On Thu, 15 Dec 2016, Aaron Sawdey wrote: > + emit_library_call_value (gen_rtx_SYMBOL_REF (Pmode, "strncmp"), > + target, LCT_NORMAL, GET_MODE (target), 3, > + force_reg (Pmode, XEXP (src1, 0)), Pmode, > + force_reg (Pmode, XEXP (src2, 0)), Pmode, > + len_rtx, GET_MODE (len_rtx));
Building glibc with GCC mainline for powerpc64le-linux-gnu (from my bot doing such builds and compilation parts of the testsuite for all GNU/Linux glibc ABIs daily), I'm seeing a failure of the elf/check-localplt test, "Extra PLT reference: libc.so: strncmp". Without having bisected, I suspect this patch of being a likely cause of that failure. glibc redirects internal calls to use hidden aliases such as __GI_strncmp to avoid them going through the PLT. By using gen_rtx_SYMBOL_REF there with a hardcoded function name "strncmp", this code looks like it would render a declaration of strncmp with asm ("__GI_strncmp") ineffective, generating a direct call to strncmp when glibc expects __GI_strncmp to be called instead. I don't know how readily this code can be made to respect asm renaming of strncmp. If it's hard to fix in GCC, I suppose glibc needs a powerpc version of symbol-hacks.h to handle this redirection. -- Joseph S. Myers jos...@codesourcery.com