https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112877
Bug ID: 112877
Summary: TARGET_PROMOTE_PROTOTYPES is not honored consistently,
should maybe not apply to builtins
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: rguenth at gcc dot gnu.org
Target Milestone: ---
Currently only the C, C++ and Ada frontends honor (maybe partly)
TARGET_PROMOTE_PROTOTYPES so this is at most an optimization feature,
in particular it doesn't look like the target can guarantee ABI constraints
with this (zero/sign extending arguments at callers).
TARGET_PROMOTE_PROTOTYPES should be (and is AFAICS) reflected into
DECL_ARG_TYPE.
combine is the only thing lookig at DECL_ARG_TYPE.
The iq2000, microblaze and PA targets look at DECL_ARG_TYPE (didn't look
at what).
In particular the vectorizer is pessimized by the promotion when
vectorizing builtins working on < int arguments and for OMP SIMD
function vectorization. Targets might get more control when
the hook were passed a function decl rather than only a function type.
But since nothing on the GIMPLE level cares about DECL_ARG_TYPE
it might be possible to reflect TARGET_PROMOTE_PROTOTYPES only during
RTL expansion.
