ARM/Neon: vcvt rounding error

Hello,

While using QEMU commit 47d3b60858d90ac8a0cc3a72af7f95c96781125a (March 28, 2018), I've noticed failures in one of the GCC ARM/Neon tests. The test passes on hardware, and with QEMU-2.11.0, so it looks like a recent regression.

The test builds a vector of 4 float32 with "125.9" as value, then converts them to 4 uint32_t.
The expected result is 125, but we get 126 instead.

Maybe it's just a matter of default rounding mode?

Hi Christophe -- we think that commit bd49e6027cbc207c, now in master, should have fixed this bug. Could you retry your testcase with a QEMU build including that fix?


I updated my QEMU git tree such that it includes commit bd49e6027cbc207c, and the test now passes.

Thanks for the prompt fix!