[Bug target/121652] [15/16 Regression] round builtin does not raise FE_INVALID for signaling NaN

[xry111 at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121652

--- Comment #2 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
The easiest way would be a feq.[sd] with the operand as both inputs, and r0 as
the output:

"FEQ.S performs a quiet comparison: it only sets the invalid operation
exception flag if either input is a signaling NaN."