[PATCH] build: disable compiler AVX512F support

From: Yongseok Koh <yskoh@mellanox.com>
To: Thomas Monjalon <thomas@monjalon.net>,
	"bruce.richardson@intel.com" <bruce.richardson@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
	Shahaf Shuler <shahafs@mellanox.com>,
	Yongseok Koh <yskoh@mellanox.com>,
	"stable@dpdk.org" <stable@dpdk.org>
Subject: [PATCH] build: disable compiler AVX512F support
Date: Tue, 23 Oct 2018 21:23:28 +0000	[thread overview]
Message-ID: <20181023212318.43082-1-yskoh@mellanox.com> (raw)

This is a workaround to prevent a crash, which might be caused by
optimization of newer gcc (7.3.0) on Intel Skylake.

Bugzilla ID: 97

Cc: stable@dpdk.org

Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
---
 config/x86/meson.build | 5 +++++
 mk/rte.cpuflags.mk     | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/config/x86/meson.build b/config/x86/meson.build
index 33efb5e547..e10ba872ac 100644
--- a/config/x86/meson.build
+++ b/config/x86/meson.build
@@ -47,6 +47,11 @@ endif
 if cc.get_define('__AVX512F__', args: march_opt) != ''
 	dpdk_conf.set('RTE_MACHINE_CPUFLAG_AVX512F', 1)
 	compile_time_cpuflags += ['RTE_CPUFLAG_AVX512F']
+else
+# disable compiler's AVX512F support as a workaround for Bug 97
+	if cc.has_argument('-mavx512f')
+		machine_args += '-mno-avx512f'
+	endif
 endif
 
 dpdk_conf.set('RTE_CACHE_LINE_SIZE', 64)
diff --git a/mk/rte.cpuflags.mk b/mk/rte.cpuflags.mk
index 43ed84155b..8fdb0cc2c3 100644
--- a/mk/rte.cpuflags.mk
+++ b/mk/rte.cpuflags.mk
@@ -68,6 +68,11 @@ endif
 ifneq ($(filter $(AUTO_CPUFLAGS),__AVX512F__),)
 ifeq ($(CONFIG_RTE_ENABLE_AVX512),y)
 CPUFLAGS += AVX512F
+else
+# disable compiler's AVX512F support as a workaround for Bug 97
+ifeq ($(shell $(CC) --target-help | grep -q mavx512f && echo 1), 1)
+MACHINE_CFLAGS += -mno-avx512f
+endif
 endif
 endif
 
-- 
2.11.0
