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Because floatx80 has an explicit integer bit, this permits some odd encodings where the integer bit is not set correctly for the floating point value type. In In Intel terminology the categories are: exp == 0, int = 0, mantissa == 0 : zeroes exp == 0, int = 0, mantissa != 0 : denormals exp == 0, int = 1 : pseudo-denormals 0 < exp < 0x7fff, int = 0 : unnormals 0 < exp < 0x7fff, int = 1 : normals exp == 0x7fff, int = 0, mantissa == 0 : pseudo-infinities exp == 0x7fff, int = 1, mantissa == 0 : infinities exp == 0x7fff, int = 0, mantissa != 0 : pseudo-NaNs exp == 0x7fff, int = 1, mantissa == 0 : NaNs The usual IEEE cases of zero, denormal, normal, inf and NaN are always valid. x87 permits as input also pseudo-denormals. m68k permits all those and also pseudo-infinities, pseudo-NaNs and unnormals. Currently we have an ifdef in floatx80_invalid_encoding() to select the x86 vs m68k behaviour. Add new floatx80_behaviour flags to select whether pseudo-NaN and unnormal are valid, and use these (plus the existing pseudo_inf_valid flag) to decide whether these encodings are invalid at runtime. We leave pseudo-denormals as always-valid, since both x86 and m68k accept them. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Message-id: 20250224111524.1101196-8-peter.maydell@linaro.org Message-id: 20250217125055.160887-6-peter.maydell@linaro.org |
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| hexagon | ||
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| i386 | ||
| loongarch | ||
| m68k | ||
| microblaze | ||
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| openrisc | ||
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| tricore | ||
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| Kconfig | ||
| meson.build | ||