https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82391
Bug ID: 82391
Summary: [openacc] acc_on_device not folded at -O0
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libgomp
Assignee: unassigned at gcc dot gnu.org
Reporter: vries at gcc dot gnu.org
CC: jakub at gcc dot gnu.org
Target Milestone: ---
The openacc spec states: "If the acc_on_device routine has a compile-time
constant argument, it evaluates at compile time to a constant."
This is not the case at -O0.
At f.i. -O2, the folding is done by gimple_fold_builtin_acc_on_device. This
folds the builtin for all arguments, not just constant. Further
optimizations/folding propagate the constant argument to a situation where the
the acc_on_device routine is reduced to a compile time constant.
