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

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randall77 opened this issue Sep 23, 2021 · 1 comment
Open

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

randall77 opened this issue Sep 23, 2021 · 1 comment
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compiler/runtime Issues related to the Go compiler and/or runtime. help wanted NeedsFix The path to resolution is known, but the work has not been done.
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Backlog

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@randall77
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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.
@gopherbot
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Change https://golang.org/cl/351889 mentions this issue: x86asm: include size suffix on popcnt instruction

gopherbot pushed a commit to golang/arch that referenced this issue Sep 23, 2021
@randall77
x86asm: include size suffix on popcnt instruction
b76863e 
Update golang/go#48584

Change-Id: I2c770aaf88e15f8987dc8f1d974127b02b220777
Reviewed-on: https://go-review.googlesource.com/c/arch/+/351889
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
@dr2chase dr2chase added the NeedsFix The path to resolution is known, but the work has not been done. label Sep 24, 2021
@gopherbot gopherbot added the compiler/runtime Issues related to the Go compiler and/or runtime. label Jul 13, 2022
@seankhliao seankhliao added this to the Backlog milestone Aug 20, 2022
@wdvxdr1123 wdvxdr1123 mentioned this issue Sep 14, 2022
Closed
AppleSeed95 pushed a commit to AppleSeed95/arch that referenced this issue Feb 2, 2024
@randall77
x86asm: include size suffix on popcnt instruction
81d4328 
Update golang/go#48584

Change-Id: I2c770aaf88e15f8987dc8f1d974127b02b220777
Reviewed-on: https://go-review.googlesource.com/c/arch/+/351889
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
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compiler/runtime Issues related to the Go compiler and/or runtime. help wanted NeedsFix The path to resolution is known, but the work has not been done.
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Go Compiler / Runtime
Status: Triage Backlog
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@dr2chase @randall77 @gopherbot @seankhliao