runtime: fatal error: unknown caller pc

[mdempsky]

This program should run successfully: https://play.golang.org/p/LQbgPxRijfF

But currently it fails when run with cmd/compile with output:

Full runtime output

runtime: unexpected return pc for main.main.func2.1 called from 0xc00005c0a0
stack: frame={sp:0xc000066ed0, fp:0xc000066ef0} stack=[0xc000066000,0xc000067000)
000000c000066dd0:  00000000004b27a0  000000000055fac8 
000000c000066de0:  000000c000066f00  0000000000000000 
000000c000066df0:  0000000000000000  0000000000000000 
000000c000066e00:  000000c000066e40  00000000004a6fe5 <main.main.func3.1+133> 
000000c000066e10:  00000000004b27a0  000000000055fac8 
000000c000066e20:  0000000000000000  00000000004d4580 
000000c000066e30:  00000000004b27a0  000000000055fac8 
000000c000066e40:  000000c000066e70  000000000046203e <runtime.call32+62> 
000000c000066e50:  00000000004a7075 <main.main.func3+85>  000000c000066f48 
000000c000066e60:  000000c000000180  0000000000000000 
000000c000066e70:  000000c000066f38  000000000043233a <runtime.gopanic+1146> 
000000c000066e80:  0000000000000000  00000000004d4358 
000000c000066e90:  0000000000000000  0000000000000000 
000000c000066ea0:  00000000004ea968  00000000004b8a01 
000000c000066eb0:  00000000004d4340  00000000004d4338 
000000c000066ec0:  000000c00005c0a0  00000000004a6e05 <main.main.func2.1+69> 
000000c000066ed0: <000000c000000180  00000000004d4348 
000000c000066ee0:  000000c00005c0c0 !000000c00005c0a0 
000000c000066ef0: >000000c0000001a8  000000c0000001a0 
000000c000066f00:  000000c000066e50  00000000004b27a0 
000000c000066f10:  00000000004ea970  0000000000000000 
000000c000066f20:  0000000000000000  0000000000000000 
000000c000066f30:  0000000000000100  000000c000066f58 
000000c000066f40:  00000000004a7075 <main.main.func3+85>  00000000004b27a0 
000000c000066f50:  00000000004ea970  000000c000066f78 
000000c000066f60:  00000000004a694a <main.main+74>  01000000004b2260 
000000c000066f70:  00000000004d4328  000000c000066fd0 
000000c000066f80:  0000000000435029 <runtime.main+521>  000000c00005e000 
000000c000066f90:  0000000000000000  000000c00005e000 
000000c000066fa0:  0000000000000000  0100000000000000 
000000c000066fb0:  0000000000000000  000000c000000180 
000000c000066fc0:  000000c000066fae  00000000004d45c0 
000000c000066fd0:  0000000000000000  00000000004638c1 <runtime.goexit+1> 
000000c000066fe0:  0000000000000000  0000000000000000 
fatal error: unknown caller pc

runtime stack:
runtime.throw(0x4ce407, 0x11)
	/usr/local/go-faketime/src/runtime/panic.go:1116 +0x72
runtime.gentraceback(0x4a6e05, 0xc000066ed0, 0x0, 0xc000000180, 0x0, 0x0, 0x7fffffff, 0x7f1916469db8, 0x0, 0x0, ...)
	/usr/local/go-faketime/src/runtime/traceback.go:273 +0x1aec
runtime.addOneOpenDeferFrame.func1()
	/usr/local/go-faketime/src/runtime/panic.go:721 +0x91
runtime.systemstack(0x461b54)
	/usr/local/go-faketime/src/runtime/asm_amd64.s:370 +0x66
runtime.mstart()
	/usr/local/go-faketime/src/runtime/proc.go:1116

goroutine 1 [running]:
runtime.systemstack_switch()
	/usr/local/go-faketime/src/runtime/asm_amd64.s:330 fp=0xc000066d08 sp=0xc000066d00 pc=0x461c80
runtime.addOneOpenDeferFrame(0xc000000180, 0x0, 0x0)
	/usr/local/go-faketime/src/runtime/panic.go:720 +0x7b fp=0xc000066d48 sp=0xc000066d08 pc=0x4318db
panic(0x4b27a0, 0x55fac8)
	/usr/local/go-faketime/src/runtime/panic.go:971 +0x417 fp=0xc000066e10 sp=0xc000066d48 pc=0x4322d7
main.main.func3.1()
	/tmp/sandbox276749924/prog.go:31 +0x85 fp=0xc000066e50 sp=0xc000066e10 pc=0x4a6fe5
runtime.call32(0x0, 0x4d4358, 0x0, 0x0)
	/usr/local/go-faketime/src/runtime/asm_amd64.s:540 +0x3e fp=0xc000066e80 sp=0xc000066e50 pc=0x46203e
panic(0x4b27a0, 0x4ea970)
	/usr/local/go-faketime/src/runtime/panic.go:975 +0x47a fp=0xc000066f48 sp=0xc000066e80 pc=0x43233a
main.main.func3()
	/tmp/sandbox276749924/prog.go:34 +0x55 fp=0xc000066f68 sp=0xc000066f48 pc=0x4a7075
main.main()
	/tmp/sandbox276749924/prog.go:35 +0x4a fp=0xc000066f88 sp=0xc000066f68 pc=0x4a694a
runtime.main()
	/usr/local/go-faketime/src/runtime/proc.go:204 +0x209 fp=0xc000066fe0 sp=0xc000066f88 pc=0x435029
runtime.goexit()
	/usr/local/go-faketime/src/runtime/asm_amd64.s:1374 +0x1 fp=0xc000066fe8 sp=0xc000066fe0 pc=0x4638c1

It succeeds with gccgo and cmd/compile w/ -gcflags=-N. It also still fails at CL 286712, PS 3.

Sorry for another larger reproducer.

/cc @danscales @randall77