• Type: Correctness / Copy-paste index bug
• Severity: High
• Component: BaseFab GPU search path
• Location: Src/Base/AMReX_BaseFab.H:2188

Problem

In the GPU branch of BaseFab<T>::indexFromValue, the returned IntVect is built as:

return IntVect(AMREX_D_DECL(ha[1],ha[2],ha[2]));

The third component should be ha[3], not ha[2]. This is a classic x/y/z copy-paste index error.

Impact

• In 3D GPU execution, the returned z-index can be wrong (it duplicates y).
• Can misidentify the located cell and propagate incorrect downstream logic.

Suggested patch

--- a/Src/Base/AMReX_BaseFab.H
+++ b/Src/Base/AMReX_BaseFab.H
@@
-        return IntVect(AMREX_D_DECL(ha[1],ha[2],ha[2]));
+        return IntVect(AMREX_D_DECL(ha[1],ha[2],ha[3]));

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