Re: [Qemu-devel] [PATCH 3/5] target-arm: convert shl and shr helpers to TCG

[Richard Henderson]

On 09/17/2012 02:43 AM, Peter Maydell wrote:
> The TCG shift operations are undefined behaviour (not merely
> undefined result) if the shift is >= 32, so we must avoid
> doing that even if we're going to throw away the answer.

I don't think that ought to be true.

In particular, I've just posted a patch to cure the Sparc TCG
backend from producing an illegal insn in the face of a shift
with a count of 64.

I'd much rather we simply had an undefined result.


r~