[PATCH] x86: set fpmath to 387 to avoid gcc warnings

From: Dragos Tatulea
Date: Wed Aug 08 2012 - 02:25:50 EST


If gcc has a different default fpmath set (ex: sse),
many unuseful warnings will be spewed.

This can affect out of tree modules that compile with
-Werror (ex: systemtap stp scripts).

Be paranoid and add -msoft-float as well to try to
get an error if FP instructions are generated at all.

Change-Id: If9271d7aea7371f394ede0bc5e3ed1383cdb0e1a
Signed-off-by: Dragos Tatulea <dragos.tatulea@xxxxxxxxx>
---
arch/x86/Makefile | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index b1c611e..b771d0b 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -130,6 +130,7 @@ KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
# prevent gcc from generating any FP code by mistake
KBUILD_CFLAGS += $(call cc-option,-mno-sse -mno-mmx -mno-sse2 -mno-3dnow,)
KBUILD_CFLAGS += $(call cc-option,-mno-avx,)
+KBUILD_CFLAGS += $(call cc-option,-mfpmath=387 -msoft-float,)

KBUILD_CFLAGS += $(mflags-y)
KBUILD_AFLAGS += $(mflags-y)
--
1.7.9.5

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