On Tue, 17 Nov 2015, kbuild test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git test > head: e37d8480fbd6b9ad3665ac85a903098413ba67ae > commit: 71fa67f178c6c3c338d0b99644bce808f2f0965e [7/8] sparc/math-emu: Move sparc from math-emu-old to math-emu > config: sparc-defconfig (attached as .config) > reproduce: > wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross > chmod +x ~/bin/make.cross > git checkout 71fa67f178c6c3c338d0b99644bce808f2f0965e > # save the attached .config to linux build tree > make.cross ARCH=sparc > > All errors (new ones prefixed by >>): > > In file included from arch/sparc/math-emu/math_32.c:77:0: > >> include/math-emu/quad.h:72:1: error: unable to emulate 'TF' > typedef float TFtype __attribute__ ((mode (TF))); Is this with a compiler that defaults to -mlong-double-64 (which is, I think, now an unusual configuration on SPARC - it might arise for bootstrap compilers, but any normal distribution compiler should default to -mlong-double-128)? If so, the old code would have been quietly building with a union that contains the "wrong" long double type, when using such a compiler. And actually I think that because of the particular subset of macros used, this would have worked; the long double member of the union wouldn't have been used in this code. My inclination would be to use CFLAGS_math_32.o = -mlong-double-128 CFLAGS_math_64.o = -mlong-double-128 in arch/sparc/math-emu/Makefile to fix this properly (the "unable to emulate" error is for modes that fail GCC's scalar_mode_supported_p hook, which by default allows the modes for all standard types, hence an error for -mlong-double-64 when TFmode isn't used by a standard type). Untested incremental patch follows. Signed-off-by: Joseph Myers <joseph@xxxxxxxxxxxxxxxx> --- diff --git a/arch/sparc/math-emu/Makefile b/arch/sparc/math-emu/Makefile index 825dbee..6df8769 100644 --- a/arch/sparc/math-emu/Makefile +++ b/arch/sparc/math-emu/Makefile @@ -5,4 +5,9 @@ # suppress all warnings - as math.c produces a lot! ccflags-y := -w +# Emulation of quad instructions requires -mlong-double-128 for +# __attribute__ ((mode (TF))) to be accepted. +CFLAGS_math_32.o = -mlong-double-128 +CFLAGS_math_64.o = -mlong-double-128 + obj-y := math_$(BITS).o -- Joseph S. Myers joseph@xxxxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
