On 11/19/20 8:35 PM, Maciej W. Rozycki wrote:
> Remove an ICE like:
>
> during RTL pass: expand
> .../libatomic/tas_n.c: In function 'libat_test_and_set_1':
> .../libatomic/tas_n.c:39:1: internal compiler error: in patch_jump_insn, at
> cfgrtl.c:1298
> 39 | }
> | ^
> 0x108a09ff patch_jump_insn
> .../gcc/cfgrtl.c:1298
> 0x108a0b07 redirect_branch_edge
> .../gcc/cfgrtl.c:1325
> 0x108a124b rtl_redirect_edge_and_branch
> .../gcc/cfgrtl.c:1458
> 0x1087f6d3 redirect_edge_and_branch(edge_def*, basic_block_def*)
> .../gcc/cfghooks.c:373
> 0x11d6264b try_forward_edges
> .../gcc/cfgcleanup.c:562
> 0x11d6b0eb try_optimize_cfg
> .../gcc/cfgcleanup.c:2960
> 0x11d6ba4f cleanup_cfg(int)
> .../gcc/cfgcleanup.c:3174
> 0x10870b3f execute
> .../gcc/cfgexpand.c:6763
>
> triggered with an RTL pattern like:
>
> (jump_insn 8 7 20 2 (parallel [
> (set (pc)
> (if_then_else (ne (zero_extract:SI (mem/v:QI (mem/f/c:SI
> (reg/f:SI 16 virtual-incoming-args) [1 mptr+0 S4 A32]) [-1 S1 A8])
> (const_int 1 [0x1])
> (const_int 0 [0]))
> (const_int 0 [0]))
> (label_ref 10)
> (pc)))
> (set (zero_extract:SI (mem/v:QI (mem/f/c:SI (reg/f:SI 16
> virtual-incoming-args) [1 mptr+0 S4 A32]) [-1 S1 A8])
> (const_int 1 [0x1])
> (const_int 0 [0]))
> (const_int 1 [0x1]))
> ]) ".../libatomic/tas_n.c":38:12 -1
> (nil)
> -> 10)
>
> caused by a volatile memory reference used that is not accepted by the
> `memory_operand' predicate of the `jbbssiqi' insn explicitly referred
> from the `sync_lock_test_and_setqi' expander. Also seen with:
>
> FAIL: gcc.dg/pr61756.c (internal compiler error)
>
> Define a new `any_memory_operand' predicate accepting both ordinary and
> volatile memory references and use it with the `jbb<ccss>i<mode>' insn,
> so as to address the ICE.
>
> Also remove useless operations from the `sync_lock_test_and_set<mode>'
> and `sync_lock_release<mode>' expanders as those always either complete
> or fail and therefore never fall through to using their template other
> than to match operands. Wrap `jbb<ccss>i<mode>' into `unspec_volatile'
> instead so that the jump does not get removed or reordered. Share one
> index to avoid a complication around the iterators since the index is
> nowhere referred to anyway and the pattern required pulled by its name.
>
> Test cases will be added separately.
>
> gcc/
> * config/vax/predicates.md (volatile_mem_operand)
> (any_memory_operand): New predicates.
> * config/vax/builtins.md (VUNSPEC_UNLOCK): Remove constant.
> (sync_lock_test_and_set<mode>): Remove `set' and `unspec'
> operations, match operands only. Reformat.
> (sync_lock_release<mode>): Likewise. Remove cruft.
> (jbb<ccss>i<mode>): Wrap into `unspec_volatile', use
> `any_memory_operand' predicate.
OK
jeff
