When switched to the MI scheduler for P9, the hardware is modeled as out of order.
However, inside the MI Scheduler algorithm, we still use the in-order scheduling model
as the MicroOpBufferSize isn't set. The MI scheduler take it as the hw cannot buffer
the op. So, only when all the available instructions issued, the pending instruction
could be scheduled. That is not true for our P9 hw in fact.
This patch is trying to enable the Out-of-Order scheduling model. The buffer size 44 is
picked from the P9 hw spec, and the perf test indicate that, its value won't hurt the cpu2017.
With this patch, there are 3 specs improved over 3% and 1 spec deg over 3%. The detail is as follows:
x264_r: +6.95%
cactuBSSN_r: +6.94%
lbm_r: +4.11%
xz_r: -3.85%
And the GEOMEAN for all the C/C++ spec in spec2017 is about 0.18% improved.
Reviewer: Nemanjai
Differential Revision: https://reviews.llvm.org/D55810
llvm-svn: 350285
Fix assert about using an undefined physical register in machine instruction verify pass.
The reason is that register flag undef is missing when doing transformation from If Conversion Pass.
```
Bad machine code: Using an undefined physical register
- function: func_65
- basic block: %bb.0 entry (0x10024740738)
- instruction: BCLR killed $cr5lt, implicit $lr8, implicit $rm, implicit undef $x3
- operand 0: killed $cr5lt
LLVM ERROR: Found 1 machine code errors.
```
There are also other existing testcases with same issue. So I add -verify-machineinstrs option to open verifying.
Differential Revision: https://reviews.llvm.org/D55408
llvm-svn: 348566
When doing some instruction scheduling work, we noticed some missing itineraries.
Before we switch to machine scheduler, those missing itineraries might not have impact to actually scheduling,
because we can still get same latency due to default values.
With machine scheduler, however, itineraries will have impact to scheduling.
eg: NumMicroOps will default to be 0 if there is NO itineraries for specific instruction class.
And most of the instruction class with itineraries will have NumMicroOps default to 1.
This will has impact on the count of RetiredMOps, affects the Pending/Available Queue,
then causing different scheduling or suboptimal scheduling further.
This patch is for STWU/STWUX (IIC_LdStStoreUpd ) for P8.
Since there are already multiple IIC for store update, this patch also merge
IIC_LdStSTDU/IIC_LdStStoreUpd to IIC_LdStSTU
IIC_LdStSTDUX to IIC_LdStSTUX
and we add a new testcase in https://reviews.llvm.org/D54699 to show the difference.
Differential Revision: https://reviews.llvm.org/D54700
llvm-svn: 347311
This patch add a STWU testcase for scheduling check.
Currently P7/P8 which use itineraries are missing IIC_LdStStoreUpd,
We use CHECK-ITIN prefix to check P7/P8, then use default for P9 (and future).
We will fix the missing itineraries of IIC_LdStStoreUpd in following patch,
and update this testcase to show the scheduling difference only there.
Differential Revision: https://reviews.llvm.org/D54699
llvm-svn: 347310
Fangrui Song