The accurate dot products went to the IR interpreter, flushing everything around each one. Now
the JIT stores the operands to mips->vfpuDotArgs and calls a routine generated at startup, which
clobbers only registers late in the allocation order. Inf and NaN go to vfpu_dot_reference().
The routine is vfpu_dot_scalar() in RV64, using Zbb and Zicond where it has them, or with the V
extension, vfpu_dot_sse2() in RVV. The rounding at the end comes from FCVT.S.LU with a static
round-to-nearest-even, which also gives the exponent, so there's no need for Zbb's CLZ.
VFPUDotJit runs each variant the host can run against the reference on VFPUDot's inputs, the RVV
one with poisoned vector registers. PPSSPP_CPUFUZZ_HOSTEXT=- now turns V off too.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
