https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110516
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-12 branch has been updated by Iain Buclaw <ibuc...@gcc.gnu.org>: https://gcc.gnu.org/g:b224692084e40aabcba1e73166eedf55dfd7f563 commit r12-9749-gb224692084e40aabcba1e73166eedf55dfd7f563 Author: Iain Buclaw <ibuc...@gdcproject.org> Date: Sun Jul 2 03:24:53 2023 +0200 d: Fix core.volatile.volatileLoad discarded if result is unused The first pass of code generation in the D front-end splits up all compound expressions and discards expressions that have no side effects. This included calls to the `volatileLoad' intrinsic if its result was not used, causing such calls to be eliminated from the program. We already set TREE_THIS_VOLATILE on the expression, however the tree documentation says if this bit is set in an expression, so is TREE_SIDE_EFFECTS. So set TREE_SIDE_EFFECTS on the expression too. This prevents any early discarding from occuring. PR d/110516 gcc/d/ChangeLog: * intrinsics.cc (expand_volatile_load): Set TREE_SIDE_EFFECTS on the expanded expression. (expand_volatile_store): Likewise. gcc/testsuite/ChangeLog: * gdc.dg/torture/pr110516a.d: New test. * gdc.dg/torture/pr110516b.d: New test. (cherry picked from commit 80ae426a195a0d035640a6301da833564deade52)
