From: "Alex Bennée" <alex.bennee@linaro.org>
To: qemu-devel@nongnu.org
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
"Alex Bennée" <alex.bennee@linaro.org>,
"Aurelien Jarno" <aurelien@aurel32.net>
Subject: [PATCH v1 5/7] fpu/softfloat: avoid undefined behaviour when normalising empty sigs
Date: Fri, 27 Mar 2020 09:49:43 +0000 [thread overview]
Message-ID: <20200327094945.23768-6-alex.bennee@linaro.org> (raw)
In-Reply-To: <20200327094945.23768-1-alex.bennee@linaro.org>
The undefined behaviour checker pointed out that a shift of 64 would
lead to undefined behaviour.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
fpu/softfloat.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 301ce3b537b..444d35920dd 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -3834,9 +3834,14 @@ void normalizeFloatx80Subnormal(uint64_t aSig, int32_t *zExpPtr,
{
int8_t shiftCount;
- shiftCount = clz64(aSig);
- *zSigPtr = aSig<<shiftCount;
- *zExpPtr = 1 - shiftCount;
+ if (aSig) {
+ shiftCount = clz64(aSig);
+ *zSigPtr = aSig << shiftCount;
+ *zExpPtr = 1 - shiftCount;
+ } else {
+ *zSigPtr = 0;
+ *zExpPtr = 1 - 64;
+ }
}
/*----------------------------------------------------------------------------
--
2.20.1
next prev parent reply other threads:[~2020-03-27 9:53 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-27 9:49 [PATCH for 5.0 v1 0/7] A selection of sanitiser fixes Alex Bennée
2020-03-27 9:49 ` [PATCH v1 1/7] elf-ops: bail out if we have no function symbols Alex Bennée
2020-03-27 10:53 ` Philippe Mathieu-Daudé
2020-03-27 11:10 ` Philippe Mathieu-Daudé
2020-03-27 11:45 ` Peter Maydell
2020-03-27 22:09 ` Richard Henderson
2020-03-27 9:49 ` [PATCH v1 2/7] linux-user: protect fcntl64 with an #ifdef Alex Bennée
2020-03-27 10:40 ` Laurent Vivier
2020-03-27 22:10 ` Richard Henderson
2020-03-27 9:49 ` [PATCH v1 3/7] tests/tcg: remove extraneous pasting macros Alex Bennée
2020-03-27 10:54 ` Philippe Mathieu-Daudé
2020-03-27 22:11 ` Richard Henderson
2020-03-27 9:49 ` [PATCH v1 4/7] linux-user: more debug for init_guest_space Alex Bennée
2020-03-27 10:50 ` Laurent Vivier
2020-03-27 9:49 ` Alex Bennée [this message]
2020-03-27 10:09 ` [PATCH v1 5/7] fpu/softfloat: avoid undefined behaviour when normalising empty sigs Peter Maydell
2020-03-27 22:27 ` Richard Henderson
2020-03-27 22:33 ` Peter Maydell
2020-03-27 10:13 ` Aleksandar Markovic
2020-03-27 10:31 ` Alex Bennée
2020-03-27 9:49 ` [PATCH v1 6/7] target/xtensa: add FIXME for translation memory leak Alex Bennée
2020-03-27 9:49 ` [PATCH v1 7/7] gdbstub: fix compiler complaining Alex Bennée
2020-03-27 10:56 ` Philippe Mathieu-Daudé
2020-03-27 10:53 ` [PATCH for 5.0 v1 0/7] A selection of sanitiser fixes no-reply
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