[X86][BtVer2][MCA][NFC] Add CMPEQ one-idioms tests

[lebedev.ri]

Summary

As per Agner's Microarchitecture doc (21.8 AMD Bobcat and Jaguar pipeline - Dependency-breaking instructions), these, like zero-idioms, are dependency-breaking, although they produce ones and still consume resources.

[lebedev.ri]

In D48877#1152141, @andreadb wrote:

In D48877#1152117, @lebedev.ri wrote:

In D48877#1152115, @andreadb wrote:

In D48877#1152098, @RKSimon wrote:

Ok, well, i guess what i was trying to ask/understand is, is that already properly represented https://godbolt.org/g/9rYPYA, or not?

No, we don't properly model dependency breaking instructions yet - zero-idioms are making use of a special case of llvm-mca that assumes dependency breaking if no resources are used - IMO that's something that should be removed and we come up with a better way to model this.

Simon is right on this.
We still don't model dependency breaking instructions. There is already a plan to teach llvm-mca how to identify those instructions, and that is next on my TODO list. Once we have that system in place, we can remove the "zero-latency implies dependency-breaking" hack in llvm-mca.

This patch doesn't do the right thing. The timeline clearly shows how dependencies are not broken.

Ok, that is actually good, i was starting to question my [rudimentary] understanding of all this.

-Andrea

Then, back to square one, are D48876 tests of any use? :)

You can commit those tests to show that we don't correctly model dependency breaking packed compare instructions on BtVer2. However, I would remove the padd from the tests.

@andreadb do you feel like officially LGTM'ing this modulo the nit? :)

[andreadb]

You can commit those tests to show that we don't correctly model dependency breaking packed compare instructions on BtVer2. However, I would remove the padd from the tests.

@andreadb do you feel like officially LGTM'ing this modulo the nit? :)

Yes please. Thanks!

[lebedev.ri]

In D48876#1152421, @andreadb wrote:

You can commit those tests to show that we don't correctly model dependency breaking packed compare instructions on BtVer2. However, I would remove the padd from the tests.

@andreadb do you feel like officially LGTM'ing this modulo the nit? :)

Yes please. Thanks!

Thank you!

llvm/trunk/test/tools/llvm-mca/X86/BtVer2/one-idioms.s

+# NOTE: Assertions have been autogenerated by utils/update_mca_test_checks.py
+# RUN: llvm-mca -mtriple=x86_64-unknown-unknown -mcpu=btver2 -timeline -register-file-stats -iterations=1 < %s | FileCheck %s
+
+# These are dependency-breaking one-idioms.
+# Much like zero-idioms, but they produce ones, and do consume resources.
+
+pcmpeqb   %mm2, %mm2
+pcmpeqd   %mm2, %mm2
+# pcmpeqq %mm2, %mm2 # invalid operand for instruction
+pcmpeqw   %mm2, %mm2
+
+pcmpeqb   %xmm2, %xmm2
+pcmpeqd   %xmm2, %xmm2
+pcmpeqq   %xmm2, %xmm2
+pcmpeqw   %xmm2, %xmm2
+
+vpcmpeqb  %xmm3, %xmm3, %xmm3
+vpcmpeqd  %xmm3, %xmm3, %xmm3
+vpcmpeqq  %xmm3, %xmm3, %xmm3
+vpcmpeqw  %xmm3, %xmm3, %xmm3
+
+vpcmpeqb  %xmm3, %xmm3, %xmm5
+vpcmpeqd  %xmm3, %xmm3, %xmm5
+vpcmpeqq  %xmm3, %xmm3, %xmm5
+vpcmpeqw  %xmm3, %xmm3, %xmm5
+
+# FIXME: their handling is broken in llvm-mca.
+
+# CHECK:      Iterations:        1
+# CHECK-NEXT: Instructions:      15
+# CHECK-NEXT: Total Cycles:      12
+# CHECK-NEXT: Dispatch Width:    2
+# CHECK-NEXT: IPC:               1.25
+# CHECK-NEXT: Block RThroughput: 7.5
+
+# CHECK:      Instruction Info:
+# CHECK-NEXT: [1]: #uOps
+# CHECK-NEXT: [2]: Latency
+# CHECK-NEXT: [3]: RThroughput
+# CHECK-NEXT: [4]: MayLoad
+# CHECK-NEXT: [5]: MayStore
+# CHECK-NEXT: [6]: HasSideEffects
+
+# CHECK:      [1]    [2]    [3]    [4]    [5]    [6]    Instructions:
+# CHECK-NEXT:  1      1     0.50                        pcmpeqb %mm2, %mm2
+# CHECK-NEXT:  1      1     0.50                        pcmpeqd %mm2, %mm2
+# CHECK-NEXT:  1      1     0.50                        pcmpeqw %mm2, %mm2
+# CHECK-NEXT:  1      1     0.50                        pcmpeqb %xmm2, %xmm2
+# CHECK-NEXT:  1      1     0.50                        pcmpeqd %xmm2, %xmm2
+# CHECK-NEXT:  1      1     0.50                        pcmpeqq %xmm2, %xmm2
+# CHECK-NEXT:  1      1     0.50                        pcmpeqw %xmm2, %xmm2
+# CHECK-NEXT:  1      1     0.50                        vpcmpeqb  %xmm3, %xmm3, %xmm3
+# CHECK-NEXT:  1      1     0.50                        vpcmpeqd  %xmm3, %xmm3, %xmm3
+# CHECK-NEXT:  1      1     0.50                        vpcmpeqq  %xmm3, %xmm3, %xmm3
+# CHECK-NEXT:  1      1     0.50                        vpcmpeqw  %xmm3, %xmm3, %xmm3
+# CHECK-NEXT:  1      1     0.50                        vpcmpeqb  %xmm3, %xmm3, %xmm5
+# CHECK-NEXT:  1      1     0.50                        vpcmpeqd  %xmm3, %xmm3, %xmm5
+# CHECK-NEXT:  1      1     0.50                        vpcmpeqq  %xmm3, %xmm3, %xmm5
+# CHECK-NEXT:  1      1     0.50                        vpcmpeqw  %xmm3, %xmm3, %xmm5
+
+# CHECK:      Register File statistics:
+# CHECK-NEXT: Total number of mappings created:    15
+# CHECK-NEXT: Max number of mappings used:         8
+
+# CHECK:      *  Register File #1 -- JFpuPRF:
+# CHECK-NEXT:    Number of physical registers:     72
+# CHECK-NEXT:    Total number of mappings created: 15
+# CHECK-NEXT:    Max number of mappings used:      8
+
+# CHECK:      *  Register File #2 -- JIntegerPRF:
+# CHECK-NEXT:    Number of physical registers:     64
+# CHECK-NEXT:    Total number of mappings created: 0
+# CHECK-NEXT:    Max number of mappings used:      0
+
+# CHECK:      Resources:
+# CHECK-NEXT: [0]   - JALU0
+# CHECK-NEXT: [1]   - JALU1
+# CHECK-NEXT: [2]   - JDiv
+# CHECK-NEXT: [3]   - JFPA
+# CHECK-NEXT: [4]   - JFPM
+# CHECK-NEXT: [5]   - JFPU0
+# CHECK-NEXT: [6]   - JFPU1
+# CHECK-NEXT: [7]   - JLAGU
+# CHECK-NEXT: [8]   - JMul
+# CHECK-NEXT: [9]   - JSAGU
+# CHECK-NEXT: [10]  - JSTC
+# CHECK-NEXT: [11]  - JVALU0
+# CHECK-NEXT: [12]  - JVALU1
+# CHECK-NEXT: [13]  - JVIMUL
+
+# CHECK:      Resource pressure per iteration:
+# CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]    [10]   [11]   [12]   [13]
+# CHECK-NEXT:  -      -      -      -      -     7.00   8.00    -      -      -      -     7.00   8.00    -
+
+# CHECK:      Resource pressure by instruction:
+# CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]    [10]   [11]   [12]   [13]   Instructions:
+# CHECK-NEXT:  -      -      -      -      -      -     1.00    -      -      -      -      -     1.00    -     pcmpeqb %mm2, %mm2
+# CHECK-NEXT:  -      -      -      -      -     1.00    -      -      -      -      -     1.00    -      -     pcmpeqd %mm2, %mm2
+# CHECK-NEXT:  -      -      -      -      -     1.00    -      -      -      -      -     1.00    -      -     pcmpeqw %mm2, %mm2
+# CHECK-NEXT:  -      -      -      -      -      -     1.00    -      -      -      -      -     1.00    -     pcmpeqb %xmm2, %xmm2
+# CHECK-NEXT:  -      -      -      -      -      -     1.00    -      -      -      -      -     1.00    -     pcmpeqd %xmm2, %xmm2
+# CHECK-NEXT:  -      -      -      -      -     1.00    -      -      -      -      -     1.00    -      -     pcmpeqq %xmm2, %xmm2
+# CHECK-NEXT:  -      -      -      -      -     1.00    -      -      -      -      -     1.00    -      -     pcmpeqw %xmm2, %xmm2
+# CHECK-NEXT:  -      -      -      -      -      -     1.00    -      -      -      -      -     1.00    -     vpcmpeqb  %xmm3, %xmm3, %xmm3
+# CHECK-NEXT:  -      -      -      -      -      -     1.00    -      -      -      -      -     1.00    -     vpcmpeqd  %xmm3, %xmm3, %xmm3
+# CHECK-NEXT:  -      -      -      -      -     1.00    -      -      -      -      -     1.00    -      -     vpcmpeqq  %xmm3, %xmm3, %xmm3
+# CHECK-NEXT:  -      -      -      -      -      -     1.00    -      -      -      -      -     1.00    -     vpcmpeqw  %xmm3, %xmm3, %xmm3
+# CHECK-NEXT:  -      -      -      -      -     1.00    -      -      -      -      -     1.00    -      -     vpcmpeqb  %xmm3, %xmm3, %xmm5
+# CHECK-NEXT:  -      -      -      -      -      -     1.00    -      -      -      -      -     1.00    -     vpcmpeqd  %xmm3, %xmm3, %xmm5
+# CHECK-NEXT:  -      -      -      -      -     1.00    -      -      -      -      -     1.00    -      -     vpcmpeqq  %xmm3, %xmm3, %xmm5
+# CHECK-NEXT:  -      -      -      -      -      -     1.00    -      -      -      -      -     1.00    -     vpcmpeqw  %xmm3, %xmm3, %xmm5
+
+# CHECK:      Timeline view:
+# CHECK-NEXT:                     01
+# CHECK-NEXT: Index     0123456789
+
+# CHECK:      [0,0]     DeER .    ..   pcmpeqb  %mm2, %mm2
+# CHECK-NEXT: [0,1]     D=eER.    ..   pcmpeqd  %mm2, %mm2
+# CHECK-NEXT: [0,2]     .D=eER    ..   pcmpeqw  %mm2, %mm2
+# CHECK-NEXT: [0,3]     .DeE-R    ..   pcmpeqb  %xmm2, %xmm2
+# CHECK-NEXT: [0,4]     . DeE-R   ..   pcmpeqd  %xmm2, %xmm2
+# CHECK-NEXT: [0,5]     . D=eER   ..   pcmpeqq  %xmm2, %xmm2
+# CHECK-NEXT: [0,6]     .  D=eER  ..   pcmpeqw  %xmm2, %xmm2
+# CHECK-NEXT: [0,7]     .  DeE-R  ..   vpcmpeqb %xmm3, %xmm3, %xmm3
+# CHECK-NEXT: [0,8]     .   DeE-R ..   vpcmpeqd %xmm3, %xmm3, %xmm3
+# CHECK-NEXT: [0,9]     .   D=eER ..   vpcmpeqq %xmm3, %xmm3, %xmm3
+# CHECK-NEXT: [0,10]    .    D=eER..   vpcmpeqw %xmm3, %xmm3, %xmm3
+# CHECK-NEXT: [0,11]    .    D==eER.   vpcmpeqb %xmm3, %xmm3, %xmm5
+# CHECK-NEXT: [0,12]    .    .D=eER.   vpcmpeqd %xmm3, %xmm3, %xmm5
+# CHECK-NEXT: [0,13]    .    .D==eER   vpcmpeqq %xmm3, %xmm3, %xmm5
+# CHECK-NEXT: [0,14]    .    . D=eER   vpcmpeqw %xmm3, %xmm3, %xmm5
+
+# CHECK:      Average Wait times (based on the timeline view):
+# CHECK-NEXT: [0]: Executions
+# CHECK-NEXT: [1]: Average time spent waiting in a scheduler's queue
+# CHECK-NEXT: [2]: Average time spent waiting in a scheduler's queue while ready
+# CHECK-NEXT: [3]: Average time elapsed from WB until retire stage
+
+# CHECK:            [0]    [1]    [2]    [3]
+# CHECK-NEXT: 0.     1     1.0    1.0    0.0       pcmpeqb  %mm2, %mm2
+# CHECK-NEXT: 1.     1     2.0    0.0    0.0       pcmpeqd  %mm2, %mm2
+# CHECK-NEXT: 2.     1     2.0    0.0    0.0       pcmpeqw  %mm2, %mm2
+# CHECK-NEXT: 3.     1     1.0    1.0    1.0       pcmpeqb  %xmm2, %xmm2
+# CHECK-NEXT: 4.     1     1.0    0.0    1.0       pcmpeqd  %xmm2, %xmm2
+# CHECK-NEXT: 5.     1     2.0    0.0    0.0       pcmpeqq  %xmm2, %xmm2
+# CHECK-NEXT: 6.     1     2.0    0.0    0.0       pcmpeqw  %xmm2, %xmm2
+# CHECK-NEXT: 7.     1     1.0    1.0    1.0       vpcmpeqb %xmm3, %xmm3, %xmm3
+# CHECK-NEXT: 8.     1     1.0    0.0    1.0       vpcmpeqd %xmm3, %xmm3, %xmm3
+# CHECK-NEXT: 9.     1     2.0    0.0    0.0       vpcmpeqq %xmm3, %xmm3, %xmm3
+# CHECK-NEXT: 10.    1     2.0    0.0    0.0       vpcmpeqw %xmm3, %xmm3, %xmm3
+# CHECK-NEXT: 11.    1     3.0    0.0    0.0       vpcmpeqb %xmm3, %xmm3, %xmm5
+# CHECK-NEXT: 12.    1     2.0    0.0    0.0       vpcmpeqd %xmm3, %xmm3, %xmm5
+# CHECK-NEXT: 13.    1     3.0    1.0    0.0       vpcmpeqq %xmm3, %xmm3, %xmm5
+# CHECK-NEXT: 14.    1     2.0    1.0    0.0       vpcmpeqw %xmm3, %xmm3, %xmm5

llvm/trunk/test/tools/llvm-mca/X86/BtVer2/zero-idioms.s

 # NOTE: Assertions have been autogenerated by utils/update_mca_test_checks.py
 # RUN: llvm-mca -mtriple=x86_64-unknown-unknown -mcpu=btver2 -timeline -register-file-stats -iterations=1 < %s | FileCheck %s
 
 subl  %eax, %eax
 subq  %rax, %rax
 xorl  %eax, %eax
 xorq  %rax, %rax
 
 pcmpgtb   %mm2, %mm2
 pcmpgtd   %mm2, %mm2
+# pcmpgtq   %mm2, %mm2 # invalid operand for instruction
 pcmpgtw   %mm2, %mm2
+
 pcmpgtb   %xmm2, %xmm2
 pcmpgtd   %xmm2, %xmm2
 pcmpgtq   %xmm2, %xmm2
 pcmpgtw   %xmm2, %xmm2
+
 vpcmpgtb  %xmm3, %xmm3, %xmm3
 vpcmpgtd  %xmm3, %xmm3, %xmm3
 vpcmpgtq  %xmm3, %xmm3, %xmm3
 vpcmpgtw  %xmm3, %xmm3, %xmm3
 
 vpcmpgtb  %xmm3, %xmm3, %xmm5
 vpcmpgtd  %xmm3, %xmm3, %xmm5
 vpcmpgtq  %xmm3, %xmm3, %xmm5