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From: "Paul A. Clarke" <pc@us.ibm.com>
To: david@gibson.dropbear.id.au
Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org
Subject: [Qemu-devel] [PATCH] ppc: Fix xsmaddmdp and friends
Date: Wed, 21 Aug 2019 10:28:41 -0500	[thread overview]
Message-ID: <1566401321-22419-1-git-send-email-pc@us.ibm.com> (raw)

From: "Paul A. Clarke" <pc@us.ibm.com>

A class of instructions of the form:
  op Target,A,B
which operate like:
  Target = Target * A + B
have a bit set which distinguishes them from instructions that operate as:
  Target = Target * B + A

This bit is not being checked properly (using PPC_BIT macro), so all
instructions in this class are operating incorrectly as the second form
above.  The bit was being checked as if it were part of a 64-bit
instruction opcode, rather than a proper 32-bit opcode.  Fix by using the
macro (PPC_BIT32) which treats the opcode as a 32-bit quantity.

Signed-off-by: Paul A. Clarke <pc@us.ibm.com>
---
 target/ppc/translate/vsx-impl.inc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/ppc/translate/vsx-impl.inc.c b/target/ppc/translate/vsx-impl.inc.c
index 3922686..8287e27 100644
--- a/target/ppc/translate/vsx-impl.inc.c
+++ b/target/ppc/translate/vsx-impl.inc.c
@@ -1308,7 +1308,7 @@ static void gen_##name(DisasContext *ctx)                                     \
     }                                                                         \
     xt = gen_vsr_ptr(xT(ctx->opcode));                                        \
     xa = gen_vsr_ptr(xA(ctx->opcode));                                        \
-    if (ctx->opcode & PPC_BIT(25)) {                                          \
+    if (ctx->opcode & PPC_BIT32(25)) {                                        \
         /*                                                                    \
          * AxT + B                                                            \
          */                                                                   \
-- 
1.8.3.1



             reply	other threads:[~2019-08-21 15:29 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-21 15:28 Paul A. Clarke [this message]
2019-08-21 22:56 ` [Qemu-devel] [PATCH] ppc: Fix xsmaddmdp and friends David Gibson
2019-08-28 17:32   ` [Qemu-devel] [Qemu-ppc] " Laurent Vivier
2019-08-28 23:28     ` David Gibson

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