diff mbox series

[v4,02/54] tcg/i386: Generalize multi-part load overlap test

Message ID 20230503065729.1745843-3-richard.henderson@linaro.org
State Superseded
Headers show
Series tcg: Simplify calls to load/store helpers | expand

Commit Message

Richard Henderson May 3, 2023, 6:56 a.m. UTC 
Test for both base and index; use datahi as a temporary, overwritten
by the final load.  Always perform the loads in ascending order, so
that any (user-only) fault sees the correct address.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/i386/tcg-target.c.inc | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)
diff mbox series

Patch

diff --git a/tcg/i386/tcg-target.c.inc b/tcg/i386/tcg-target.c.inc
index cfa2349b03..173f3c3172 100644
--- a/tcg/i386/tcg-target.c.inc
+++ b/tcg/i386/tcg-target.c.inc
@@ -2221,23 +2221,22 @@  static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
         if (TCG_TARGET_REG_BITS == 64) {
             tcg_out_modrm_sib_offset(s, movop + P_REXW + seg, datalo,
                                      base, index, 0, ofs);
+            break;
+        }
+        if (use_movbe) {
+            TCGReg t = datalo;
+            datalo = datahi;
+            datahi = t;
+        }
+        if (base == datalo || index == datalo) {
+            tcg_out_modrm_sib_offset(s, OPC_LEA, datahi, base, index, 0, ofs);
+            tcg_out_modrm_offset(s, movop + seg, datalo, datahi, 0);
+            tcg_out_modrm_offset(s, movop + seg, datahi, datahi, 4);
         } else {
-            if (use_movbe) {
-                TCGReg t = datalo;
-                datalo = datahi;
-                datahi = t;
-            }
-            if (base != datalo) {
-                tcg_out_modrm_sib_offset(s, movop + seg, datalo,
-                                         base, index, 0, ofs);
-                tcg_out_modrm_sib_offset(s, movop + seg, datahi,
-                                         base, index, 0, ofs + 4);
-            } else {
-                tcg_out_modrm_sib_offset(s, movop + seg, datahi,
-                                         base, index, 0, ofs + 4);
-                tcg_out_modrm_sib_offset(s, movop + seg, datalo,
-                                         base, index, 0, ofs);
-            }
+            tcg_out_modrm_sib_offset(s, movop + seg, datalo,
+                                     base, index, 0, ofs);
+            tcg_out_modrm_sib_offset(s, movop + seg, datahi,
+                                     base, index, 0, ofs + 4);
         }
         break;
     default: