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[libgfortran, patch] Remove runtime clz() and ctz() bit intrisic functions

From: FX <fxcoudert at gmail dot com>
To: GCC-Fortran-ML <fortran at gcc dot gnu dot org>
Cc: gcc-patches <gcc-patches at gcc dot gnu dot org>, Janne Blomqvist <blomqvist dot janne at gmail dot com>
Date: Mon, 19 Dec 2016 15:48:37 +0100
Subject: [libgfortran, patch] Remove runtime clz() and ctz() bit intrisic functions
Authentication-results: sourceware.org; auth=none

We implement the LEADZ and TRAILZ intrinsics in terms of the built-in clz() and ctz() functions. Since these are not available for 128-bit integer types, we used to have support functions _gfortran_clz128() and _gfortran_ctz128() in libgfortran. In 2010, I applied a patch to avoid this and emit the necessary arithmetic directly from the front-end (https://gcc.gnu.org/ml/fortran/2010-09/msg00181.html). The support functions were kept in libgfortran for backward compatibility, but we can now remove them as we break the ABI.

Attached patch is bootstrapped and regtested on x86_64-apple-darwin13.6.0.
OK to commit?

FX

Attachment: bitint.ChangeLog
Description: Binary data

Attachment: bitint.diff
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