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cmd/objdump: new GOAMD64=v3 instructions don't disassemble properly #48584

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golang/arch
#10
@randall77

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@randall77

Build this program with GOAMD64=v3:

package main

//go:noinline
func f(x, y uint64) uint64 {
	return x &^ y
}
func main() {
	f(0, 0)
}

Disassembling with the native objdump -d, we get

 1053b20:       c4 e2 e0 f2 c0  andnq   %rax, %rbx, %rax

With go tool objdump we get

  :0                    0x1053b20               c4e2e0f2c0c3cc          ROLL $0xcc, BL          

@martisch

Side note, the popcount instruction disassembles as POPCNT, it should really disassemble as POPCNTQ or POPCNTL, as appropriate.

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    NeedsFixThe path to resolution is known, but the work has not been done.compiler/runtimeIssues related to the Go compiler and/or runtime.help wanted

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