Re: [Qemu-devel] [PATCH 04/15] target/arm: Tighten up Thumb decode where new v8M insns will be

2017-08-03 Thread Richard Henderson
On 08/02/2017 09:43 AM, Peter Maydell wrote: > Tighten up the T32 decoder in the places where new v8M instructions > will be: > * TT/TTT/TTA/TTAT are in what was nominally LDREX/STREX r15, ... >which is UNPREDICTABLE: >make the UNPREDICTABLE behaviour be to UNDEF > * BXNS/BLXNS are

[Qemu-devel] [PATCH 04/15] target/arm: Tighten up Thumb decode where new v8M insns will be

2017-08-02 Thread Peter Maydell
Tighten up the T32 decoder in the places where new v8M instructions will be: * TT/TTT/TTA/TTAT are in what was nominally LDREX/STREX r15, ... which is UNPREDICTABLE: make the UNPREDICTABLE behaviour be to UNDEF * BXNS/BLXNS are distinguished from BX/BLX via the low 3 bits, which in