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[97.113.165.104]) by smtp.gmail.com with ESMTPSA id a17sm3532594pfk.173.2017.10.20.16.20.40 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 20 Oct 2017 16:20:40 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Date: Fri, 20 Oct 2017 16:19:41 -0700 Message-Id: <20171020232023.15010-11-richard.henderson@linaro.org> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20171020232023.15010-1-richard.henderson@linaro.org> References: <20171020232023.15010-1-richard.henderson@linaro.org> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:400e:c00::242 Subject: [Qemu-devel] [PATCH v7 10/52] tcg: Avoid loops against variable bounds X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: pbonzini@redhat.com, cota@braap.org, f4bug@amsat.org, Richard Henderson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Richard Henderson Copy s->nb_globals or s->nb_temps to a local variable for the purposes of iteration. This should allow the compiler to use low-overhead looping constructs on some hosts. Reviewed-by: Emilio G. Cota Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daudé --- tcg/tcg.c | 27 ++++++++++----------------- 1 file changed, 10 insertions(+), 17 deletions(-) diff --git a/tcg/tcg.c b/tcg/tcg.c index d08e34a9d8..840e65c0d4 100644 --- a/tcg/tcg.c +++ b/tcg/tcg.c @@ -1159,23 +1159,16 @@ void tcg_gen_callN(TCGContext *s, void *func, TCGArg ret, static void tcg_reg_alloc_start(TCGContext *s) { - int i; + int i, n; TCGTemp *ts; - for(i = 0; i < s->nb_globals; i++) { + + for (i = 0, n = s->nb_globals; i < n; i++) { ts = &s->temps[i]; - if (ts->fixed_reg) { - ts->val_type = TEMP_VAL_REG; - } else { - ts->val_type = TEMP_VAL_MEM; - } + ts->val_type = (ts->fixed_reg ? TEMP_VAL_REG : TEMP_VAL_MEM); } - for(i = s->nb_globals; i < s->nb_temps; i++) { + for (n = s->nb_temps; i < n; i++) { ts = &s->temps[i]; - if (ts->temp_local) { - ts->val_type = TEMP_VAL_MEM; - } else { - ts->val_type = TEMP_VAL_DEAD; - } + ts->val_type = (ts->temp_local ? TEMP_VAL_MEM : TEMP_VAL_DEAD); ts->mem_allocated = 0; ts->fixed_reg = 0; } @@ -2277,9 +2270,9 @@ static void temp_save(TCGContext *s, TCGTemp *ts, TCGRegSet allocated_regs) temporary registers needs to be allocated to store a constant. */ static void save_globals(TCGContext *s, TCGRegSet allocated_regs) { - int i; + int i, n; - for (i = 0; i < s->nb_globals; i++) { + for (i = 0, n = s->nb_globals; i < n; i++) { temp_save(s, &s->temps[i], allocated_regs); } } @@ -2289,9 +2282,9 @@ static void save_globals(TCGContext *s, TCGRegSet allocated_regs) temporary registers needs to be allocated to store a constant. */ static void sync_globals(TCGContext *s, TCGRegSet allocated_regs) { - int i; + int i, n; - for (i = 0; i < s->nb_globals; i++) { + for (i = 0, n = s->nb_globals; i < n; i++) { TCGTemp *ts = &s->temps[i]; tcg_debug_assert(ts->val_type != TEMP_VAL_REG || ts->fixed_reg