runtime: floating-point comparison error on Loong64

[yelvens]

What version of Go are you using (go version)?

$ go version
go version devel go1.21-f5c7416511 Thu Mar 9 22:13:26 2023 +0000 linux/loong64

Does this issue reproduce with the latest release?

What operating system and processor architecture are you using (go env)?

go env Output

$ go env

What did you do?

package main

import(
        "fmt"
)

func main() {
        var target float64 = 100000.0
        for i := 1; i < 100000000; i++ {
                var fslice []float64
                for j := 0; j < 100; j++ {
                        fslice = append(fslice, 1.124567)
                }
                var sum float64
                for _, f := range fslice {
                        sum += f
                        sum += 0.1 
                        sum += 0.2 
                        sum += 0.3 
                        if sum >= target {
                                fmt.Println("err 1")
                        }
                        if sum >= target {
                                fmt.Println("err 2")
                        }
                        if sum >= target {
                                fmt.Println("err 3")
                        }
                        if sum >= target {
                                if sum < target {
                                        fmt.Println("err 4")
                                }
                        }
                }
        }
}

What did you expect to see?

(i.e. no output)

What did you see instead?

err 3
err 4
err 2
...

(i.e. numbers are unordered)

[gopherbot]

Change https://go.dev/cl/475577 mentions this issue: runtime: save and restore fcc registers in async preempt on loong64

[mknyszek]

CC @golang/loong64

[xen0n]

Commit 48d61a4 had the "Fixes" keyword misspelled, so the issue was not auto-closed.

Manually closing as completed.