From d1eb8f2acba579830cf3798c3c15ce51be852c56 Mon Sep 17 00:00:00 2001 From: Andrew Dutcher Date: Tue, 16 Aug 2016 17:14:55 -0700 Subject: 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 Reviewed-by: Peter Maydell 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 --- include/fpu/softfloat.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'include/fpu/softfloat.h') 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) -- cgit v1.1