[flang-commits] [PATCH] D151737: [flang] Don't fold SIZE()/SHAPE() into expression referencing optional dummy arguments

[Peter Klausler via Phabricator via flang-commits]

klausler created this revision.
klausler added a reviewer: vzakhari.
klausler added a project: Flang.
Herald added subscribers: sunshaoce, jdoerfert.
Herald added a reviewer: sscalpone.
Herald added a project: All.
klausler requested review of this revision.

When computing the shape of an expression at compilation time as part of  
folding an intrinsic function like SIZE(), don't create an expression that
increases a dependence on the presence of an optional dummy argument.


https://reviews.llvm.org/D151737

Files:
  flang/lib/Evaluate/shape.cpp
  flang/test/Evaluate/elem-shape.f90


Index: flang/test/Evaluate/elem-shape.f90
===================================================================
--- /dev/null
+++ flang/test/Evaluate/elem-shape.f90
@@ -0,0 +1,16 @@
+! RUN: %flang_fc1 -fdebug-unparse %s 2>&1 | FileCheck %s
+! Ensure that optional arguments aren't used to fold SIZE() or SHAPE()
+module m
+ contains
+  subroutine sub(x,y)
+    real :: x(:), y(:)
+    optional x
+    !CHECK: PRINT *, int(size(y,dim=1,kind=8),kind=4)
+    print *, size(f(x,y))
+  end
+  elemental function f(x,y)
+    real, intent(in) :: x, y
+    optional x
+    f = y
+  end
+end
Index: flang/lib/Evaluate/shape.cpp
===================================================================
--- flang/lib/Evaluate/shape.cpp
+++ flang/lib/Evaluate/shape.cpp
@@ -805,9 +805,19 @@
   if (call.Rank() == 0) {
     return ScalarShape();
   } else if (call.IsElemental()) {
-    for (const auto &arg : call.arguments()) {
-      if (arg && arg->Rank() > 0) {
-        return (*this)(*arg);
+    // Use the shape of an actual array argument associated with a
+    // non-OPTIONAL dummy object argument.
+    if (context_) {
+      if (auto chars{characteristics::Procedure::FromActuals(
+              call.proc(), call.arguments(), *context_)}) {
+        std::size_t j{0};
+        for (const auto &arg : call.arguments()) {
+          if (arg && arg->Rank() > 0 && j < chars->dummyArguments.size() &&
+              !chars->dummyArguments[j].IsOptional()) {
+            return (*this)(*arg);
+          }
+          ++j;
+        }
       }
     }
     return ScalarShape();


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D151737.526714.patch
Type: text/x-patch
Size: 1566 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/flang-commits/attachments/20230530/5a6ef298/attachment-0001.bin>