cmd/compile: sign extension wrong for paired 32-bit loads on arm64

[randall77]

package main

//go:noinline                                                                                                                                                                            
func f(p *[2]int32) (int64, int64) {
        return int64(p[0]), int64(p[1])
}

func main() {
	p := [2]int32{-1, -1}
	x, y :=	f(&p)
	println(x, y)
}

Should print -1 -1. At tip it produces 4294967295 4294967295.

This is a bug in the recent CL 629256.

[gopherbot]

Change https://go.dev/cl/649895 mentions this issue: cmd/compile: fix sign extension of paired 32-bit loads on arm64

[gabyhelp]

Related Code Changes

• cmd/compile: fix sign extension of paired 32-bit loads on arm64

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