cmd/compile: register ABI bringup testcase failures (tracking issue)

[thanm]

Note: this is not a regular bug, but instead tracking issue in which to collect testcases that cause failures with the new Go register ABI work.

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

$ go version
go version devel +a2f7067233 Fri Mar 5 15:34:32 2021 +0000 linux/amd64

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

linux/amd64

What did you do?

First instance:

$ git clone https://github.com/thanm/cabi-testgen
...
$ cd cabi-testgen/cabi-testgen
$ git checkout 0779299
$ go build .
$ ./cabi-testgen -q 1 -n 1 -s 1614962541 -o /tmp/cabiTest -p cabiTest -pragma registerparams
$ cd  /tmp/cabiTest
$ go build -p 1 .

What did you expect to see?

clean build

What did you see instead?

testcase.go:37:6: internal compiler error: 'Test0': not lowered: v10, StringPtr PTR STRING

goroutine 19 [running]:
runtime/debug.Stack(0xf9ecc0, 0xc0000be008, 0x0)
	/w/go/src/runtime/debug/stack.go:24 +0x9f
cmd/compile/internal/base.FatalfAt(0x2506000000002, 0xc0004b1cc8, 0x8, 0xc0003ad880, 0x2, 0x2)
	/w/go/src/cmd/compile/internal/base/print.go:227 +0x1bc
cmd/compile/internal/base.Fatalf(...)
	/w/go/src/cmd/compile/internal/base/print.go:196
cmd/compile/internal/ssagen.(*ssafn).Fatalf(0xc0003dd2f0, 0x2506000000002, 0xe4e7d2, 0x2, 0xc00009fcf0, 0x1, 0x1)
	/w/go/src/cmd/compile/internal/ssagen/ssa.go:7353 +0x1a7
cmd/compile/internal/ssa.(*Func).Fatalf(...)
	/w/go/src/cmd/compile/internal/ssa/func.go:656
cmd/compile/internal/ssa.checkLower(0xc00017dba0)
	/w/go/src/cmd/compile/internal/ssa/lower.go:41 +0x439
cmd/compile/internal/ssa.Compile(0xc00017dba0)
	/w/go/src/cmd/compile/internal/ssa/compile.go:96 +0x99e
cmd/compile/internal/ssagen.buildssa(0xc000100580, 0x0, 0x0)
	/w/go/src/cmd/compile/internal/ssagen/ssa.go:635 +0x18d2
cmd/compile/internal/ssagen.Compile(0xc000100580, 0x0)
	/w/go/src/cmd/compile/internal/ssagen/pgen.go:158 +0x5f
cmd/compile/internal/gc.compileFunctions.func2.1(0xc000124310, 0xc000100580, 0xc0000be700, 0xc0000bb5c0)
	/w/go/src/cmd/compile/internal/gc/compile.go:130 +0x65
created by cmd/compile/internal/gc.compileFunctions.func2
	/w/go/src/cmd/compile/internal/gc/compile.go:128 +0x8e

Reduced testcase attached, repro with "go tool compile -p x testcase.go".
testcase.go.txt

[thanm]

@dr2chase, @aclements , @mknyszek , @cherrymui , @jeremyfaller

[thanm]

OK, here is a second problem (different failure mode). This is on the caller side (requires two packages).

Recipe:

$ git clone https://github.com/thanm/cabi-testgen
...
$ cd cabi-testgen/cabi-testgen
$ git checkout 0779299
$ go build .
$ ./cabi-testgen -q 1 -n 1 -s 2345 -o /tmp/cabiTest -p cabiTest -pragma registerparams
$ cd  /tmp/cabiTest
$ go build -p 1 .

Failure mode:

# cabiTest/genCaller0
genCaller0/genCaller0.go:43:9: internal compiler error: 'Caller0': panic during schedule while compiling Caller0:

runtime error: index out of range [10] with length 9

goroutine 8 [running]:
cmd/compile/internal/ssa.Compile.func1(0xc000558cf8, 0xc00007e340)
	/w/go/src/cmd/compile/internal/ssa/compile.go:48 +0xa5
panic(0xe105a0, 0xc0000e86c0)
	/w/go/src/runtime/panic.go:972 +0x1d4
cmd/compile/internal/ssa.schedule(0xc00007e340)
	/w/go/src/cmd/compile/internal/ssa/schedule.go:277 +0x235c
cmd/compile/internal/ssa.Compile(0xc00007e340)
	/w/go/src/cmd/compile/internal/ssa/compile.go:96 +0x99e
cmd/compile/internal/ssagen.buildssa(0xc0001022c0, 0x0, 0x0)
	/w/go/src/cmd/compile/internal/ssagen/ssa.go:635 +0x18d2
cmd/compile/internal/ssagen.Compile(0xc0001022c0, 0x0)
	/w/go/src/cmd/compile/internal/ssagen/pgen.go:158 +0x5f
cmd/compile/internal/gc.compileFunctions.func2.1(0xc0000b8000, 0xc0001022c0, 0xc0000be088, 0xc0000ba1a0)
	/w/go/src/cmd/compile/internal/gc/compile.go:130 +0x65
created by cmd/compile/internal/gc.compileFunctions.func2
	/w/go/src/cmd/compile/internal/gc/compile.go:128 +0x8e

To reproduce, download the cabiTest.zip file, then

$ unzip cabiTest.zip
$ cd cabiTest
$ go build -p 1 .

cabiTest.zip

[mknyszek]

The following program fails to compile at tip (with GOEXPERIMENT=regabi set during ./make.bash of course):

package main

import "fmt"

//go:registerparams
//go:noinline
func passStruct6(a Struct6) Struct6 {
        return a
}

type Struct6 struct {
        Struct1
}

type Struct1 struct {
        A, B, C uint
}

func main() {
        fmt.Println(passStruct6(Struct6{Struct1{1, 2, 3}}))
}

Output:

$ ~/toolchain/bin/go run error.go
# command-line-arguments
./error.go:8:2: internal compiler error: 'passStruct6': not lowered: v4, StructSelect UINT STRUCT

goroutine 14 [running]:
runtime/debug.Stack(0xf7e1e0, 0xc00000e018, 0x0)
        /usr/local/google/home/mknyszek/toolchain/src/runtime/debug/stack.go:24 +0x94
cmd/compile/internal/base.FatalfAt(0x802100000002, 0xc0005d3cc8, 0x8, 0xc0004812e0, 0x2, 0x2)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/base/print.go:227 +0x1ac
cmd/compile/internal/base.Fatalf(...)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/base/print.go:196
cmd/compile/internal/ssagen.(*ssafn).Fatalf(0xc00010a3c0, 0x802100000002, 0xe2da72, 0x2, 0xc0000acf60, 0x1, 0x1)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssagen/ssa.go:7353 +0x195
cmd/compile/internal/ssa.(*Func).Fatalf(...)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssa/func.go:656
cmd/compile/internal/ssa.checkLower(0xc0003f81a0)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssa/lower.go:41 +0x3fa
cmd/compile/internal/ssa.Compile(0xc0003f81a0)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssa/compile.go:96 +0x98d
cmd/compile/internal/ssagen.buildssa(0xc0003d4160, 0x0, 0x0)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssagen/ssa.go:635 +0x1892
cmd/compile/internal/ssagen.Compile(0xc0003d4160, 0x0)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssagen/pgen.go:158 +0x52
cmd/compile/internal/gc.compileFunctions.func2.1(0xc0003f0080, 0xc0003d4160, 0xc0000a24e8, 0xc0003dd010)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/gc/compile.go:130 +0x56
created by cmd/compile/internal/gc.compileFunctions.func2
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/gc/compile.go:128 +0x85

[mknyszek]

Another ICE at tip:

package main

import "fmt"

//go:registerparams
//go:noinline
func passStruct8(a Struct8) Struct8 {
        return a
}

type Struct8 struct {
        Struct5
        Struct1
}

type Struct1 struct {
        A, B, C uint
}

type Struct5 struct {
        A             uint16
        B             int16
        C, D          uint32
        E             int32
        F, G, H, I, J float32
}

func main() {
        fmt.Println(passStruct8(Struct8{
                Struct5{1, 2, 3, 4, 5, 1.0, 2.0, 3.0, 4.0, 5.0},
                Struct1{1, 2, 3},
        }))
}

Output:

# command-line-arguments                                                                                                                                                                                    
./error2.go:33:1: internal compiler error: 'main': panic during regalloc while compiling main:                                                                                                              
                                                                                                                                                                                                            
nil v, s.orig[8], vi = {0 <nil> 0xc0006d0518 2 5 false false}, spill = v103 = StoreReg <mem>                                                                                                                
                                                                                                                                                                                                            
goroutine 9 [running]:                        
cmd/compile/internal/ssa.Compile.func1(0xc0004bccf8, 0xc0000a4000)                                 
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssa/compile.go:48 +0x9c
panic(0xd9d380, 0xc000068330)                                                                         
        /usr/local/google/home/mknyszek/toolchain/src/runtime/panic.go:972 +0x1c5
cmd/compile/internal/ssa.(*regAllocState).placeSpills(0xc000082480)                                
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssa/regalloc.go:1816 +0xed8  
cmd/compile/internal/ssa.(*regAllocState).regalloc(0xc000082480, 0xc0000a4000)                    
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssa/regalloc.go:1730 +0x73e6
cmd/compile/internal/ssa.regalloc(0xc0000a4000)                                                       
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssa/regalloc.go:147 +0x5d
cmd/compile/internal/ssa.Compile(0xc0000a4000)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssa/compile.go:96 +0x98d
cmd/compile/internal/ssagen.buildssa(0xc0001042c0, 0x1, 0x0)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssagen/ssa.go:635 +0x1892
cmd/compile/internal/ssagen.Compile(0xc0001042c0, 0x1)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssagen/pgen.go:158 +0x52
cmd/compile/internal/gc.compileFunctions.func2.1(0xc000030100, 0xc0001042c0, 0xc0000ba700, 0xc0000b72b0)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/gc/compile.go:130 +0x56
created by cmd/compile/internal/gc.compileFunctions.func2
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/gc/compile.go:128 +0x85



goroutine 9 [running]:
runtime/debug.Stack(0xf7e1e0, 0xc0000ba008, 0x0)
        /usr/local/google/home/mknyszek/toolchain/src/runtime/debug/stack.go:24 +0x94
cmd/compile/internal/base.FatalfAt(0x2101000000002, 0xc00043a3c0, 0x32, 0xc000490500, 0x5, 0x5)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/base/print.go:227 +0x1ac
cmd/compile/internal/base.Fatalf(...)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/base/print.go:196
cmd/compile/internal/ssagen.(*ssafn).Fatalf(0xc00061c600, 0x2101000000002, 0xe55822, 0x2c, 0xc000420740, 0x4, 0x4)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssagen/ssa.go:7353 +0x195
cmd/compile/internal/ssa.(*Func).Fatalf(...)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssa/func.go:656
cmd/compile/internal/ssa.Compile.func1(0xc0004bccf8, 0xc0000a4000)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssa/compile.go:53 +0x225
panic(0xd9d380, 0xc000068330)
        /usr/local/google/home/mknyszek/toolchain/src/runtime/panic.go:972 +0x1c5
cmd/compile/internal/ssa.(*regAllocState).placeSpills(0xc000082480)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssa/regalloc.go:1816 +0xed8 
cmd/compile/internal/ssa.(*regAllocState).regalloc(0xc000082480, 0xc0000a4000)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssa/regalloc.go:1730 +0x73e6
cmd/compile/internal/ssa.regalloc(0xc0000a4000)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssa/regalloc.go:147 +0x5d
cmd/compile/internal/ssa.Compile(0xc0000a4000)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssa/compile.go:96 +0x98d
cmd/compile/internal/ssagen.buildssa(0xc0001042c0, 0x1, 0x0)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssagen/ssa.go:635 +0x1892
cmd/compile/internal/ssagen.Compile(0xc0001042c0, 0x1)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/ssagen/pgen.go:158 +0x52
cmd/compile/internal/gc.compileFunctions.func2.1(0xc000030100, 0xc0001042c0, 0xc0000ba700, 0xc0000b72b0)
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/gc/compile.go:130 +0x56
created by cmd/compile/internal/gc.compileFunctions.func2
        /usr/local/google/home/mknyszek/toolchain/src/cmd/compile/internal/gc/compile.go:128 +0x85

[mknyszek]

I don't know what I changed, but now when I run that last test case I get

tmp $ ~/toolchain/bin/go run error2.go
# command-line-arguments
<autogenerated>:1: invalid instruction: 00022 (/usr/local/google/home/mknyszek/tmp/error2.go:7) MOVUPS  R8, X5
<autogenerated>:1: invalid instruction: 00028 (/usr/local/google/home/mknyszek/tmp/error2.go:7) MOVUPS  R9, X5
<autogenerated>:1: invalid instruction: 00034 (/usr/local/google/home/mknyszek/tmp/error2.go:7) MOVUPS  R10, X5
<autogenerated>:1: invalid instruction: 00228 (/usr/local/google/home/mknyszek/tmp/error2.go:8) MOVUPS  X5, R8
<autogenerated>:1: invalid instruction: 00228 (/usr/local/google/home/mknyszek/tmp/error2.go:8) MOVUPS  X6, R9
<autogenerated>:1: invalid instruction: 00228 (/usr/local/google/home/mknyszek/tmp/error2.go:8) MOVUPS  X7, R10

[gopherbot]

Change https://golang.org/cl/299389 mentions this issue: cmd/compile: fix OpArg decomposer for registers in expandCalls

[dr2chase]

@mknyszek
Welcome to the land of concurrent compilation, it seemed like a good idea at the time. Your test shows two bugs.
Try

GOMAXPROCS=1 GOSSADIR=`pwd` GOSSAFUNC=passStruct8 go build -p 1 -gcflags='-c=1' mk.go

to see one of them more repeatably.

[gopherbot]

Change https://golang.org/cl/299409 mentions this issue: cmd/compile: fix broken type+offset calc for register args

[gopherbot]

Change https://golang.org/cl/299549 mentions this issue: cmd/compile: fix confusion in generating SelectN index

[dr2chase]

Smaller (edited) reproducer of the "invalid instruction" failures:

package main

import "fmt"

type P struct {
        a int8
        x float64
}

type T struct {
        d,e P
}

//go:registerparams
//go:noinline
func G(t T) float64 {
        return float64(t.d.a + t.e.a)+t.d.x+t.e.x
}

func main() {
        fmt.Println(G(T{P{10,20},P{30,40}}))
}

yields

go build mk.go
# command-line-arguments
<autogenerated>:1: cursym="".main, invalid instruction: 00034 (/Users/drchase/work/tmp/abi/mk.go:22)	MOVSD	$f64.4034000000000000(SB), BX
<autogenerated>:1: cursym="".main, invalid instruction: 00034 (/Users/drchase/work/tmp/abi/mk.go:22)	MOVL	$30, X0
<autogenerated>:1: cursym="".G, invalid instruction: 00017 (/Users/drchase/work/tmp/abi/mk.go:17)	MOVUPS	BX, X2

Says "autogenerated", but appears in the compilation output (v8), must be an artifact of the assembler reporting. I modified the diagnostic printer to be clear about what's being compiled.

# /Users/drchase/work/tmp/abi/mk.go
	00000 (16) TEXT "".G(SB), ABIInternal
	00001 (16) FUNCDATA $0, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
	00002 (16) FUNCDATA $1, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)
v7	00003 (+17) MOVL X0, CX
v13	00004 (17) ADDL CX, AX
v14	00005 (17) MOVBQSX AX, AX
v15	00006 (17) XORPS X0, X0
v15	00007 (17) CVTSL2SD AX, X0
v8	00008 (17) MOVUPS BX, X2
v18	00009 (17) ADDSD X2, X0
v21	00010 (17) ADDSD X1, X0
b1	00011 (17) RET
	00012 (?) END

[dr2chase]

Found it. I thought that abiutils would render the parameter registers I0, F0, I1, F1 -- in the order that the parameters use them -- and instead it does them I0, I1, F0, F1. Oops.

[gopherbot]

Change https://golang.org/cl/299570 mentions this issue: cmd/compile: fix failure to communicate between ABIinfo producer&consumer

[gopherbot]

Change https://golang.org/cl/299410 mentions this issue: cmd/compile: test register ABI for method, interface, closure calls