On 09.10.2011 00:57, Peter Maydell wrote:
On 3 October 2011 15:28, Christophe Lyon<christophe.l...@st.com> wrote:Indeed, the result is known to be always positive. - val = ((val64>> 63)& 0x80000000) - | ((result_exp& 0xff)<< 23) + val = ((result_exp& 0xff)<< 23) | ((val64>> 29)& 0x7fffff); return make_float32(val);So we weren't generating incorrect results, we were just doing slightly more work than we really needed, right? I'm curious what prompted this patch :-)
Exactly. And no way to expose a bug :-( I was reading 2 revisions of the ARM ARM, and noticed erratas in the descriptions of FPRecipEstimate and FPRSqrtEstimate. Sign propagation has been removed in the former, and not in the later, so I re-read both functions carefully as well as qemu's implementation and came to this conclusion :-) I have contacted ARM support and suggested them to fix both function accordingly :-) Christophe.
