path: root/include/fpu
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authorAndrew Dutcher <andrew@andrewdutcher.com>2016-08-16 17:14:55 -0700
committerPeter Maydell <peter.maydell@linaro.org>2016-09-15 12:43:18 +0100
commitd1eb8f2acba579830cf3798c3c15ce51be852c56 (patch)
treef9ffe185bcbe8746a42a37927861878c525d982a /include/fpu
parent9e8204b1de9c4d09c0ec8f1c004a2e11346eb116 (diff)
fpu: add mechanism to check for invalid long double formats
All operations that take a floatx80 as an operand need to have their inputs checked for malformed encodings. In all of these cases, use the function floatx80_invalid_encoding to perform the check. If an invalid operand is found, raise an invalid operation exception, and then return either NaN (for fp-typed results) or the integer indefinite value (the minimum representable signed integer value, for int-typed results). For the non-quiet comparison operations, this touches adjacent code in order to pass style checks. Signed-off-by: Andrew Dutcher <andrew@andrewdutcher.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1471392895-17324-1-git-send-email-andrew@andrewdutcher.com [PMM: changed "1 << 63" to "1ULL << 63" to fix compile errors] Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'include/fpu')
1 files changed, 15 insertions, 0 deletions
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 1bde349b74..14f8383686 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -658,6 +658,21 @@ static inline int floatx80_is_any_nan(floatx80 a)
return ((a.high & 0x7fff) == 0x7fff) && (a.low<<1);
+| Return whether the given value is an invalid floatx80 encoding.
+| Invalid floatx80 encodings arise when the integer bit is not set, but
+| the exponent is not zero. The only times the integer bit is permitted to
+| be zero is in subnormal numbers and the value zero.
+| This includes what the Intel software developer's manual calls pseudo-NaNs,
+| pseudo-infinities and un-normal numbers. It does not include
+| pseudo-denormals, which must still be correctly handled as inputs even
+| if they are never generated as outputs.
+static inline bool floatx80_invalid_encoding(floatx80 a)
+ return (a.low & (1ULL << 63)) == 0 && (a.high & 0x7FFF) != 0;
#define floatx80_zero make_floatx80(0x0000, 0x0000000000000000LL)
#define floatx80_one make_floatx80(0x3fff, 0x8000000000000000LL)
#define floatx80_ln2 make_floatx80(0x3ffe, 0xb17217f7d1cf79acLL)