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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug rtl-optimization/97607] Spurious sign extension
Date: Wed, 28 Oct 2020 09:44:57 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D97607

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Target|                            |x86_64-linux
   Last reconfirmed|                            |2020-10-28
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
This is the TARGET_PROMOTE_PROTOTYPES target hook at play, directing the FE=
s to
emit the sign-extension and RTL expansion failing to elide it.  Note the
x86 ABI does _not_ specify the incoming argument is sign-extended so it only
works for functions where all calls are generated by GCC.

IMHO TARGET_PROMOTE_PROTOTYPES should go away.=