as: MIPS FP ABI History
9.26.9.1 History of FP ABIs
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The MIPS ABIs support a variety of different floating-point extensions
where calling-convention and register sizes vary for floating-point
data. The extensions exist to support a wide variety of optional
architecture features. The resulting ABI variants are generally
incompatible with each other and must be tracked carefully.
Traditionally the use of an explicit '.gnu_attribute 4, N' directive
is used to indicate which ABI is in use by a specific module. It was
then left to the user to ensure that command-line options and the
selected ABI were compatible with some potential for inconsistencies.
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as: MIPS FP ABIs
as: MIPS FP ABI Variants