cmd/compile: negate comparision with FNES/FNED on riscv64
The FNES and FNED instructions are pseudo-instructions, which the
assembler expands to FEQS/NEG or FEQD/NEG - if we're comparing the
result via a branch instruction, we can avoid an instruction by
negating both the branch comparision and the floating point
comparision.
This only removes a handful of instructions from the Go binary,
however, it will provide benefit to floating point intensive code.
Change-Id: I4e3124440b7659acc4d9bc9948b755a4900a422f
Reviewed-on: https://go-review.googlesource.com/c/go/+/426261 Reviewed-by: Meng Zhuo <mzh@golangcn.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Joel Sing <joel@sing.id.au>
Run-TryBot: Meng Zhuo <mzh@golangcn.org> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Heschi Kreinick <heschi@google.com>