https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104031
--- Comment #4 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
Great test, Andrew!
Something is completely dropped initialization of Info{} input argument to
s_op. As if it's lifetime ends before RegisterPrimOp{} enters:
--- main.s.good 2022-01-14 21:53:42.334571321 +0000
+++ main.s.bad 2022-01-14 21:53:51.275722971 +0000
@@ -43,26 +43,25 @@
.p2align 4
.type _GLOBAL__sub_I_main, @function
_GLOBAL__sub_I_main:
.LFB14:
.cfi_startproc
subq $24, %rsp #,
.cfi_def_cfa_offset 32
# ../main.cc:21: });
movl $_ZL4s_op, %edi #,
leaq 8(%rsp), %rsi #, tmp84
- movl $0, 12(%rsp) #, D.2496.arityD.2380
call _ZN14RegisterPrimOpC1E4Info #
# ../main.cc:22: int main() {}
addq $24, %rsp #,
.cfi_def_cfa_offset 8
ret
.cfi_endproc
.LFE14:
.size _GLOBAL__sub_I_main, .-_GLOBAL__sub_I_main
.section .init_array,"aw"
.align 8
.quad _GLOBAL__sub_I_main
.local _ZL4s_op
.comm _ZL4s_op,1,1
- .ident "GCC: (GNU) 11.2.0"
+ .ident "GCC: (GNU) 12.0.0 20220109 (experimental)"
.section .note.GNU-stack,"",@progbits
Initial gimple looks valid to me: main.cc.006t.gimple:
void __static_initialization_and_destruction_0 (int __initialize_p, int
__priority)
{
struct InfoD.2399 D.2453 = {.arityD.2402=0};
...
_ZN6vectorC1EvD.2377 (&D.2453.argsD.2401);
...
try { try { try {
# USE = anything
# CLB = anything
_ZN14RegisterPrimOpC1E4InfoD.2413 (&s_opD.2424, &D.2453);
} finally {
# USE = anything
# CLB = anything
_ZN4InfoD1EvD.2457 (&D.2453);
} } finally {
D.2453 = {CLOBBER};
}
Final tree also looks ok: main.cc.250t.optimized:
voidD.48 _GLOBAL__sub_I_mainD.2486 ()
{
struct InfoD.2399 D.2522 = {.arityD.2402=0};
# USE = nonlocal escaped { D.2424 D.2522 } (nonlocal, escaped)
# CLB = nonlocal escaped { D.2424 D.2522 } (nonlocal, escaped)
_ZN14RegisterPrimOpC1E4InfoD.2413 (&_ZL4s_opD.2424, &D.2522);
D.2522 ={v} {CLOBBER};
First RTL seems to lack the assignment: main.cc.252r.expand:
;; Function _GLOBAL__sub_I_main (_GLOBAL__sub_I_main, funcdef_no=14,
decl_uid=2486, cgraph_uid=15, symbol_order=15) (executed once)
...
;;
;; Full RTL generated for this function:
;;
1: NOTE_INSN_DELETED
3: NOTE_INSN_BASIC_BLOCK 2
2: NOTE_INSN_FUNCTION_BEG
5: {r82:DI=r77:DI-0x8;clobber flags:CC;}
6: si:DI=r82:DI
7: di:DI=`_ZL4s_op'
8: call [`_ZN14RegisterPrimOpC1E4Info'] argc:0
REG_CALL_DECL `_ZN14RegisterPrimOpC1E4Info'
REG_EH_REGION 0
