[Valgrind-developers] [valgrind] VEX/priv/guest_riscv64_toIR.c: Recognize both fence and fence.tso

[Mark W. <ma...@so...>]

https://sourceware.org/git/gitweb.cgi?p=valgrind.git;h=e1fb410b5c72c89b6702e81aca91dee9250608ab

commit e1fb410b5c72c89b6702e81aca91dee9250608ab
Author: Mark Wielaard <ma...@kl...>
Date:   Sat Dec 14 22:11:57 2024 +0000

    VEX/priv/guest_riscv64_toIR.c: Recognize both fence and fence.tso
    
    fence.tso is used for __atomic_thread_fence (__ATOMIC_ACQ_REL)
    
    There are 3 fence variants.
    
    fence.tso  fm set to 1000 and pred and succ both set to 0011.
    fence with fm set to 0000 and pred and succ both set to 1111.
    fence with fm set to 0000 and pred and succ with some iorw flags set.
    
    https://bugs.kde.org/show_bug.cgi?id=468575#c42

Diff:
---
 VEX/priv/guest_riscv64_toIR.c | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/VEX/priv/guest_riscv64_toIR.c b/VEX/priv/guest_riscv64_toIR.c
index 93ea5a173d..e76a602a0d 100644
--- a/VEX/priv/guest_riscv64_toIR.c
+++ b/VEX/priv/guest_riscv64_toIR.c
@@ -1610,19 +1610,26 @@ static Bool dis_RV64I(/*MB_OUT*/ DisResult* dres,
    }
 
    /* ------------------------ fence ------------------------ */
-   if (INSN(19, 0) == 0b00000000000000001111 && INSN(31, 28) == 0b0000) {
+   if (INSN(19, 0) == 0b00000000000000001111) {
+      UInt   fm = INSN(31, 28);
       UInt succ = INSN(23, 20);
       UInt pred = INSN(27, 24);
-      stmt(irsb, IRStmt_MBE(Imbe_Fence));
-      if (pred == 0b1111 && succ == 0b1111)
-         DIP("fence\n");
-      else
-         DIP("fence %s%s%s%s,%s%s%s%s\n", (pred & 0x8) ? "i" : "",
-             (pred & 0x4) ? "o" : "", (pred & 0x2) ? "r" : "",
-             (pred & 0x1) ? "w" : "", (succ & 0x8) ? "i" : "",
-             (succ & 0x4) ? "o" : "", (succ & 0x2) ? "r" : "",
-             (succ & 0x1) ? "w" : "");
-      return True;
+      if ((fm == 0b1000 && pred == 0b0011 && succ == 0b0011)
+          || fm == 0b0000)
+      {
+         if (fm == 0b1000)
+            DIP("fence.tso\n");
+         else if (pred == 0b1111 && succ == 0b1111)
+            DIP("fence\n");
+         else
+            DIP("fence %s%s%s%s,%s%s%s%s\n", (pred & 0x8) ? "i" : "",
+                (pred & 0x4) ? "o" : "", (pred & 0x2) ? "r" : "",
+                (pred & 0x1) ? "w" : "", (succ & 0x8) ? "i" : "",
+                (succ & 0x4) ? "o" : "", (succ & 0x2) ? "r" : "",
+                (succ & 0x1) ? "w" : "");
+         stmt(irsb, IRStmt_MBE(Imbe_Fence));
+         return True;
+      }
    }
 
    /* ------------------------ ecall ------------------------ */