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From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org, qemu-arm@nongnu.org
Subject: [PATCH v4 13/23] target/arm: Improve gen_top_byte_ignore
Date: Thu, 28 Jan 2021 12:41:31 -1000	[thread overview]
Message-ID: <20210128224141.638790-14-richard.henderson@linaro.org> (raw)
In-Reply-To: <20210128224141.638790-1-richard.henderson@linaro.org>

Use simple arithmetic instead of a conditional
move when tbi0 != tbi1.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/translate-a64.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index ffc060e5d7..3ec0dc17d8 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -183,17 +183,20 @@ static void gen_top_byte_ignore(DisasContext *s, TCGv_i64 dst,
         /* Sign-extend from bit 55.  */
         tcg_gen_sextract_i64(dst, src, 0, 56);
 
-        if (tbi != 3) {
-            TCGv_i64 tcg_zero = tcg_const_i64(0);
-
-            /*
-             * The two TBI bits differ.
-             * If tbi0, then !tbi1: only use the extension if positive.
-             * if !tbi0, then tbi1: only use the extension if negative.
-             */
-            tcg_gen_movcond_i64(tbi == 1 ? TCG_COND_GE : TCG_COND_LT,
-                                dst, dst, tcg_zero, dst, src);
-            tcg_temp_free_i64(tcg_zero);
+        switch (tbi) {
+        case 1:
+            /* tbi0 but !tbi1: only use the extension if positive */
+            tcg_gen_and_i64(dst, dst, src);
+            break;
+        case 2:
+            /* !tbi0 but tbi1: only use the extension if negative */
+            tcg_gen_or_i64(dst, dst, src);
+            break;
+        case 3:
+            /* tbi0 and tbi1: always use the extension */
+            break;
+        default:
+            g_assert_not_reached();
         }
     }
 }
-- 
2.25.1



  parent reply	other threads:[~2021-01-28 22:55 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-28 22:41 [PATCH v4 00/23] target-arm: Implement ARMv8.5-MemTag, user mode Richard Henderson
2021-01-28 22:41 ` [PATCH v4 01/23] tcg: Introduce target-specific page data for user-only Richard Henderson
2021-02-02 14:29   ` Peter Maydell
2021-02-03  2:40     ` Richard Henderson
2021-02-03  5:49       ` Richard Henderson
2021-02-03 15:33         ` Alex Bennée
2021-01-28 22:41 ` [PATCH v4 02/23] linux-user: Introduce PAGE_ANON Richard Henderson
2021-01-28 22:41 ` [PATCH v4 03/23] exec: Use uintptr_t for guest_base Richard Henderson
2021-02-02 14:31   ` Peter Maydell
2021-01-28 22:41 ` [PATCH v4 04/23] exec: Use uintptr_t in cpu_ldst.h Richard Henderson
2021-02-02 14:32   ` Peter Maydell
2021-02-02 15:30   ` Philippe Mathieu-Daudé
2021-01-28 22:41 ` [PATCH v4 05/23] exec: Improve types for guest_addr_valid Richard Henderson
2021-02-02 14:33   ` Peter Maydell
2021-02-02 15:31   ` Philippe Mathieu-Daudé
2021-01-28 22:41 ` [PATCH v4 06/23] linux-user: Check for overflow in access_ok Richard Henderson
2021-01-28 22:41 ` [PATCH v4 07/23] linux-user: Tidy VERIFY_READ/VERIFY_WRITE Richard Henderson
2021-01-28 22:41 ` [PATCH v4 08/23] bsd-user: " Richard Henderson
2021-01-28 22:41 ` [PATCH v4 09/23] linux-user: Do not use guest_addr_valid for h2g_valid Richard Henderson
2021-02-02 14:34   ` Peter Maydell
2021-01-28 22:41 ` [PATCH v4 10/23] linux-user: Fix guest_addr_valid vs reserved_va Richard Henderson
2021-02-02 14:35   ` Peter Maydell
2021-01-28 22:41 ` [PATCH v4 11/23] exec: Add support for TARGET_TAGGED_ADDRESSES Richard Henderson
2021-02-02 15:05   ` Peter Maydell
2021-01-28 22:41 ` [PATCH v4 12/23] linux-user/aarch64: Implement PR_TAGGED_ADDR_ENABLE Richard Henderson
2021-02-02 14:37   ` Peter Maydell
2021-01-28 22:41 ` Richard Henderson [this message]
2021-02-02 14:40   ` [PATCH v4 13/23] target/arm: Improve gen_top_byte_ignore Peter Maydell
2021-01-28 22:41 ` [PATCH v4 14/23] target/arm: Use the proper TBI settings for linux-user Richard Henderson
2021-02-02 14:41   ` Peter Maydell
2021-01-28 22:41 ` [PATCH v4 15/23] linux-user/aarch64: Implement PR_MTE_TCF and PR_MTE_TAG Richard Henderson
2021-02-02 14:43   ` Peter Maydell
2021-01-28 22:41 ` [PATCH v4 16/23] linux-user/aarch64: Implement PROT_MTE Richard Henderson
2021-01-28 22:41 ` [PATCH v4 17/23] target/arm: Split out syndrome.h from internals.h Richard Henderson
2021-02-02 14:44   ` Peter Maydell
2021-01-28 22:41 ` [PATCH v4 18/23] linux-user/aarch64: Pass syndrome to EXC_*_ABORT Richard Henderson
2021-02-02 14:44   ` Peter Maydell
2021-01-28 22:41 ` [PATCH v4 19/23] linux-user/aarch64: Signal SEGV_MTESERR for sync tag check fault Richard Henderson
2021-02-02 14:45   ` Peter Maydell
2021-01-28 22:41 ` [PATCH v4 20/23] linux-user/aarch64: Signal SEGV_MTEAERR for async tag check error Richard Henderson
2021-02-02 14:46   ` Peter Maydell
2021-01-28 22:41 ` [PATCH v4 21/23] target/arm: Add allocation tag storage for user mode Richard Henderson
2021-02-02 14:46   ` Peter Maydell
2021-01-28 22:41 ` [PATCH v4 22/23] target/arm: Enable MTE for user-only Richard Henderson
2021-02-02 14:47   ` Peter Maydell
2021-01-28 22:41 ` [PATCH v4 23/23] tests/tcg/aarch64: Add mte smoke tests Richard Henderson
2021-02-02 14:49   ` Peter Maydell
2021-01-28 23:15 ` [PATCH v4 00/23] target-arm: Implement ARMv8.5-MemTag, user mode no-reply

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