[Qemu-devel] [5471] SH4: Fix swap.b

[Aurelien Jarno]

Revision: 5471
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5471
Author:   aurel32
Date:     2008-10-12 23:32:40 +0000 (Sun, 12 Oct 2008)

Log Message:
-----------
SH4: Fix swap.b

The SH4 manual documents the swap.b instruction as follows:

        SWAP.B Rm,Rn
                Rm ?\226?\134?\146 swap lower 2 bytes ?\226?\134?\146 Rn

Current QEMU code, in addition to the above, also clears the high
16 bits. The immediate breakage I saw is that htonl function applied
to  netmask of 255.255.255.0 gives 0, which breaks all networking.

(Vladimir Prus)

Modified Paths:
--------------
    trunk/target-sh4/translate.c

Modified: trunk/target-sh4/translate.c
===================================================================
--- trunk/target-sh4/translate.c        2008-10-12 21:19:57 UTC (rev 5470)
+++ trunk/target-sh4/translate.c        2008-10-12 23:32:40 UTC (rev 5471)
@@ -683,7 +683,9 @@
        return;
     case 0x6008:               /* swap.b Rm,Rn */
        {
-           TCGv high, low;
+           TCGv highw, high, low;
+           highw = tcg_temp_new(TCG_TYPE_I32);
+           tcg_gen_andi_i32(highw, REG(B7_4), 0xffff0000);
            high = tcg_temp_new(TCG_TYPE_I32);
            tcg_gen_ext8u_i32(high, REG(B7_4));
            tcg_gen_shli_i32(high, high, 8);
@@ -691,6 +693,7 @@
            tcg_gen_shri_i32(low, REG(B7_4), 8);
            tcg_gen_ext8u_i32(low, low);
            tcg_gen_or_i32(REG(B11_8), high, low);
+           tcg_gen_or_i32(REG(B11_8), REG(B11_8), highw);
            tcg_temp_free(low);
            tcg_temp_free(high);
        }