Re: [PATCH] x86: LLVMLinux: Wrap -mno-80387 with cc-option

From: Behan Webster
Date: Tue Apr 22 2014 - 02:23:59 EST


On 04/21/14 23:05, Ingo Molnar wrote:
* behanw@xxxxxxxxxxxxxxxxxx <behanw@xxxxxxxxxxxxxxxxxx> wrote:

From: Behan Webster <behanw@xxxxxxxxxxxxxxxxxx>

Wrap -mno-80387 gcc options with cc-option so they don't break clang.

Signed-off-by: Behan Webster <behanw@xxxxxxxxxxxxxxxxxx>
---
arch/x86/Makefile | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index d1b7c37..ce6ad7e 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -83,7 +83,9 @@ else
KBUILD_CFLAGS += -m64
# Don't autogenerate traditional x87, MMX or SSE instructions
- KBUILD_CFLAGS += -mno-mmx -mno-sse -mno-80387 -mno-fp-ret-in-387
+ KBUILD_CFLAGS += -mno-mmx -mno-sse
+ KBUILD_CFLAGS += $(call cc-option,-mno-80387)
+ KBUILD_CFLAGS += $(call cc-option,-mno-fp-ret-in-387)
Is there a clang equivalent option that inhibits all things FPU opcode
generation by the compiler?
Not that I've found yet. Still investigating.

That's the general purpose of -no-80387.
Yes, I understand what this is trying to accomplish. At this point I'd just like this new code not to break the use of clang with v3.15.

I will submit another patch which adds similar functionality when compiled with clang once I have that answer.

Behan

--
Behan Webster
behanw@xxxxxxxxxxxxxxxxxx

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