[Qemu-devel] [PATCH v2 7/7] tcg-i386: Make use of zero-extended memory helper routines

[Richard Henderson <rth@twiddle.net>]

For 8 and 16-bit unsigned loads, rely on the zero-extension
from the helper and use a smaller 32-bit move insn.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 tcg/i386/tcg-target.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
index 5aee0fa..e9d6c49 100644
--- a/tcg/i386/tcg-target.c
+++ b/tcg/i386/tcg-target.c
@@ -1520,20 +1520,17 @@ static void tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
     case 1 | 4:
         tcg_out_ext16s(s, data_reg, TCG_REG_EAX, P_REXW);
         break;
-    case 0:
-        tcg_out_ext8u(s, data_reg, TCG_REG_EAX);
-        break;
-    case 1:
-        tcg_out_ext16u(s, data_reg, TCG_REG_EAX);
-        break;
-    case 2:
-        tcg_out_mov(s, TCG_TYPE_I32, data_reg, TCG_REG_EAX);
-        break;
 #if TCG_TARGET_REG_BITS == 64
     case 2 | 4:
         tcg_out_ext32s(s, data_reg, TCG_REG_EAX);
         break;
 #endif
+    case 0:
+    case 1:
+        /* Note that the helpers have zero-extended to tcg_target_long.  */
+    case 2:
+        tcg_out_mov(s, TCG_TYPE_I32, data_reg, TCG_REG_EAX);
+        break;
     case 3:
         if (TCG_TARGET_REG_BITS == 64) {
             tcg_out_mov(s, TCG_TYPE_I64, data_reg, TCG_REG_RAX);
-- 
1.8.1.4