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From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org, "Alex Bennée" <alex.bennee@linaro.org>,
	"Kele Huang" <kele.hwang@gmail.com>,
	"Philippe Mathieu-Daudé" <f4bug@amsat.org>
Subject: [PULL for-6.0 1/2] tcg/mips: Fix SoftTLB comparison on mips backend
Date: Mon,  5 Apr 2021 07:40:16 -0700	[thread overview]
Message-ID: <20210405144017.20193-2-richard.henderson@linaro.org> (raw)
In-Reply-To: <20210405144017.20193-1-richard.henderson@linaro.org>

From: Kele Huang <kele.hwang@gmail.com>

The addrl used to compare with SoftTLB entry should be sign-extended
in common case, and it will cause constant failing in SoftTLB
comparisons for the addrl whose address is over 0x80000000 on the
emulation of 32-bit guest on 64-bit host.

This is an important performance bug fix. Spec2000 gzip rate increase
from ~45 to ~140 on Loongson 3A4000 (MIPS compatible platform).

Signed-off-by: Kele Huang <kele.hwang@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210401100457.191458-1-kele.hwang@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/mips/tcg-target.c.inc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tcg/mips/tcg-target.c.inc b/tcg/mips/tcg-target.c.inc
index 8738a3a581..8b16726242 100644
--- a/tcg/mips/tcg-target.c.inc
+++ b/tcg/mips/tcg-target.c.inc
@@ -1201,13 +1201,13 @@ static void tcg_out_tlb_load(TCGContext *s, TCGReg base, TCGReg addrl,
            load the tlb addend for the fast path.  */
         tcg_out_ld(s, TCG_TYPE_PTR, TCG_TMP2, TCG_TMP3, add_off);
     }
-    tcg_out_opc_reg(s, OPC_AND, TCG_TMP1, TCG_TMP1, addrl);
 
     /* Zero extend a 32-bit guest address for a 64-bit host. */
     if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS) {
         tcg_out_ext32u(s, base, addrl);
         addrl = base;
     }
+    tcg_out_opc_reg(s, OPC_AND, TCG_TMP1, TCG_TMP1, addrl);
 
     label_ptr[0] = s->code_ptr;
     tcg_out_opc_br(s, OPC_BNE, TCG_TMP1, TCG_TMP0);
-- 
2.25.1



  reply	other threads:[~2021-04-05 15:08 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-05 14:40 [PULL for-6.0 0/2] tcg patch queue Richard Henderson
2021-04-05 14:40 ` Richard Henderson [this message]
2021-04-05 14:40 ` [PULL for-6.0 2/2] target/alpha: fix icount handling for timer instructions Richard Henderson
2021-04-05 21:14 ` [PULL for-6.0 0/2] tcg patch queue Peter Maydell

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