Re: [PATCH] raid6/ppc: Fix build for clang
From: Nick Desaulniers <hidden>
Date: 2018-10-31 19:55:11
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On Tue, Oct 30, 2018 at 8:28 PM Joel Stanley [off-list ref] wrote:
We cannot build these files with clang as it does not allow altivec instructions in assembly when -msoft-float is passed. Jinsong Ji [off-list ref] wrote:quoted
We currently disable Altivec/VSX support when enabling soft-float. So any usage of vector builtins will break. Enable Altivec/VSX with soft-float may need quite some clean up work, so I guess this is currently a limitation. Removing -msoft-float will make it work (and we are lucky that no floating point instructions will be generated as well).This is a workaround until the issue is resolved in clang. Link: https://bugs.llvm.org/show_bug.cgi?id=31177 Link: https://github.com/ClangBuiltLinux/linux/issues/239 Signed-off-by: Joel Stanley <joel@jms.id.au>
Hopefully we can have this fixed up soon. I'll try to see who works on Clang+PPC here and see if they can help move that bug along. Thanks for the patch!
quoted hunk ↗ jump to hunk
--- lib/raid6/Makefile | 15 +++++++++++++++ 1 file changed, 15 insertions(+)diff --git a/lib/raid6/Makefile b/lib/raid6/Makefile index 2f8b61dfd9b0..3a844e6fd01c 100644 --- a/lib/raid6/Makefile +++ b/lib/raid6/Makefile@@ -18,6 +18,21 @@ quiet_cmd_unroll = UNROLL $@ ifeq ($(CONFIG_ALTIVEC),y) altivec_flags := -maltivec $(call cc-option,-mabi=altivec) + +ifdef CONFIG_CC_IS_CLANG
Note that the top level makefile detects clang via: ifeq ($(cc-name),clang) Does that not work here? I'd prefer to keep compiler detection in Makefiles consistent, if it works?
+# clang ppc port does not yet support -maltifec when -msoft-float is +# enabled. A future release of clang will resolve this +# https://bugs.llvm.org/show_bug.cgi?id=31177 +CFLAGS_REMOVE_altivec1.o += -msoft-float +CFLAGS_REMOVE_altivec2.o += -msoft-float +CFLAGS_REMOVE_altivec4.o += -msoft-float +CFLAGS_REMOVE_altivec8.o += -msoft-float +CFLAGS_REMOVE_altivec8.o += -msoft-float +CFLAGS_REMOVE_vpermxor1.o += -msoft-float +CFLAGS_REMOVE_vpermxor2.o += -msoft-float +CFLAGS_REMOVE_vpermxor4.o += -msoft-float +CFLAGS_REMOVE_vpermxor8.o += -msoft-float +endif endif # The GCC option -ffreestanding is required in order to compile code containing -- 2.19.1
-- Thanks, ~Nick Desaulniers