*参照元 [#zf6b8a4e] #backlinks *説明 [#k0808e19] -パス: [[linux-2.6.33/]] -FIXME: これは何? --説明 **引数 [#g6808a3a] - -- **返り値 [#n642e2c1] - -- **参考 [#vd136d02] *実装 [#abdcc068] /* * This macro obfuscates arithmetic on a variable address so that gcc * shouldn't recognize the original var, and make assumptions about it. * * This is needed because the C standard makes it undefined to do * pointer arithmetic on "objects" outside their boundaries and the * gcc optimizers assume this is the case. In particular they * assume such arithmetic does not wrap. * * A miscompilation has been observed because of this on PPC. * To work around it we hide the relationship of the pointer and the object * using this macro. * * Versions of the ppc64 compiler before 4.1 had a bug where use of * RELOC_HIDE could trash r30. The bug can be worked around by changing * the inline assembly constraint from =g to =r, in this particular * case either is valid. */ #define RELOC_HIDE(ptr, off) \ ({ unsigned long __ptr; \ __asm__ ("" : "=r"(__ptr) : "0"(ptr)); \ (typeof(ptr)) (__ptr + (off)); }) - -- *コメント [#fc9494fd]