Better support for linux kernel #62
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Add a macro for dividing 64bit numbers. With 32bit linux targets, GCC generates a call to __udivdi3 when dividing 64bit integers, even when compiling in freestanding mode. However, the __udivdi3 implementation resides in libgcc which is not linked-in when building kernel code. Besides, the Linux kernel voluntarily doesn't implement __udivdi3 to force developers to use the do_div macro instead [1]. [1] https://lwn.net/Articles/456689/
Fallback to custom defined types when __*_TYPE__ macros are not defined on GCC. Old versions of GCC such as version 4.4.7 and prior do not define the __*_TYPE__ macros, so provide custom type definition when building without libc headers [1]. Also add custom definition for ZYAN_*_MAX and ZYAN_*_MIN values as __*_MAX__ macros are also missing for the same reason [2]. [1] https://godbolt.org/z/j5Yhs48z9 [2] https://godbolt.org/z/1TvjTd5Ga
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Thanks for your PR! Will have a detailed look tomorrow. cc @athre0z |
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Sorry for the delay. LGTM! Thanks again. |
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Hi,
These two commits improve support for building Zydis for the linux kernel in a couple of corner cases:
The first commit introduces the ZYAN_DIV64 macro to fix a failure when linking Zydis on a 32bit linux kernel. The Zydis changes will be submitted in a separate PR.
The second PR adds support for building Zydis in NO_LIBC mode with old versions of GCC.
Thanks,