[Flang] Shift the data from lower to higher order bits in the big endian environment

[madanial0]

Shift the data from lower to higher order bits when memcpy the value in the namelist in the big endian environment

[llvmbot]

@llvm/pr-subscribers-flang-runtime

Author: None (madanial0)

Changes

Shift the data from lower to higher order bits when memcpy the value in the namelist in the big endian environment

---

Full diff: https://github.com/llvm/llvm-project/pull/73670.diff

1 Files Affected:

• (modified) flang/runtime/edit-input.cpp (+9-1)

diff --git a/flang/runtime/edit-input.cpp b/flang/runtime/edit-input.cpp
index 4e8c9aa868a691c..305d85afe480ffe 100644
--- a/flang/runtime/edit-input.cpp
+++ b/flang/runtime/edit-input.cpp
@@ -222,7 +222,15 @@ bool EditIntegerInput(
     value = -value;
   }
   if (any || !io.GetConnectionState().IsAtEOF()) {
-    std::memcpy(n, &value, kind); // a blank field means zero
+    // For integer kind <= 4, the value is stored in the lower order bits on
+    // the big endian platform. When memcpy the value, shift the value, shift
+    // the value to the higher order bit.
+    if (!isHostLittleEndian && kind <= 4) {
+      auto l{value.low() << (8 * (sizeof(value.low()) - kind))};
+      std::memcpy(n, &l, kind);
+    } else {
+      std::memcpy(n, &value, kind); // a blank field means zero
+    }
   }
   return any;
 }

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[madanial0]

friendly ping! Thanks!

[madanial0]

Friendly ping! Thanks!

[madanial0]

Thanks for the review!