Expose va_arg and va_start#84
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idk if this meets the GCC standards but for us it should do (for now)
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| static tree | ||
| jit_langhook_type_promotes_to (tree type) | ||
| { | ||
| /* The "default argument promotions" */ | ||
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| /* float is promoted to double. */ | ||
| if (TYPE_MAIN_VARIANT (type) == float_type_node) | ||
| return double_type_node; | ||
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| /* integers smaller than int are promoted to int. */ | ||
| if (INTEGRAL_TYPE_P (type) | ||
| && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)) | ||
| return integer_type_node; | ||
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| return type; | ||
| } |
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c-variadic arguments are subject to the "default argument promotions", so this hook ends up getting called when we try to compile a c-variadic call.
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I happen to know that _Complex is not subject to these rules, and I think f16 is not really a C type and this rule would also not apply here.
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The bits we need to hook up
va_argandva_startin the GCC backend. I got this to work onx86_64, I've tried to not bake in assumptions about other platforms (e.g. the layout ofVaList), but this code is pretty dense.I'll leave some comments on the non-boilerplate bits.