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authorH. Peter Anvin <hpa@linux.intel.com>2010-10-13 16:00:29 -0700
committerH. Peter Anvin <hpa@linux.intel.com>2010-10-13 16:00:29 -0700
commitd7acb92fea932ad2e7846480aeacddc2c03c8485 (patch)
tree21675108634aff8885cb881a476acf7146191b87 /arch/x86/Makefile
parent7fe977dab356fbd7e86aa10bf83891761107c57c (diff)
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 <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/Makefile')
-rw-r--r--arch/x86/Makefile8
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 8aa1b59b907..40668a96ca0 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)