[Qemu-devel] [6011] TCG x86/x86-64: use move with zero-extend for loads/stores

[Qemu-devel] [6011] TCG x86/x86-64: use move with zero-extend for loads/stores

[Aurelien Jarno]

Revision: 6011
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=6011
Author:   aurel32
Date:     2008-12-13 18:57:21 +0000 (Sat, 13 Dec 2008)

Log Message:
-----------
TCG x86/x86-64: use move with zero-extend for loads/stores

Starting with version 4.3, gcc returns the result of a function in
rax/eax/ax/al instead of rax/eax, depending of the return type. As
a consequence we should use a zero extend moe in TCG loads/stores.

See http://gcc.gnu.org/ml/gcc/2008-01/msg00052.html for more details.

A big thanks to malc who founds the problem and wrote the x86 patch.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

Modified Paths:
--------------
    trunk/tcg/i386/tcg-target.c
    trunk/tcg/x86_64/tcg-target.c

Modified: trunk/tcg/i386/tcg-target.c
===================================================================
--- trunk/tcg/i386/tcg-target.c	2008-12-13 18:57:12 UTC (rev 6010)
+++ trunk/tcg/i386/tcg-target.c	2008-12-13 18:57:21 UTC (rev 6011)
@@ -525,7 +525,13 @@
         tcg_out_modrm(s, 0xbf | P_EXT, data_reg, TCG_REG_EAX);
         break;
     case 0:
+        /* movzbl */
+        tcg_out_modrm(s, 0xb6 | P_EXT, data_reg, TCG_REG_EAX);
+        break;
     case 1:
+        /* movzwl */
+        tcg_out_modrm(s, 0xb7 | P_EXT, data_reg, TCG_REG_EAX);
+        break;
     case 2:
     default:
         tcg_out_mov(s, data_reg, TCG_REG_EAX);

Modified: trunk/tcg/x86_64/tcg-target.c
===================================================================
--- trunk/tcg/x86_64/tcg-target.c	2008-12-13 18:57:12 UTC (rev 6010)
+++ trunk/tcg/x86_64/tcg-target.c	2008-12-13 18:57:21 UTC (rev 6011)
@@ -575,7 +575,13 @@
         tcg_out_modrm(s, 0x63 | P_REXW, data_reg, TCG_REG_RAX);
         break;
     case 0:
+        /* movzbq */
+        tcg_out_modrm(s, 0xb6 | P_EXT | P_REXW, data_reg, TCG_REG_RAX);
+        break;
     case 1:
+        /* movzwq */
+        tcg_out_modrm(s, 0xb7 | P_EXT | P_REXW, data_reg, TCG_REG_RAX);
+        break;
     case 2:
     default:
         /* movl */