Re: [PATCH] powerpc: xor_vmx: Add '-mhard-float' to CFLAGS

From
Nathan Chancellor <nathan@kernel.org>
Date
2024-03-05 22:43:18
Also in
linux-patches, llvm, stable
Reply to
Nathan Chancellor, 2024-01-27
Ping? We have been applying this in our CI since it was sent, it would
be nice to have this upstream soon so it can start filtering through the
stable trees.

On Sat, Jan 27, 2024 at 11:07:43AM -0700, Nathan Chancellor wrote:
quoted hunk ↗ jump to hunk
arch/powerpc/lib/xor_vmx.o is built with '-msoft-float' (from the main
powerpc Makefile) and '-maltivec' (from its CFLAGS), which causes an
error when building with clang after a recent change in main:

  error: option '-msoft-float' cannot be specified with '-maltivec'
  make[6]: *** [scripts/Makefile.build:243: arch/powerpc/lib/xor_vmx.o] Error 1

Explicitly add '-mhard-float' before '-maltivec' in xor_vmx.o's CFLAGS
to override the previous inclusion of '-msoft-float' (as the last option
wins), which matches how other areas of the kernel use '-maltivec', such
as AMDGPU.

Cc: <redacted>
Closes: https://github.com/ClangBuiltLinux/linux/issues/1986
Link: https://github.com/llvm/llvm-project/commit/4792f912b232141ecba4cbae538873be3c28556c
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 arch/powerpc/lib/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 6eac63e79a89..0ab65eeb93ee 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -76,7 +76,7 @@ obj-$(CONFIG_PPC_LIB_RHEAP) += rheap.o
 obj-$(CONFIG_FTR_FIXUP_SELFTEST) += feature-fixups-test.o
 
 obj-$(CONFIG_ALTIVEC)	+= xor_vmx.o xor_vmx_glue.o
-CFLAGS_xor_vmx.o += -maltivec $(call cc-option,-mabi=altivec)
+CFLAGS_xor_vmx.o += -mhard-float -maltivec $(call cc-option,-mabi=altivec)
 # Enable <altivec.h>
 CFLAGS_xor_vmx.o += -isystem $(shell $(CC) -print-file-name=include)
 
---
base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d
change-id: 20240127-ppc-xor_vmx-drop-msoft-float-ad68b437f86c

Best regards,
-- 
Nathan Chancellor [off-list ref]
Thread (5 messages) 5 messages, 3 authors, last reply 2024-03-13
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