Correct. It is truncated for integer shift, but not simd shift instructions. We generate a pattern in the split that only generates the integer shift instructions.
-----Original Message----- From: Richard Kenner [mailto:[email protected]] Sent: Tuesday, August 8, 2017 1:04 PM To: Michael Collison <[email protected]> Cc: [email protected]; nd <[email protected]>; [email protected] Subject: RE: [PATCH] [Aarch64] Optimize subtract in shift counts > Because for integer shift instructions the shift count is truncated. > We ensure that we only use integer shift instructions by emitting a > shift with a mask. This only matches integer shift instructions in the > md file. That's why I asked about SHIFT_COUNT_TRUNCATED. So it's truncated for some shifts, but not all?
