On 2/8/21 10:28 AM, Peter Maydell wrote: > On Mon, 8 Feb 2021 at 17:53, Peter Maydell <peter.mayd...@linaro.org> wrote: >> The AAPCS says that q4-q7 are preserved across calls. > > Speaking of which, doesn't that mean we also need to > save and restore q4-q7 in tcg_target_qemu_prologue() > if we might be generating neon insns? (It doesn't look like > aarch64's prologue does this, which seems like a bug.)
I just put them on the reserved list so that they don't get used. > tcg_regset_reset_reg(tcg_target_call_clobber_regs, TCG_REG_V8); ... > tcg_regset_reset_reg(tcg_target_call_clobber_regs, TCG_REG_V15); We have way more vector registers than TCG will currently use, and we have to assume all helpers can modify env->memory, so avoiding the call-saved ones is best. r~
