[Bug tree-optimization/112818] [14 regression] ICE when building accel-ppp (error: conversion of register to a different size in ‘view_convert_expr’, verify_gimple failed) since r14-5068-g88aca917eb705b

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112818

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
So the issue is we're having

  _8 = __builtin_bswap16 (type_6(D));

with short _8 and int type_6 due to C argument promotion applied because
of promote_prototypes.

Since the arg is an external_def we could have done better and actually
demoted it but vectorizable_call decided on a vector type already.