mk: rework cpu flags detection

For cases where the compilation microarchitecture is explicitly given, we
extract the cpu-flags to use from the compiler rather than hard-coding. This
means that we will only ever use instruction sets supported by the compiler,
rather than having a case where the uarch and the Intel DPDK both support a
given instruction-set, but the compiler does not.
In the case where 'native' uarch support is requested, the same mechanism is
also used to detect the instruction-sets supported

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Signed-off-by: David Marchand <david.marchand@6wind.com>

mk/machine/atm/rte.vars.mk

@@ -56,4 +56,3 @@
 # CPU_ASFLAGS =
 
 MACHINE_CFLAGS = -march=atom
-CPUFLAGS = SSE SSE2 SSE3 SSSE3

mk/machine/default/rte.vars.mk

@@ -56,4 +56,3 @@
 # CPU_ASFLAGS =
 
 MACHINE_CFLAGS += -march=core2
-CPUFLAGS = SSE SSE2 SSE3

mk/machine/ivb/rte.vars.mk

@@ -56,4 +56,3 @@
 # CPU_ASFLAGS =
 
 MACHINE_CFLAGS = -march=core-avx-i
-CPUFLAGS = SSE SSE2 SSE3 SSSE3 SSE4_1 SSE4_2 AES PCLMULQDQ AVX RDRAND FSGSBASE F16C

mk/machine/native/rte.vars.mk

@@ -56,54 +56,3 @@
 # CPU_ASFLAGS =
 
 MACHINE_CFLAGS = -march=native
-AUTO_CPUFLAGS = $(shell grep -m 1 flags /proc/cpuinfo)
-
-# adding flags to CPUFLAGS
-
-ifneq ($(filter $(AUTO_CPUFLAGS),sse),)
-CPUFLAGS += SSE
-endif
-
-ifneq ($(filter $(AUTO_CPUFLAGS),sse2),)
-CPUFLAGS += SSE2
-endif
-
-ifneq ($(filter $(AUTO_CPUFLAGS),sse3),)
-CPUFLAGS += SSE3
-endif
-
-ifneq ($(filter $(AUTO_CPUFLAGS),ssse3),)
-CPUFLAGS += SSSE3
-endif
-
-ifneq ($(filter $(AUTO_CPUFLAGS),sse4_1),)
-CPUFLAGS += SSE4_1
-endif
-
-ifneq ($(filter $(AUTO_CPUFLAGS),sse4_2),)
-CPUFLAGS += SSE4_2
-endif
-
-ifneq ($(filter $(AUTO_CPUFLAGS),aes),)
-CPUFLAGS += AES
-endif
-
-ifneq ($(filter $(AUTO_CPUFLAGS),pclmulqdq),)
-CPUFLAGS += PCLMULQDQ
-endif
-
-ifneq ($(filter $(AUTO_CPUFLAGS),avx),)
-CPUFLAGS += AVX
-endif
-
-ifneq ($(filter $(AUTO_CPUFLAGS),rdrnd),)
-CPUFLAGS += RDRAND
-endif
-
-ifneq ($(filter $(AUTO_CPUFLAGS),fsgsbase),)
-CPUFLAGS += FSGSBASE
-endif
-
-ifneq ($(filter $(AUTO_CPUFLAGS),f16c),)
-CPUFLAGS += F16C
-endif

mk/machine/nhm/rte.vars.mk

@@ -56,4 +56,3 @@
 # CPU_ASFLAGS =
 
 MACHINE_CFLAGS = -march=corei7
-CPUFLAGS = SSE SSE2 SSE3 SSSE3 SSE4_1 SSE4_2

mk/machine/snb/rte.vars.mk

@@ -56,4 +56,3 @@
 # CPU_ASFLAGS =
 
 MACHINE_CFLAGS = -march=corei7-avx
-CPUFLAGS = SSE SSE2 SSE3 SSSE3 SSE4_1 SSE4_2 AES PCLMULQDQ AVX

mk/machine/wsm/rte.vars.mk

@@ -56,4 +56,3 @@
 # CPU_ASFLAGS =
 
 MACHINE_CFLAGS = -march=corei7 -maes -mpclmul
-CPUFLAGS = SSE SSE2 SSE3 SSSE3 SSE4_1 SSE4_2 AES PCLMULQDQ

mk/rte.cpuflags.mk

@@ -0,0 +1,100 @@
+#   BSD LICENSE
+# 
+#   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+#   All rights reserved.
+# 
+#   Redistribution and use in source and binary forms, with or without
+#   modification, are permitted provided that the following conditions
+#   are met:
+# 
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in
+#       the documentation and/or other materials provided with the
+#       distribution.
+#     * Neither the name of Intel Corporation nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+# 
+#   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+#   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+#   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+#   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+#   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+#   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+#   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+#   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+#   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+#   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+#   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# this makefile is called from the generic rte.vars.mk and is
+# used to set the RTE_CPUFLAG_* environment variables giving details
+# of what instruction sets the target cpu supports.
+
+AUTO_CPUFLAGS := $(shell $(CC) $(MACHINE_CFLAGS) -dM -E - < /dev/null)
+
+# adding flags to CPUFLAGS
+
+ifneq ($(filter $(AUTO_CPUFLAGS),__SSE__),)
+CPUFLAGS += SSE
+endif
+
+ifneq ($(filter $(AUTO_CPUFLAGS),__SSE2__),)
+CPUFLAGS += SSE2
+endif
+
+ifneq ($(filter $(AUTO_CPUFLAGS),__SSE3__),)
+CPUFLAGS += SSE3
+endif
+
+ifneq ($(filter $(AUTO_CPUFLAGS),__SSSE3__),)
+CPUFLAGS += SSSE3
+endif
+
+ifneq ($(filter $(AUTO_CPUFLAGS),__SSE4_1__),)
+CPUFLAGS += SSE4_1
+endif
+
+ifneq ($(filter $(AUTO_CPUFLAGS),__SSE4_2__),)
+CPUFLAGS += SSE4_2
+endif
+
+ifneq ($(filter $(AUTO_CPUFLAGS),__AES__),)
+CPUFLAGS += AES
+endif
+
+ifneq ($(filter $(AUTO_CPUFLAGS),__PCLMUL__),)
+CPUFLAGS += PCLMULQDQ
+endif
+
+ifneq ($(filter $(AUTO_CPUFLAGS),__AVX__),)
+CPUFLAGS += AVX
+endif
+
+ifneq ($(filter $(AUTO_CPUFLAGS),__RDRND__),)
+CPUFLAGS += RDRAND
+endif
+
+ifneq ($(filter $(AUTO_CPUFLAGS),__FSGSBASE__),)
+CPUFLAGS += FSGSBASE
+endif
+
+ifneq ($(filter $(AUTO_CPUFLAGS),__F16C__),)
+CPUFLAGS += F16C
+endif
+
+ifneq ($(filter $(AUTO_CPUFLAGS),__AVX2__),)
+CPUFLAGS += AVX2
+endif
+
+MACHINE_CFLAGS += $(addprefix -DRTE_MACHINE_CPUFLAG_,$(CPUFLAGS))
+
+# To strip whitespace
+comma:= ,
+empty:=
+space:= $(empty) $(empty)
+CPUFLAGSTMP1 := $(addprefix RTE_CPUFLAG_,$(CPUFLAGS))
+CPUFLAGSTMP2 := $(subst $(space),$(comma),$(CPUFLAGSTMP1))
+MACHINE_CFLAGS += -DRTE_COMPILE_TIME_CPUFLAGS=$(CPUFLAGSTMP2)

mk/target/generic/rte.vars.mk

@@ -102,6 +102,10 @@ include $(RTE_SDK)/mk/exec-env/$(RTE_EXEC_ENV)/rte.vars.mk
 # provided by Kbuild framework.
 ifeq ($(KERNELRELEASE),)
 
+# now that the environment is mostly set up, including the machine type we will
+# be passing to the compiler, set up the specific CPU flags based on that info.
+include $(RTE_SDK)/mk/rte.cpuflags.mk
+
 # merge all CFLAGS
 CFLAGS := $(CPU_CFLAGS) $(EXECENV_CFLAGS) $(TOOLCHAIN_CFLAGS) $(MACHINE_CFLAGS)
 CFLAGS += $(TARGET_CFLAGS)

mk/toolchain/gcc/rte.toolchain-compat.mk

@@ -86,12 +86,4 @@ else
 		MACHINE_CFLAGS := $(filter-out -march% -mtune% -msse%,$(MACHINE_CFLAGS))
 	endif
 endif
-MACHINE_CFLAGS += $(addprefix -DRTE_MACHINE_CPUFLAG_,$(CPUFLAGS))
 
-# To strip whitespace
-comma:= ,
-empty:=
-space:= $(empty) $(empty)
-CPUFLAGSTMP1 := $(addprefix RTE_CPUFLAG_,$(CPUFLAGS))
-CPUFLAGSTMP2 := $(subst $(space),$(comma),$(CPUFLAGSTMP1))
-MACHINE_CFLAGS += -DRTE_COMPILE_TIME_CPUFLAGS=$(CPUFLAGSTMP2)

mk/toolchain/icc/rte.toolchain-compat.mk

@@ -71,12 +71,4 @@ else
 		MACHINE_CFLAGS := $(patsubst -march=%,-xSSE3,$(MACHINE_CFLAGS))
 	endif
 endif
-MACHINE_CFLAGS += $(addprefix -DRTE_MACHINE_CPUFLAG_,$(CPUFLAGS))
 
-# To strip whitespace
-comma:= ,
-empty:=
-space:= $(empty) $(empty)
-CPUFLAGSTMP1 := $(addprefix RTE_CPUFLAG_,$(CPUFLAGS))
-CPUFLAGSTMP2 := $(subst $(space),$(comma),$(CPUFLAGSTMP1))
-MACHINE_CFLAGS += -DRTE_COMPILE_TIME_CPUFLAGS=$(CPUFLAGSTMP2)