qemu-devel
[Top][All Lists]
Advanced

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

Re: [PATCH for-6.1] tcg/i386: Split P_VEXW from P_REXW


From: Richard Henderson
Subject: Re: [PATCH for-6.1] tcg/i386: Split P_VEXW from P_REXW
Date: Thu, 12 Aug 2021 08:29:04 -1000
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0

PIng for review, or this slips to 6.2.

On 8/10/21 1:25 PM, Richard Henderson wrote:
We need to be able to represent VEX.W on a 32-bit host, where REX.W
will always be zero.  Fixes the encoding for VPSLLVQ and VPSRLVQ.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/385
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
  tcg/i386/tcg-target.c.inc | 13 +++++++------
  1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/tcg/i386/tcg-target.c.inc b/tcg/i386/tcg-target.c.inc
index 98d924b91a..997510109d 100644
--- a/tcg/i386/tcg-target.c.inc
+++ b/tcg/i386/tcg-target.c.inc
@@ -241,8 +241,9 @@ static bool tcg_target_const_match(int64_t val, TCGType 
type, int ct)
  #define P_EXT         0x100           /* 0x0f opcode prefix */
  #define P_EXT38         0x200           /* 0x0f 0x38 opcode prefix */
  #define P_DATA16        0x400           /* 0x66 opcode prefix */
+#define P_VEXW          0x1000          /* Set VEX.W = 1 */
  #if TCG_TARGET_REG_BITS == 64
-# define P_REXW         0x1000          /* Set REX.W = 1 */
+# define P_REXW         P_VEXW          /* Set REX.W = 1; match VEXW */
  # define P_REXB_R       0x2000          /* REG field as byte register */
  # define P_REXB_RM      0x4000          /* R/M field as byte register */
  # define P_GS           0x8000          /* gs segment override */
@@ -410,13 +411,13 @@ static bool tcg_target_const_match(int64_t val, TCGType 
type, int ct)
  #define OPC_VPBROADCASTW (0x79 | P_EXT38 | P_DATA16)
  #define OPC_VPBROADCASTD (0x58 | P_EXT38 | P_DATA16)
  #define OPC_VPBROADCASTQ (0x59 | P_EXT38 | P_DATA16)
-#define OPC_VPERMQ      (0x00 | P_EXT3A | P_DATA16 | P_REXW)
+#define OPC_VPERMQ      (0x00 | P_EXT3A | P_DATA16 | P_VEXW)
  #define OPC_VPERM2I128  (0x46 | P_EXT3A | P_DATA16 | P_VEXL)
  #define OPC_VPSLLVD     (0x47 | P_EXT38 | P_DATA16)
-#define OPC_VPSLLVQ     (0x47 | P_EXT38 | P_DATA16 | P_REXW)
+#define OPC_VPSLLVQ     (0x47 | P_EXT38 | P_DATA16 | P_VEXW)
  #define OPC_VPSRAVD     (0x46 | P_EXT38 | P_DATA16)
  #define OPC_VPSRLVD     (0x45 | P_EXT38 | P_DATA16)
-#define OPC_VPSRLVQ     (0x45 | P_EXT38 | P_DATA16 | P_REXW)
+#define OPC_VPSRLVQ     (0x45 | P_EXT38 | P_DATA16 | P_VEXW)
  #define OPC_VZEROUPPER  (0x77 | P_EXT)
  #define OPC_XCHG_ax_r32       (0x90)
@@ -576,7 +577,7 @@ static void tcg_out_vex_opc(TCGContext *s, int opc, int r, int v, /* Use the two byte form if possible, which cannot encode
         VEX.W, VEX.B, VEX.X, or an m-mmmm field other than P_EXT.  */
-    if ((opc & (P_EXT | P_EXT38 | P_EXT3A | P_REXW)) == P_EXT
+    if ((opc & (P_EXT | P_EXT38 | P_EXT3A | P_VEXW)) == P_EXT
          && ((rm | index) & 8) == 0) {
          /* Two byte VEX prefix.  */
          tcg_out8(s, 0xc5);
@@ -601,7 +602,7 @@ static void tcg_out_vex_opc(TCGContext *s, int opc, int r, 
int v,
          tmp |= (rm & 8 ? 0 : 0x20);            /* VEX.B */
          tcg_out8(s, tmp);
- tmp = (opc & P_REXW ? 0x80 : 0); /* VEX.W */
+        tmp = (opc & P_VEXW ? 0x80 : 0);       /* VEX.W */
      }
tmp |= (opc & P_VEXL ? 0x04 : 0); /* VEX.L */





reply via email to

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