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From: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
To: Dibyendu Majumdar <mobile@majumdar.org.uk>
Cc: linux-sparse@vger.kernel.org,
	Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Subject: [PATCH v2 8/8] fix: cast of OP_AND only valid if it's an OP_CAST
Date: Mon,  7 Aug 2017 21:12:05 +0200	[thread overview]
Message-ID: <20170807191205.86590-9-luc.vanoostenryck@gmail.com> (raw)
In-Reply-To: <20170807191205.86590-1-luc.vanoostenryck@gmail.com>

A cast of an OP_AND can be simplified away if the mask
already 'cover' the value.
However this cannot be done if the cast is in fact
a sign-extension.

Fix this by adding the appropriate check of OP_CAST vs. OP_SCAST

Fixes: caeaf72d34d1e91aaea7340241232d1d877907b7
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
---
 simplify.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/simplify.c b/simplify.c
index cdc244c17..4da8edfde 100644
--- a/simplify.c
+++ b/simplify.c
@@ -1044,7 +1044,7 @@ static int simplify_cast(struct instruction *insn)
 	}
 
 	/* A cast of a "and" might be a no-op.. */
-	if (def_opcode(src) == OP_AND) {
+	if (insn->opcode == OP_CAST && def_opcode(src) == OP_AND) {
 		struct instruction *def = src->def;
 		if (def->size >= size) {
 			pseudo_t val = def->src2;
-- 
2.13.2


      parent reply	other threads:[~2017-08-07 19:12 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-28 12:40 Potential incorrect simplification Dibyendu Majumdar
2017-03-28 13:34 ` Luc Van Oostenryck
2017-03-28 13:58   ` Dibyendu Majumdar
2017-03-28 14:11     ` Luc Van Oostenryck
2017-03-28 14:19       ` Dibyendu Majumdar
2017-03-28 16:20         ` Linus Torvalds
2017-03-28 17:00           ` Luc Van Oostenryck
2017-03-28 18:02             ` Linus Torvalds
2017-03-28 20:27               ` Luc Van Oostenryck
2017-03-28 21:57                 ` Linus Torvalds
2017-03-28 22:28                   ` Luc Van Oostenryck
2017-03-28 22:22           ` Dibyendu Majumdar
2017-08-06 12:46           ` Christopher Li
2017-08-06 14:00             ` Luc Van Oostenryck
2017-08-06 14:24               ` Christopher Li
2017-08-06 14:54                 ` Christopher Li
2017-08-06 15:07                 ` Luc Van Oostenryck
2017-08-06 15:51                   ` Christopher Li
2017-08-06 16:51                     ` Luc Van Oostenryck
2017-08-06 18:35                       ` Christopher Li
2017-08-06 19:51                         ` Dibyendu Majumdar
2017-08-06 20:08                           ` Luc Van Oostenryck
2017-08-06 19:52                         ` Luc Van Oostenryck
2017-08-06 23:34                           ` Christopher Li
2017-08-07  0:31                             ` Luc Van Oostenryck
2017-08-07  0:38                               ` Christopher Li
2017-08-06 15:52                 ` Dibyendu Majumdar
2017-08-06 16:56                   ` Luc Van Oostenryck
2017-08-06 17:04                     ` Dibyendu Majumdar
2017-08-06 17:45                       ` Luc Van Oostenryck
2017-08-06 17:58                         ` Dibyendu Majumdar
2017-08-06 18:15                           ` Luc Van Oostenryck
2017-08-06 18:18                             ` Dibyendu Majumdar
2017-08-06 18:31                               ` Luc Van Oostenryck
2017-08-07 19:11                   ` [PATCH v2 0/8] fix loading of partially defined bitfield Luc Van Oostenryck
2017-08-07 19:11                     ` [PATCH v2 1/8] Remove single-store shortcut Luc Van Oostenryck
2017-08-07 21:42                       ` Linus Torvalds
2017-08-10  0:29                         ` Christopher Li
2017-08-10  0:41                           ` Luc Van Oostenryck
2017-08-10  0:53                             ` Christopher Li
2017-08-10 11:01                       ` Christopher Li
2017-08-10 12:26                         ` Luc Van Oostenryck
2017-08-10 13:25                           ` Christopher Li
2017-08-07 19:11                     ` [PATCH v2 2/8] new helper: def_opcode() Luc Van Oostenryck
2017-08-07 19:12                     ` [PATCH v2 3/8] reuse nbr_pseudo_users() Luc Van Oostenryck
2017-08-07 19:12                     ` [PATCH v2 4/8] change the masking when loading bitfields Luc Van Oostenryck
2017-08-07 19:12                     ` [PATCH v2 5/8] simplify ((A & M') | B ) & M when M' & M == 0 Luc Van Oostenryck
2017-08-07 19:12                     ` [PATCH v2 6/8] transform (A & M) >> S to (A >> S) & (M >> S) Luc Van Oostenryck
2017-08-08  0:22                       ` Christopher Li
2017-08-08  0:29                         ` Luc Van Oostenryck
2017-08-08  1:48                           ` Christopher Li
2017-08-08  1:00                         ` Linus Torvalds
2017-08-08  1:38                           ` Luc Van Oostenryck
2017-08-08  1:50                           ` Christopher Li
2017-08-07 19:12                     ` [PATCH v2 7/8] transform (A << S) >> S into A & (-1 " Luc Van Oostenryck
2017-08-07 21:54                       ` Linus Torvalds
2017-08-07 22:08                         ` Luc Van Oostenryck
2017-08-07 22:27                           ` Luc Van Oostenryck
2017-08-07 19:12                     ` Luc Van Oostenryck [this message]

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