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target/arm: Convert T16 branch and exchange

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Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190904193059.26202-54-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Richard Henderson 2019-09-04 12:30:43 -07:00 committed by Peter Maydell
parent 6c6d237a86
commit a0ef077404
2 changed files with 39 additions and 41 deletions
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10
target/arm/t16.decode
View File

@ -24,6 +24,7 @@
&s_rri_rot !extern s rn rd imm rot
&s_rrrr !extern s rd rn rm ra
&ri !extern rd imm
&r !extern rm
&ldst_rr !extern p w u rn rt rm shimm shtype
&ldst_ri !extern p w u rn rt imm
&ldst_block !extern rn i b u w list
@ -144,3 +145,12 @@ MOV_rxi 00100 ... ........ @arith_1i %s
CMP_xri 00101 ... ........ @arith_1i s=1
ADD_rri 00110 ... ........ @arith_1i %s
SUB_rri 00111 ... ........ @arith_1i %s
# Branch and exchange
@branchr .... .... . rm:4 ... &r
BX 0100 0111 0 .... 000 @branchr
BLX_r 0100 0111 1 .... 000 @branchr
BXNS 0100 0111 0 .... 100 @branchr
BLXNS 0100 0111 1 .... 100 @branchr

70
target/arm/translate.c
View File

@ -8364,7 +8364,7 @@ static bool trans_BX(DisasContext *s, arg_BX *a)
if (!ENABLE_ARCH_4T) {
return false;
}
gen_bx(s, load_reg(s, a->rm));
gen_bx_excret(s, load_reg(s, a->rm));
return true;
}
@ -8391,6 +8391,32 @@ static bool trans_BLX_r(DisasContext *s, arg_BLX_r *a)
return true;
}
/*
* BXNS/BLXNS: only exist for v8M with the security extensions,
* and always UNDEF if NonSecure. We don't implement these in
* the user-only mode either (in theory you can use them from
* Secure User mode but they are too tied in to system emulation).
*/
static bool trans_BXNS(DisasContext *s, arg_BXNS *a)
{
if (!s->v8m_secure || IS_USER_ONLY) {
unallocated_encoding(s);
} else {
gen_bxns(s, a->rm);
}
return true;
}
static bool trans_BLXNS(DisasContext *s, arg_BLXNS *a)
{
if (!s->v8m_secure || IS_USER_ONLY) {
unallocated_encoding(s);
} else {
gen_blxns(s, a->rm);
}
return true;
}
static bool trans_CLZ(DisasContext *s, arg_CLZ *a)
{
TCGv_i32 tmp;
@ -10756,49 +10782,11 @@ static void disas_thumb_insn(DisasContext *s, uint32_t insn)
}
break;
case 3:
{
/* 0b0100_0111_xxxx_xxxx
* - branch [and link] exchange thumb register
* In decodetree
*/
bool link = insn & (1 << 7);
if (insn & 3) {
goto undef;
}
if (link) {
ARCH(5);
}
if ((insn & 4)) {
/* BXNS/BLXNS: only exists for v8M with the
* security extensions, and always UNDEF if NonSecure.
* We don't implement these in the user-only mode
* either (in theory you can use them from Secure User
* mode but they are too tied in to system emulation.)
*/
if (!s->v8m_secure || IS_USER_ONLY) {
goto undef;
}
if (link) {
gen_blxns(s, rm);
} else {
gen_bxns(s, rm);
}
break;
}
/* BLX/BX */
tmp = load_reg(s, rm);
if (link) {
val = (uint32_t)s->base.pc_next | 1;
tmp2 = tcg_temp_new_i32();
tcg_gen_movi_i32(tmp2, val);
store_reg(s, 14, tmp2);
gen_bx(s, tmp);
} else {
/* Only BX works as exception-return, not BLX */
gen_bx_excret(s, tmp);
}
break;
}
goto illegal_op;
}
break;
}