From: Nicholas Piggin <npiggin@gmail.com>
To: Daniel Henrique Barboza <danielhb413@gmail.com>
Cc: Nicholas Piggin <npiggin@gmail.com>,
Richard Henderson <richard.henderson@linaro.org>,
qemu-ppc@nongnu.org, qemu-devel@nongnu.org,
qemu-stable@nongnu.org
Subject: [PATCH 3/4] target/ppc: Remove larx/stcx. memory barrier semantics
Date: Sun, 4 Jun 2023 20:28:56 +1000 [thread overview]
Message-ID: <20230604102858.148584-3-npiggin@gmail.com> (raw)
In-Reply-To: <20230604102858.148584-1-npiggin@gmail.com>
larx and stcx. are not defined to order any memory operations.
Remove the barriers.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
target/ppc/translate.c | 11 -----------
1 file changed, 11 deletions(-)
diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index 5195047146..77e1c5abb6 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -3591,7 +3591,6 @@ static void gen_load_locked(DisasContext *ctx, MemOp memop)
tcg_gen_movi_tl(cpu_reserve_size, memop_size(memop));
tcg_gen_qemu_ld_tl(gpr, t0, ctx->mem_idx, memop | MO_ALIGN);
tcg_gen_mov_tl(cpu_reserve_val, gpr);
- tcg_gen_mb(TCG_MO_ALL | TCG_BAR_LDAQ);
}
#define LARX(name, memop) \
@@ -3835,11 +3834,6 @@ static void gen_conditional_store(DisasContext *ctx, MemOp memop)
gen_set_label(l1);
- /*
- * Address mismatch implies failure. But we still need to provide
- * the memory barrier semantics of the instruction.
- */
- tcg_gen_mb(TCG_MO_ALL | TCG_BAR_STRL);
tcg_gen_trunc_tl_i32(cpu_crf[0], cpu_so);
gen_set_label(l2);
@@ -3943,11 +3937,6 @@ static void gen_stqcx_(DisasContext *ctx)
tcg_gen_br(lab_over);
gen_set_label(lab_fail);
- /*
- * Address mismatch implies failure. But we still need to provide
- * the memory barrier semantics of the instruction.
- */
- tcg_gen_mb(TCG_MO_ALL | TCG_BAR_STRL);
tcg_gen_trunc_tl_i32(cpu_crf[0], cpu_so);
gen_set_label(lab_over);
--
2.40.1
next prev parent reply other threads:[~2023-06-04 10:30 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-04 10:28 [PATCH 1/4] target/ppc: Fix lqarx to set cpu_reserve Nicholas Piggin
2023-06-04 10:28 ` [PATCH 2/4] target/ppc: Ensure stcx size matches larx Nicholas Piggin
2023-06-04 16:58 ` Richard Henderson
2023-06-05 6:27 ` Nicholas Piggin
2023-06-19 15:48 ` Richard Henderson
2023-06-19 15:55 ` Peter Maydell
2023-06-19 17:02 ` Richard Henderson
2023-06-19 17:14 ` Peter Maydell
2023-06-20 3:39 ` Nicholas Piggin
2023-06-04 10:28 ` Nicholas Piggin [this message]
2023-06-04 16:12 ` [PATCH 3/4] target/ppc: Remove larx/stcx. memory barrier semantics Richard Henderson
2023-06-04 10:28 ` [PATCH 4/4] target/ppc: Rework store conditional to avoid branch Nicholas Piggin
2023-06-04 16:22 ` Richard Henderson
2023-06-04 16:05 ` [PATCH 1/4] target/ppc: Fix lqarx to set cpu_reserve Richard Henderson
2023-06-05 2:33 ` Nicholas Piggin
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