SH4: Fix swap.b

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

        SWAP.B Rm,Rn
                Rm → swap lower 2 bytes → 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)

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5471 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
aurel32 2008-10-12 23:32:40 +00:00
parent f71903d020
commit c69e3264c3
1 changed files with 4 additions and 1 deletions

View File

@ -683,7 +683,9 @@ void _decode_opc(DisasContext * ctx)
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 @@ void _decode_opc(DisasContext * ctx)
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);
}