> > I admit that I found this all quite difficult to read; IIUC, this is > > missing an IS_ENABLED(CONFIG_RISCV_ISA_ZACAS) check. > > I'm not sure we need the zacas check here, since we could use a toolchain > that supports zabha but not zacas, run this on a zabha/zacas platform and it > would work. One specific set-up I was concerned about is as follows: 1) hardware implements both zabha and zacas 2) toolchain supports both zabha and zacas 3) CONFIG_RISCV_ISA_ZABHA=y and CONFIG_RISCV_ISA_ZACAS=n Since CONFIG_RISCV_ISA_ZABHA=y, the first asm goto will get executed and, since the hardware implements zacas, that will result in a nop. Then the second asm goto will get executed and, since the hardware implements zabha, it will result in the j zabha. In conclusion, the amocas instruction following the zabha: label will get executed, thus violating (the semantics of) CONFIG_RISCV_ISA_ZACAS=n. IIUC, the diff I've posted previously in this thread shared a similar limitation/bug. Andrea
