2
diff --git a/flang/test/Semantics/OpenMP/do13.f90 b/flang/test/Semantics/OpenMP/do13.f90
index 8f7844f4136f9..6e9d1dddade4c 100644
--- a/flang/test/Semantics/OpenMP/do13.f90
+++ b/flang/test/Semantics/OpenMP/do13.f90
@@ -59,7 +59,6 @@ program omp
!$omp end do
- !ERROR: Canonical loop nest must be perfectly nested.
!ERROR: The value of the parameter in the COLLAPSE or ORDERED clause must not be larger than the number of nested loops following the construct.
!$omp do collapse(3)
do 60 i=1,10
|
|
@llvm/pr-subscribers-flang-fir-hlfir Author: Michael Kruse (Meinersbur) ChangesPR #160283 uses Fixes #161529 Full diff: https://github.com/llvm/llvm-project/pull/161554.diff 4 Files Affected:
diff --git a/flang/lib/Semantics/resolve-directives.cpp b/flang/lib/Semantics/resolve-directives.cpp
index bd7b8ac552fab..d32fa3eedae21 100644
--- a/flang/lib/Semantics/resolve-directives.cpp
+++ b/flang/lib/Semantics/resolve-directives.cpp
@@ -2303,14 +2303,17 @@ void OmpAttributeVisitor::CheckPerfectNestAndRectangularLoop(
}
auto checkPerfectNest = [&, this]() {
- auto blockSize = block.size();
- if (blockSize <= 1)
+ if (block.empty())
return;
+ auto last = block.end();
+ --last;
- if (parser::Unwrap<parser::ContinueStmt>(x))
- blockSize -= 1;
+ // A trailing CONTINUE or CYCLE does not belong to the loop body
+ if (parser::Unwrap<parser::ContinueStmt>(*last))
+ --last;
- if (blockSize <= 1)
+ // In a perfectly nested loop, the nested loop must be the only statement
+ if (last == block.begin())
return;
// Non-perfectly nested loop
diff --git a/flang/test/Lower/OpenMP/wsloop-collapse-continue.f90 b/flang/test/Lower/OpenMP/wsloop-collapse-continue.f90
new file mode 100644
index 0000000000000..fea7a8b335d63
--- /dev/null
+++ b/flang/test/Lower/OpenMP/wsloop-collapse-continue.f90
@@ -0,0 +1,19 @@
+! RUN: bbc -fopenmp -emit-hlfir %s -o - | FileCheck %s
+
+program wsloop_collapse_continue
+ integer i, j
+
+! CHECK: omp.wsloop {{.*}} {
+! CHECK: omp.loop_nest ({{.*}}) : i32 = ({{.*}}) to ({{.*}}) inclusive step ({{.*}}) collapse(2) {
+ !$omp do collapse(2)
+ do 50 i = 1, 42
+ do 51 j = 1, 84
+! CHECK: fir.call @_FortranAioOutputInteger32(
+ print *, i
+! CHECK: fir.call @_FortranAioOutputInteger32(
+ print *, j
+ 51 continue
+ 50 continue
+ !$omp end do
+
+end program wsloop_collapse_continue
diff --git a/flang/test/Semantics/OpenMP/do08.f90 b/flang/test/Semantics/OpenMP/do08.f90
index bb3c1d0cd3855..5143dff0dd315 100644
--- a/flang/test/Semantics/OpenMP/do08.f90
+++ b/flang/test/Semantics/OpenMP/do08.f90
@@ -61,7 +61,6 @@ program omp
!$omp end do
- !ERROR: Canonical loop nest must be perfectly nested.
!ERROR: The value of the parameter in the COLLAPSE or ORDERED clause must not be larger than the number of nested loops following the construct.
!$omp do collapse(3)
do 60 i=2,200,2
diff --git a/flang/test/Semantics/OpenMP/do13.f90 b/flang/test/Semantics/OpenMP/do13.f90
index 8f7844f4136f9..6e9d1dddade4c 100644
--- a/flang/test/Semantics/OpenMP/do13.f90
+++ b/flang/test/Semantics/OpenMP/do13.f90
@@ -59,7 +59,6 @@ program omp
!$omp end do
- !ERROR: Canonical loop nest must be perfectly nested.
!ERROR: The value of the parameter in the COLLAPSE or ORDERED clause must not be larger than the number of nested loops following the construct.
!$omp do collapse(3)
do 60 i=1,10
|
|
@llvm/pr-subscribers-flang-semantics Author: Michael Kruse (Meinersbur) ChangesPR #160283 uses Fixes #161529 Full diff: https://github.com/llvm/llvm-project/pull/161554.diff 4 Files Affected:
diff --git a/flang/lib/Semantics/resolve-directives.cpp b/flang/lib/Semantics/resolve-directives.cpp
index bd7b8ac552fab..d32fa3eedae21 100644
--- a/flang/lib/Semantics/resolve-directives.cpp
+++ b/flang/lib/Semantics/resolve-directives.cpp
@@ -2303,14 +2303,17 @@ void OmpAttributeVisitor::CheckPerfectNestAndRectangularLoop(
}
auto checkPerfectNest = [&, this]() {
- auto blockSize = block.size();
- if (blockSize <= 1)
+ if (block.empty())
return;
+ auto last = block.end();
+ --last;
- if (parser::Unwrap<parser::ContinueStmt>(x))
- blockSize -= 1;
+ // A trailing CONTINUE or CYCLE does not belong to the loop body
+ if (parser::Unwrap<parser::ContinueStmt>(*last))
+ --last;
- if (blockSize <= 1)
+ // In a perfectly nested loop, the nested loop must be the only statement
+ if (last == block.begin())
return;
// Non-perfectly nested loop
diff --git a/flang/test/Lower/OpenMP/wsloop-collapse-continue.f90 b/flang/test/Lower/OpenMP/wsloop-collapse-continue.f90
new file mode 100644
index 0000000000000..fea7a8b335d63
--- /dev/null
+++ b/flang/test/Lower/OpenMP/wsloop-collapse-continue.f90
@@ -0,0 +1,19 @@
+! RUN: bbc -fopenmp -emit-hlfir %s -o - | FileCheck %s
+
+program wsloop_collapse_continue
+ integer i, j
+
+! CHECK: omp.wsloop {{.*}} {
+! CHECK: omp.loop_nest ({{.*}}) : i32 = ({{.*}}) to ({{.*}}) inclusive step ({{.*}}) collapse(2) {
+ !$omp do collapse(2)
+ do 50 i = 1, 42
+ do 51 j = 1, 84
+! CHECK: fir.call @_FortranAioOutputInteger32(
+ print *, i
+! CHECK: fir.call @_FortranAioOutputInteger32(
+ print *, j
+ 51 continue
+ 50 continue
+ !$omp end do
+
+end program wsloop_collapse_continue
diff --git a/flang/test/Semantics/OpenMP/do08.f90 b/flang/test/Semantics/OpenMP/do08.f90
index bb3c1d0cd3855..5143dff0dd315 100644
--- a/flang/test/Semantics/OpenMP/do08.f90
+++ b/flang/test/Semantics/OpenMP/do08.f90
@@ -61,7 +61,6 @@ program omp
!$omp end do
- !ERROR: Canonical loop nest must be perfectly nested.
!ERROR: The value of the parameter in the COLLAPSE or ORDERED clause must not be larger than the number of nested loops following the construct.
!$omp do collapse(3)
do 60 i=2,200,2
diff --git a/flang/test/Semantics/OpenMP/do13.f90 b/flang/test/Semantics/OpenMP/do13.f90
index 8f7844f4136f9..6e9d1dddade4c 100644
--- a/flang/test/Semantics/OpenMP/do13.f90
+++ b/flang/test/Semantics/OpenMP/do13.f90
@@ -59,7 +59,6 @@ program omp
!$omp end do
- !ERROR: Canonical loop nest must be perfectly nested.
!ERROR: The value of the parameter in the COLLAPSE or ORDERED clause must not be larger than the number of nested loops following the construct.
!$omp do collapse(3)
do 60 i=1,10
|
Meinersbur
commented
Oct 1, 2025
| !$omp end do | ||
|
|
||
|
|
||
| !ERROR: Canonical loop nest must be perfectly nested. |
There was a problem hiding this comment.
These ERRORs were added in #60283. Those are still non-perfectly nested loops, but the other errors get precedence.
ronlieb
approved these changes
Oct 1, 2025
searlmc1
pushed a commit
to ROCm/llvm-project
that referenced
this pull request
Oct 2, 2025
PR llvm#160283 uses `Unwrap` to detect a `continue` statement, but it applied it on the loop body itelf which sometimes finds a trailing continue statement, but not always. Apply `Unwrap` on the last body statement instead, where the `continue` is expected. Fixes llvm#161529
mahesh-attarde
pushed a commit
to mahesh-attarde/llvm-project
that referenced
this pull request
Oct 3, 2025
PR llvm#160283 uses `Unwrap` to detect a `continue` statement, but it applied it on the loop body itelf which sometimes finds a trailing continue statement, but not always. Apply `Unwrap` on the last body statement instead, where the `continue` is expected. Fixes llvm#161529
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
PR #160283 uses
Unwrapto detect acontinuestatement, but it applied it on the loop body itelf which sometimes finds a trailing continue statement, but not always. ApplyUnwrapon the last body statement instead, where thecontinueis expected.Fixes #161529