On Wed, Sep 9, 2015 at 2:54 PM, Peter Zijlstra <pet...@infradead.org> wrote: > On Wed, Sep 09, 2015 at 12:05:50PM +0200, Sedat Dilek wrote: >> I can boot into a CLANG v3.7 compiled Linux-kernel when lib/bitmap is >> compiled with GCC (here: v4.9). >> >> CONFIG_OPTIMIZE_INLINING has no effect on this. >> >> Attached are the single llvmlinux patch for AMD64 (x86_64), my >> kernel-config and 2 objdumps with bitmap.o file alltogether. > > I suggest you go tell the LLVM people their compiler is broken.
It looks like an inline-optimization bug in CLANG when the compiler's optimization-level is higher than -O2. Level -O0 and -O1 are OK - I can boot in such Linux-kernel v4.2. With Level -Oz when CONFIG_CC_OPTIMIZE_FOR_SIZE=y (equivalent to GCC's -Os) the objdump looked sane but I cannot boot on bare metal. Re-compiling lib/bitmap with -O0 or -O1 is fine again. - Sedat - [1] http://lists.linuxfoundation.org/pipermail/llvmlinux/2015-September/001355.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
