From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org, alex.bennee@linaro.org
Subject: [PATCH] softfloat: Fix BAD_SHIFT from normalizeFloatx80Subnormal
Date: Fri, 27 Mar 2020 16:20:42 -0700 [thread overview]
Message-ID: <20200327232042.10008-1-richard.henderson@linaro.org> (raw)
All other calls to normalize*Subnormal detect zero input before
the call -- this is the only outlier. This case can happen with
+0.0 + +0.0 = +0.0 or -0.0 + -0.0 = -0.0, so return a zero of
the correct sign.
Reported-by: Coverity (CID 1421991)
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
fpu/softfloat.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 301ce3b537..ae6ba71854 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -5856,6 +5856,9 @@ static floatx80 addFloatx80Sigs(floatx80 a, floatx80 b, flag zSign,
zSig1 = 0;
zSig0 = aSig + bSig;
if ( aExp == 0 ) {
+ if (zSig0 == 0) {
+ return packFloatx80(zSign, 0, 0);
+ }
normalizeFloatx80Subnormal( zSig0, &zExp, &zSig0 );
goto roundAndPack;
}
--
2.20.1
next reply other threads:[~2020-03-27 23:21 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-27 23:20 Richard Henderson [this message]
2020-03-30 11:32 ` [PATCH] softfloat: Fix BAD_SHIFT from normalizeFloatx80Subnormal Alex Bennée
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