Message ID | 20201116160831.31000-7-peter.maydell@linaro.org |
---|---|
State | Superseded |
Headers | show |
Series | target/arm: More v8.1M features | expand |
On 11/16/20 8:08 AM, Peter Maydell wrote: > - if (a->rt == 15 && (!a->l || a->reg != ARM_VFP_FPSCR)) { > + if (a->reg != ARM_VFP_FPSCR) { > + return false; > + } > + if (a->rt == 15 && !a->l) { Alternately, the parenthesis are just off: if ((a->rt == 15 && !a->l) || a->reg != ARM_VFP_FPSCR) Either way, Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
On Tue, 17 Nov 2020 at 19:42, Richard Henderson <richard.henderson@linaro.org> wrote: > > On 11/16/20 8:08 AM, Peter Maydell wrote: > > - if (a->rt == 15 && (!a->l || a->reg != ARM_VFP_FPSCR)) { > > + if (a->reg != ARM_VFP_FPSCR) { > > + return false; > > + } > > + if (a->rt == 15 && !a->l) { > > Alternately, the parenthesis are just off: > > if ((a->rt == 15 && !a->l) || a->reg != ARM_VFP_FPSCR) Mmm. As you've probably discovered by now, the refactoring in the subsequent patches means that this code gets moved and changed anyway; I just wanted it in this separate patch so the bugfix wasn't hidden in the refactoring. thanks -- PMM
diff --git a/target/arm/translate-vfp.c.inc b/target/arm/translate-vfp.c.inc index daf39306d04..aee60ff98b3 100644 --- a/target/arm/translate-vfp.c.inc +++ b/target/arm/translate-vfp.c.inc @@ -622,7 +622,10 @@ static bool trans_VMSR_VMRS(DisasContext *s, arg_VMSR_VMRS *a) * Accesses to R15 are UNPREDICTABLE; we choose to undef. * (FPSCR -> r15 is a special case which writes to the PSR flags.) */ - if (a->rt == 15 && (!a->l || a->reg != ARM_VFP_FPSCR)) { + if (a->reg != ARM_VFP_FPSCR) { + return false; + } + if (a->rt == 15 && !a->l) { return false; } }
For M-profile before v8.1M, the only valid register for VMSR/VMRS is the FPSCR. We have a comment that states this, but the actual logic to forbid accesses for any other register value is missing, so we would end up with A-profile style behaviour. Add the missing check. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- target/arm/translate-vfp.c.inc | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) -- 2.20.1