From d7acb92fea932ad2e7846480aeacddc2c03c8485 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Wed, 13 Oct 2010 16:00:29 -0700 Subject: x86-64, asm: If the assembler supports fxsave64, use it Kbuild allows for us to probe for the existence of specific constructs in the assembler, use them to find out if we can use fxsave64 and permit the compiler to generate better code. Signed-off-by: H. Peter Anvin --- arch/x86/Makefile | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'arch/x86/Makefile') diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 8aa1b59b9074..40668a96ca0c 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -96,8 +96,12 @@ cfi := $(call as-instr,.cfi_startproc\n.cfi_rel_offset $(sp-y)$(comma)0\n.cfi_en # is .cfi_signal_frame supported too? cfi-sigframe := $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1) cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTIONS=1) -KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) -KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) + +# does binutils support specific instructions? +asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1) + +KBUILD_AFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) +KBUILD_CFLAGS += $(cfi) $(cfi-sigframe) $(cfi-sections) $(asinstr) LDFLAGS := -m elf_$(UTS_MACHINE) -- cgit v1.2.3