{"id":811679,"url":"http://patchwork.ozlabs.org/api/1.2/patches/811679/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170908163859.29820-1-richard.henderson@linaro.org/","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/1.2/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":"","list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20170908163859.29820-1-richard.henderson@linaro.org>","list_archive_url":null,"date":"2017-09-08T16:38:59","name":"target/arm: Avoid an extra temporary for store_exclusive","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"124b1e54a77d8f50a08e48edabc01bd31bc388f6","submitter":{"id":72104,"url":"http://patchwork.ozlabs.org/api/1.2/people/72104/?format=json","name":"Richard Henderson","email":"richard.henderson@linaro.org"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170908163859.29820-1-richard.henderson@linaro.org/mbox/","series":[{"id":2246,"url":"http://patchwork.ozlabs.org/api/1.2/series/2246/?format=json","web_url":"http://patchwork.ozlabs.org/project/qemu-devel/list/?series=2246","date":"2017-09-08T16:38:59","name":"target/arm: Avoid an extra temporary for store_exclusive","version":1,"mbox":"http://patchwork.ozlabs.org/series/2246/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/811679/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/811679/checks/","tags":{},"related":[],"headers":{"Return-Path":"<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=pass (mailfrom) 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-0700","Message-Id":"<20170908163859.29820-1-richard.henderson@linaro.org>","X-Mailer":"git-send-email 2.13.5","X-detected-operating-system":"by eggs.gnu.org: Genre and OS details not\n\trecognized.","X-Received-From":"2607:f8b0:400e:c05::22f","Subject":"[Qemu-devel] [PATCH] target/arm: Avoid an extra temporary for\n\tstore_exclusive","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.21","Precedence":"list","List-Id":"<qemu-devel.nongnu.org>","List-Unsubscribe":"<https://lists.nongnu.org/mailman/options/qemu-devel>,\n\t<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>","List-Archive":"<http://lists.nongnu.org/archive/html/qemu-devel/>","List-Post":"<mailto:qemu-devel@nongnu.org>","List-Help":"<mailto:qemu-devel-request@nongnu.org?subject=help>","List-Subscribe":"<https://lists.nongnu.org/mailman/listinfo/qemu-devel>,\n\t<mailto:qemu-devel-request@nongnu.org?subject=subscribe>","Cc":"peter.maydell@linaro.org, qemu-arm@nongnu.org, patches@linaro.org","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"\"Qemu-devel\"\n\t<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>"},"content":"Instead of copying addr to a local temp, reuse the value (which we\nhave just compared as equal) already saved in cpu_exclusive_addr.\n\nSigned-off-by: Richard Henderson <richard.henderson@linaro.org>\n---\n target/arm/translate-a64.c | 26 +++++++++-----------------\n 1 file changed, 9 insertions(+), 17 deletions(-)","diff":"diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c\nindex 9017e30510..114e21cc58 100644\n--- a/target/arm/translate-a64.c\n+++ b/target/arm/translate-a64.c\n@@ -1894,7 +1894,7 @@ static void gen_load_exclusive(DisasContext *s, int rt, int rt2,\n }\n \n static void gen_store_exclusive(DisasContext *s, int rd, int rt, int rt2,\n-                                TCGv_i64 inaddr, int size, int is_pair)\n+                                TCGv_i64 addr, int size, int is_pair)\n {\n     /* if (env->exclusive_addr == addr && env->exclusive_val == [addr]\n      *     && (!is_pair || env->exclusive_high == [addr + datasize])) {\n@@ -1910,13 +1910,8 @@ static void gen_store_exclusive(DisasContext *s, int rd, int rt, int rt2,\n      */\n     TCGLabel *fail_label = gen_new_label();\n     TCGLabel *done_label = gen_new_label();\n-    TCGv_i64 addr = tcg_temp_local_new_i64();\n     TCGv_i64 tmp;\n \n-    /* Copy input into a local temp so it is not trashed when the\n-     * basic block ends at the branch insn.\n-     */\n-    tcg_gen_mov_i64(addr, inaddr);\n     tcg_gen_brcond_i64(TCG_COND_NE, addr, cpu_exclusive_addr, fail_label);\n \n     tmp = tcg_temp_new_i64();\n@@ -1927,27 +1922,24 @@ static void gen_store_exclusive(DisasContext *s, int rd, int rt, int rt2,\n             } else {\n                 tcg_gen_concat32_i64(tmp, cpu_reg(s, rt2), cpu_reg(s, rt));\n             }\n-            tcg_gen_atomic_cmpxchg_i64(tmp, addr, cpu_exclusive_val, tmp,\n+            tcg_gen_atomic_cmpxchg_i64(tmp, cpu_exclusive_addr,\n+                                       cpu_exclusive_val, tmp,\n                                        get_mem_index(s),\n                                        MO_64 | MO_ALIGN | s->be_data);\n             tcg_gen_setcond_i64(TCG_COND_NE, tmp, tmp, cpu_exclusive_val);\n         } else if (s->be_data == MO_LE) {\n-            gen_helper_paired_cmpxchg64_le(tmp, cpu_env, addr, cpu_reg(s, rt),\n-                                           cpu_reg(s, rt2));\n+            gen_helper_paired_cmpxchg64_le(tmp, cpu_env, cpu_exclusive_addr,\n+                                           cpu_reg(s, rt), cpu_reg(s, rt2));\n         } else {\n-            gen_helper_paired_cmpxchg64_be(tmp, cpu_env, addr, cpu_reg(s, rt),\n-                                           cpu_reg(s, rt2));\n+            gen_helper_paired_cmpxchg64_be(tmp, cpu_env, cpu_exclusive_addr,\n+                                           cpu_reg(s, rt), cpu_reg(s, rt2));\n         }\n     } else {\n-        TCGv_i64 val = cpu_reg(s, rt);\n-        tcg_gen_atomic_cmpxchg_i64(tmp, addr, cpu_exclusive_val, val,\n-                                   get_mem_index(s),\n+        tcg_gen_atomic_cmpxchg_i64(tmp, cpu_exclusive_addr, cpu_exclusive_val,\n+                                   cpu_reg(s, rt), get_mem_index(s),\n                                    size | MO_ALIGN | s->be_data);\n         tcg_gen_setcond_i64(TCG_COND_NE, tmp, tmp, cpu_exclusive_val);\n     }\n-\n-    tcg_temp_free_i64(addr);\n-\n     tcg_gen_mov_i64(cpu_reg(s, rd), tmp);\n     tcg_temp_free_i64(tmp);\n     tcg_gen_br(done_label);\n","prefixes":[]}