[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH v2 05/14] target/riscv: Calculate address according to XLEN

From: Richard Henderson
Subject: Re: [PATCH v2 05/14] target/riscv: Calculate address according to XLEN
Date: Wed, 10 Nov 2021 11:52:29 +0100
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0

On 11/10/21 8:04 AM, LIU Zhiwei wrote:
Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
  target/riscv/insn_trans/trans_rvd.c.inc | 23 ++---------------------
  target/riscv/insn_trans/trans_rvf.c.inc | 23 ++---------------------
  target/riscv/insn_trans/trans_rvi.c.inc | 18 ++----------------
  target/riscv/translate.c                | 13 +++++++++++++
  4 files changed, 19 insertions(+), 58 deletions(-)

diff --git a/target/riscv/insn_trans/trans_rvd.c.inc 
index 64fb0046f7..29066a8ef3 100644
--- a/target/riscv/insn_trans/trans_rvd.c.inc
+++ b/target/riscv/insn_trans/trans_rvd.c.inc
@@ -20,19 +20,10 @@
static bool trans_fld(DisasContext *ctx, arg_fld *a)
-    TCGv addr;
+    TCGv addr = get_address(ctx, a->rs1, a->imm);
      REQUIRE_EXT(ctx, RVD);

It would be better to leave the address calculation after the REQUIRE checks.

+static TCGv get_address(DisasContext *ctx, int rs1, int imm)
+    TCGv addr = temp_new(ctx);
+    TCGv src1 = get_gpr(ctx, rs1, EXT_NONE);
+    tcg_gen_addi_tl(addr, src1, imm);
+    addr = gen_pm_adjust_address(ctx, addr);
+    if (get_xl(ctx) == MXL_RV32) {
+        tcg_gen_ext32u_tl(addr, addr);
+    }
+    return addr;

I suspect the extend should come before the pointer mask and not after, but this is is a weakness in the current RVJ spec that it does not specify how the extension interacts with UXL. (The reverse ordering would allow a 64-bit os to place a 32-bit application at a base address above 4gb, which could allow address separation without paging enabled.)

I do think we should merge gen_pm_adjust_address into this function so that we only create one new temporary.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]