From: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
To: linux-sparse@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Subject: [SPARSE 0/4] fix/improve canonicalization of signed compares
Date: Sun, 18 Apr 2021 17:32:29 +0200 [thread overview]
Message-ID: <20210418153233.45234-1-luc.vanoostenryck@gmail.com> (raw)
This series contains the following:
1) signed compares against a constant are now canonicalized towards 0
so that (x >= 0) doesn't become (x > -1)
2) a signed compare like (x >= 0 && x <= C) is simplified into the
unsigned compare: (x <= C)
This series is also available for review and testing at:
git://git.kernel.org/pub/scm/devel/sparse/sparse.git optim-and-cmp
Luc Van Oostenryck (4):
canonicalize constant signed compares toward zero
add testcases for AND(x > 0, x <= C) --> x u<= C
add helper is_positive()
simplify AND(x >= 0, x < C) --> (unsigned)x < C
linearize.h | 5 ++
simplify.c | 45 +++++++++++++---
validation/optim/canonical-cmp-zero.c | 74 +++++++++++++++++++++++++++
validation/optim/range-check1.c | 16 ++++++
validation/optim/range-check2.c | 14 +++++
5 files changed, 148 insertions(+), 6 deletions(-)
create mode 100644 validation/optim/canonical-cmp-zero.c
create mode 100644 validation/optim/range-check1.c
create mode 100644 validation/optim/range-check2.c
base-commit: eb4cdd21b7d0cedbbeff7f70e24473706ccce5a6
--
2.31.1
next reply other threads:[~2021-04-18 15:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-18 15:32 Luc Van Oostenryck [this message]
2021-04-18 15:32 ` [SPARSE 1/4] canonicalize constant signed compares toward zero Luc Van Oostenryck
2021-04-18 15:32 ` [SPARSE 2/4] add testcases for AND(x > 0, x <= C) --> x u<= C Luc Van Oostenryck
2021-04-18 15:32 ` [SPARSE 3/4] add helper is_positive() Luc Van Oostenryck
2021-04-18 15:32 ` [SPARSE 4/4] simplify AND(x >= 0, x < C) --> (unsigned)x < C Luc Van Oostenryck
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