Commit d46ad79e authored by Richard Henderson's avatar Richard Henderson Committed by Peter Maydell
Browse files

target/arm: Relax r13 restriction for ldrex/strex for v8.0 



Armv8-A removes UNPREDICTABLE for R13 for these cases.

Signed-off-by: default avatarRichard Henderson <richard.henderson@linaro.org>
Message-id: 20191117090621.32425-3-richard.henderson@linaro.org
[PMM: changed ENABLE_ARCH_8 checks to check a new bool 'v8a',
 since these cases are still UNPREDICTABLE for v8M]
Reviewed-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent 655b0264

target/arm/translate.c

+8 −4
Original line number Diff line number Diff line
@@ -8927,15 +8927,17 @@ static bool trans_SWPB(DisasContext *s, arg_SWP *a) 
static bool op_strex(DisasContext *s, arg_STREX *a, MemOp mop, bool rel)

{

    TCGv_i32 addr;

    /* Some cases stopped being UNPREDICTABLE in v8A (but not v8M) */

    bool v8a = ENABLE_ARCH_8 && !arm_dc_feature(s, ARM_FEATURE_M);



    /* We UNDEF for these UNPREDICTABLE cases.  */

    if (a->rd == 15 || a->rn == 15 || a->rt == 15

        || a->rd == a->rn || a->rd == a->rt

        || (s->thumb && (a->rd == 13 || a->rt == 13))

        || (!v8a && s->thumb && (a->rd == 13 || a->rt == 13))

        || (mop == MO_64

            && (a->rt2 == 15

                || a->rd == a->rt2

                || (s->thumb && a->rt2 == 13)))) {

                || (!v8a && s->thumb && a->rt2 == 13)))) {

        unallocated_encoding(s);

        return true;

    }
@@ -9084,13 +9086,15 @@ static bool trans_STLH(DisasContext *s, arg_STL *a) 
static bool op_ldrex(DisasContext *s, arg_LDREX *a, MemOp mop, bool acq)

{

    TCGv_i32 addr;

    /* Some cases stopped being UNPREDICTABLE in v8A (but not v8M) */

    bool v8a = ENABLE_ARCH_8 && !arm_dc_feature(s, ARM_FEATURE_M);



    /* We UNDEF for these UNPREDICTABLE cases.  */

    if (a->rn == 15 || a->rt == 15

        || (s->thumb && a->rt == 13)

        || (!v8a && s->thumb && a->rt == 13)

        || (mop == MO_64

            && (a->rt2 == 15 || a->rt == a->rt2

                || (s->thumb && a->rt2 == 13)))) {

                || (!v8a && s->thumb && a->rt2 == 13)))) {

        unallocated_encoding(s);

        return true;

    }