Andi Kleen <a...@firstfloor.org> writes:
Ping^2!
> Andi Kleen <a...@firstfloor.org> writes:
>
> Ping!
>
>> From: Andi Kleen <a...@linux.intel.com>
>>
>> xbegin/xend/xabort were missing memory barriers. This can
>> lead to memory operations being moved out of transactions, which would
>> cause unexpected races.
>>
>> Always generate implicit memory barriers for these intrinsics.
>>
>> The compat header versions always generated memory barriers,
>> so this also improves compatibility.
>>
>> Passes test suite. Ok for release branches?
>>
>> gcc/:
>>
>> 2014-10-28 Andi Kleen <a...@linux.intel.com>
>>
>> PR target/63672
>> * config/i386/i386.c (ix86_expand_builtin): Generate memory
>> barrier after abort.
>> * config/i386/i386.md (xbegin): Add memory barrier.
>> (xend): Rename to ...
>> (xend_1): New. Generate memory barrier and emit xend.
>> ---
>> gcc/config/i386/i386.c | 1 +
>> gcc/config/i386/i386.md | 18 +++++++++++++++++-
>> 2 files changed, 18 insertions(+), 1 deletion(-)
>>
>> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
>> index ec3e056..ec0df40 100644
>> --- a/gcc/config/i386/i386.c
>> +++ b/gcc/config/i386/i386.c
>> @@ -36413,6 +36413,7 @@ addcarryx:
>> return const0_rtx;
>> }
>> emit_insn (gen_xabort (op0));
>> + emit_insn (gen_memory_blockage ());
>> return 0;
>>
>> default:
>> diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
>> index 7ba07c3..3544e60 100644
>> --- a/gcc/config/i386/i386.md
>> +++ b/gcc/config/i386/i386.md
>> @@ -18530,6 +18530,9 @@
>>
>> emit_move_insn (operands[0], ax_reg);
>>
>> + operands[0] = gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (Pmode));
>> + MEM_VOLATILE_P (operands[0]) = 1;
>> +
>> DONE;
>> })
>>
>> @@ -18546,13 +18549,26 @@
>> [(set_attr "type" "other")
>> (set_attr "length" "6")])
>>
>> -(define_insn "xend"
>> +(define_insn "xend_1"
>> [(unspec_volatile [(const_int 0)] UNSPECV_XEND)]
>> "TARGET_RTM"
>> "xend"
>> [(set_attr "type" "other")
>> (set_attr "length" "3")])
>>
>> +(define_expand "xend"
>> + [(set (match_dup 0)
>> + (unspec:BLK [(const_int 0)] UNSPECV_XEND))] /* or match_dup 0 ? */
>> + "TARGET_RTM"
>> +{
>> + emit_insn (gen_xend_1 ());
>> +
>> + operands[0] = gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (Pmode));
>> + MEM_VOLATILE_P (operands[0]) = 1;
>> +
>> + DONE;
>> +})
>> +
>> (define_insn "xabort"
>> [(unspec_volatile [(match_operand:SI 0 "const_0_to_255_operand" "n")]
>> UNSPECV_XABORT)]
--
a...@linux.intel.com -- Speaking for myself only
