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| author | Andrew Dutcher <andrew@andrewdutcher.com> | 2016-08-16 17:14:55 -0700 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2016-09-15 12:43:18 +0100 |
| commit | d1eb8f2acba579830cf3798c3c15ce51be852c56 (patch) | |
| tree | f9ffe185bcbe8746a42a37927861878c525d982a /include/fpu | |
| parent | 9e8204b1de9c4d09c0ec8f1c004a2e11346eb116 (diff) | |
| download | qemu-d1eb8f2acba579830cf3798c3c15ce51be852c56.zip qemu-d1eb8f2acba579830cf3798c3c15ce51be852c56.tar.gz qemu-d1eb8f2acba579830cf3798c3c15ce51be852c56.tar.bz2 | |
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')
| -rw-r--r-- | include/fpu/softfloat.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h index 1bde349..14f8383 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) |