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[5/5] x86 kbuild: LLVMLinux: More cc-options added for clang

Message ID 1393376923-21892-6-git-send-email-behanw@converseincode.com (mailing list archive)
State New, archived
Headers show

Commit Message

Behan Webster Feb. 26, 2014, 1:08 a.m. UTC 
From: Jan-Simon Möller <dl9pf@gmx.de>

Protect more options for x86 with cc-option so that we don't get errors when
using clang instead of gcc.  Add more or different options when using clang as
well. Also need to enforce that SSE is off for clang and the stack is 8-byte
aligned.

Signed-off-by: Jan-Simon Möller <dl9pf@gmx.de>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Signed-off-by: Mark Charlebois <charlebm@gmail.com>
---
 arch/x86/Makefile | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Comments

H. Peter Anvin Feb. 26, 2014, 1:32 a.m. UTC | #1 
On 02/25/2014 05:08 PM, behanw@converseincode.com wrote:
>  
> +# enforce no-sse for clang
> +ifneq ($(COMPILER),clang)
> +        KBUILD_CFLAGS += $(call cc-option,-mno-sse)
> +        KBUILD_CFLAGS += $(call cc-option,-mpreferred-stack-boundary=3)
> +endif
> +

I'm *very* confused.  You're doing ifneq here but you're talking about
it as if you are *adding* them for Clang, also these options are already
added elsewhere (lines 57, 64, 86, 89) so why add them here?

	-hpa

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Behan Webster Feb. 26, 2014, 1:44 a.m. UTC | #2 
On 02/25/14 17:32, H. Peter Anvin wrote:
> On 02/25/2014 05:08 PM, behanw@converseincode.com wrote:
>>   
>> +# enforce no-sse for clang
>> +ifneq ($(COMPILER),clang)
>> +        KBUILD_CFLAGS += $(call cc-option,-mno-sse)
>> +        KBUILD_CFLAGS += $(call cc-option,-mpreferred-stack-boundary=3)
>> +endif
>> +
> I'm *very* confused.  You're doing ifneq here but you're talking about
> it as if you are *adding* them for Clang, also these options are already
> added elsewhere (lines 57, 64, 86, 89) so why add them here?
Because when David Woodhouse's recent .code16 changes made it upstream 
(which invalidated most of our original patch) it seems I didn't remove 
this properly from our patch as well. :)

Thanks David for your patches. Thanks Peter for your sharp eyes!

Another example of why reviewing code on the mailing list works so well.

I will fix and resend.

Behan
diff mbox

Patch

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index eeda43a..852d8f0 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -108,7 +108,7 @@  else
 
         # this works around some issues with generating unwind tables in older gccs
         # newer gccs do it by default
-        KBUILD_CFLAGS += -maccumulate-outgoing-args
+        KBUILD_CFLAGS += $(call cc-option,-maccumulate-outgoing-args)
 endif
 
 # Make sure compiler does not have buggy stack-protector support.
@@ -144,6 +144,12 @@  endif
 sp-$(CONFIG_X86_32) := esp
 sp-$(CONFIG_X86_64) := rsp
 
+# enforce no-sse for clang
+ifneq ($(COMPILER),clang)
+        KBUILD_CFLAGS += $(call cc-option,-mno-sse)
+        KBUILD_CFLAGS += $(call cc-option,-mpreferred-stack-boundary=3)
+endif
+
 # do binutils support CFI?
 cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_endproc,-DCONFIG_AS_CFI=1)
 # is .cfi_signal_frame supported too?