From 8e2dd74f0afd3ef3358f1cca05afb20bda670207 Mon Sep 17 00:00:00 2001 From: Konstantin Ananyev Date: Mon, 26 Apr 2021 14:35:19 +0100 Subject: [PATCH] acl: fix build with GCC 11 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit gcc 11 with '-O2' complains about some variables being used without being initialized: In function ‘start_flow_avx512x8’, inlined from ‘search_trie_avx512x8.constprop’ at acl_run_avx512_common.h:317: lib/librte_acl/acl_run_avx512_common.h:210:13: warning: ‘pdata’ is used uninitialized [-Wuninitialized] In function ‘search_trie_avx512x8.constprop’: lib/librte_acl/acl_run_avx512_common.h:314:32: note: ‘pdata’ declared here ... Indeed, these variables are not explicitly initialized, but this is done intentionally. We rely on constant mask value that we pass to start_flow*() functions as a parameter to mask out uninitialized values. Note that '-O3' doesn't produce this warning. Anyway, to support clean build with gcc-11 this patch adds explicit initialization for these variables. I checked the output binary: with '-O3' both clang and gcc 10/11 generate no extra code for it. Also performance test didn't reveal any regressions. Bugzilla ID: 673 Fixes: b64c2295f7fc ("acl: add 256-bit AVX512 classify method") Fixes: 45da22e42ec3 ("acl: add 512-bit AVX512 classify method") Cc: stable@dpdk.org Reported-by: Ali Alnubani Signed-off-by: Konstantin Ananyev --- lib/acl/acl_run_avx512_common.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/lib/acl/acl_run_avx512_common.h b/lib/acl/acl_run_avx512_common.h index fafaf591e8..fbad74d459 100644 --- a/lib/acl/acl_run_avx512_common.h +++ b/lib/acl/acl_run_avx512_common.h @@ -303,6 +303,28 @@ _F_(match_check_process)(struct acl_flow_avx512 *flow, uint32_t fm[2], } } +static inline void +_F_(reset_flow_vars)(_T_simd di[2], _T_simd idx[2], _T_simd pdata[4], + _T_simd tr_lo[2], _T_simd tr_hi[2]) +{ + di[0] = _M_SI_(setzero)(); + di[1] = _M_SI_(setzero)(); + + idx[0] = _M_SI_(setzero)(); + idx[1] = _M_SI_(setzero)(); + + pdata[0] = _M_SI_(setzero)(); + pdata[1] = _M_SI_(setzero)(); + pdata[2] = _M_SI_(setzero)(); + pdata[3] = _M_SI_(setzero)(); + + tr_lo[0] = _M_SI_(setzero)(); + tr_lo[1] = _M_SI_(setzero)(); + + tr_hi[0] = _M_SI_(setzero)(); + tr_hi[1] = _M_SI_(setzero)(); +} + /* * Perform search for up to (2 * _N_) flows in parallel. * Use two sets of metadata, each serves _N_ flows max. @@ -313,6 +335,8 @@ _F_(search_trie)(struct acl_flow_avx512 *flow) uint32_t fm[2]; _T_simd di[2], idx[2], in[2], pdata[4], tr_lo[2], tr_hi[2]; + _F_(reset_flow_vars)(di, idx, pdata, tr_lo, tr_hi); + /* first 1B load */ _F_(start_flow)(flow, _SIMD_MASK_BIT_, _SIMD_MASK_MAX_, &pdata[0], &idx[0], &di[0]); -- 2.20.1