[llvm] 0e20666 - [MCA][LSUnit] Correctly update the internal group flags on store barrier execution. Fixes PR48024.

Andrea Di Biagio via llvm-commits llvm-commits at lists.llvm.org
Sat Oct 31 05:00:44 PDT 2020


Author: Andrea Di Biagio
Date: 2020-10-31T11:57:27Z
New Revision: 0e20666db3ac280affe82d31b6c144923704e9c4

URL: https://github.com/llvm/llvm-project/commit/0e20666db3ac280affe82d31b6c144923704e9c4
DIFF: https://github.com/llvm/llvm-project/commit/0e20666db3ac280affe82d31b6c144923704e9c4.diff

LOG: [MCA][LSUnit] Correctly update the internal group flags on store barrier execution. Fixes PR48024.

This is likely to be a regressigion introduced by my last refactoring of the
LSUnit (commit 5578ec32f9c4f). Before this patch, the
"CurrentStoreBarrierGroupID" index was not correctly reset on store barrier
executions.  This was leading to unexpected crashes like the one reported as
PR48024.

Added: 
    llvm/test/tools/llvm-mca/X86/BtVer2/stmxcsr-ldmxcsr.s
    llvm/test/tools/llvm-mca/X86/Haswell/stmxcsr-ldmxcsr.s

Modified: 
    llvm/lib/MCA/HardwareUnits/LSUnit.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/MCA/HardwareUnits/LSUnit.cpp b/llvm/lib/MCA/HardwareUnits/LSUnit.cpp
index e945e8cecce9..4594368fc0e9 100644
--- a/llvm/lib/MCA/HardwareUnits/LSUnit.cpp
+++ b/llvm/lib/MCA/HardwareUnits/LSUnit.cpp
@@ -243,6 +243,8 @@ void LSUnit::onInstructionExecuted(const InstRef &IR) {
       CurrentStoreGroupID = 0;
     if (GroupID == CurrentLoadBarrierGroupID)
       CurrentLoadBarrierGroupID = 0;
+    if (GroupID == CurrentStoreBarrierGroupID)
+      CurrentStoreBarrierGroupID = 0;
   }
 }
 

diff  --git a/llvm/test/tools/llvm-mca/X86/BtVer2/stmxcsr-ldmxcsr.s b/llvm/test/tools/llvm-mca/X86/BtVer2/stmxcsr-ldmxcsr.s
new file mode 100644
index 000000000000..52bf97732d95
--- /dev/null
+++ b/llvm/test/tools/llvm-mca/X86/BtVer2/stmxcsr-ldmxcsr.s
@@ -0,0 +1,104 @@
+# NOTE: Assertions have been autogenerated by utils/update_mca_test_checks.py
+# RUN: llvm-mca -mtriple=x86_64-unknown-unknown -mcpu=btver2 -timeline -timeline-max-iterations=3 < %s | FileCheck %s
+
+# Code snippet taken from PR48024.
+
+stmxcsr -4(%rsp)
+movl    $-24577, %eax    # imm = 0x9FFF
+andl    -4(%rsp), %eax
+movl    %eax, -8(%rsp)
+ldmxcsr -8(%rsp)
+retq
+
+# CHECK:      Iterations:        100
+# CHECK-NEXT: Instructions:      600
+# CHECK-NEXT: Total Cycles:      704
+# CHECK-NEXT: Total uOps:        600
+
+# CHECK:      Dispatch Width:    2
+# CHECK-NEXT: uOps Per Cycle:    0.85
+# CHECK-NEXT: IPC:               0.85
+# CHECK-NEXT: Block RThroughput: 3.0
+
+# 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 (U)
+
+# CHECK:      [1]    [2]    [3]    [4]    [5]    [6]    Instructions:
+# CHECK-NEXT:  1      1     1.00           *      U     stmxcsr	-4(%rsp)
+# CHECK-NEXT:  1      1     0.50                        movl	$-24577, %eax
+# CHECK-NEXT:  1      4     1.00    *                   andl	-4(%rsp), %eax
+# CHECK-NEXT:  1      1     1.00           *            movl	%eax, -8(%rsp)
+# CHECK-NEXT:  1      3     1.00    *             U     ldmxcsr	-8(%rsp)
+# CHECK-NEXT:  1      4     1.00                  U     retq
+
+# 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: 1.50   1.50    -      -      -      -      -     3.00    -     2.00    -      -      -      -
+
+# 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    -      -      -      -     stmxcsr	-4(%rsp)
+# CHECK-NEXT: 0.50   0.50    -      -      -      -      -      -      -      -      -      -      -      -     movl	$-24577, %eax
+# CHECK-NEXT: 0.50   0.50    -      -      -      -      -     1.00    -      -      -      -      -      -     andl	-4(%rsp), %eax
+# CHECK-NEXT:  -      -      -      -      -      -      -      -      -     1.00    -      -      -      -     movl	%eax, -8(%rsp)
+# CHECK-NEXT:  -      -      -      -      -      -      -     1.00    -      -      -      -      -      -     ldmxcsr	-8(%rsp)
+# CHECK-NEXT: 0.50   0.50    -      -      -      -      -     1.00    -      -      -      -      -      -     retq
+
+# CHECK:      Timeline view:
+# CHECK-NEXT:                     0123456789
+# CHECK-NEXT: Index     0123456789          01234
+
+# CHECK:      [0,0]     DeER .    .    .    .   .   stmxcsr	-4(%rsp)
+# CHECK-NEXT: [0,1]     DeER .    .    .    .   .   movl	$-24577, %eax
+# CHECK-NEXT: [0,2]     .DeeeeER  .    .    .   .   andl	-4(%rsp), %eax
+# CHECK-NEXT: [0,3]     .D====eER .    .    .   .   movl	%eax, -8(%rsp)
+# CHECK-NEXT: [0,4]     . D===eeeER    .    .   .   ldmxcsr	-8(%rsp)
+# CHECK-NEXT: [0,5]     . DeeeeE--R    .    .   .   retq
+# CHECK-NEXT: [1,0]     .  D===eE--R   .    .   .   stmxcsr	-4(%rsp)
+# CHECK-NEXT: [1,1]     .  DeE-----R   .    .   .   movl	$-24577, %eax
+# CHECK-NEXT: [1,2]     .   D====eeeeER.    .   .   andl	-4(%rsp), %eax
+# CHECK-NEXT: [1,3]     .   D========eER    .   .   movl	%eax, -8(%rsp)
+# CHECK-NEXT: [1,4]     .    D=======eeeER  .   .   ldmxcsr	-8(%rsp)
+# CHECK-NEXT: [1,5]     .    D=eeeeE-----R  .   .   retq
+# CHECK-NEXT: [2,0]     .    .D=======eE--R .   .   stmxcsr	-4(%rsp)
+# CHECK-NEXT: [2,1]     .    .DeE---------R .   .   movl	$-24577, %eax
+# CHECK-NEXT: [2,2]     .    . D========eeeeER  .   andl	-4(%rsp), %eax
+# CHECK-NEXT: [2,3]     .    . D============eER .   movl	%eax, -8(%rsp)
+# CHECK-NEXT: [2,4]     .    .  D===========eeeER   ldmxcsr	-8(%rsp)
+# CHECK-NEXT: [2,5]     .    .  D=eeeeE---------R   retq
+
+# 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.     3     4.3    1.0    1.3       stmxcsr	-4(%rsp)
+# CHECK-NEXT: 1.     3     1.0    1.0    4.7       movl	$-24577, %eax
+# CHECK-NEXT: 2.     3     5.0    0.3    0.0       andl	-4(%rsp), %eax
+# CHECK-NEXT: 3.     3     9.0    0.0    0.0       movl	%eax, -8(%rsp)
+# CHECK-NEXT: 4.     3     8.0    0.0    0.0       ldmxcsr	-8(%rsp)
+# CHECK-NEXT: 5.     3     1.7    1.7    5.3       retq
+# CHECK-NEXT:        3     4.8    0.7    1.9       <total>

diff  --git a/llvm/test/tools/llvm-mca/X86/Haswell/stmxcsr-ldmxcsr.s b/llvm/test/tools/llvm-mca/X86/Haswell/stmxcsr-ldmxcsr.s
new file mode 100644
index 000000000000..c976314f0fd2
--- /dev/null
+++ b/llvm/test/tools/llvm-mca/X86/Haswell/stmxcsr-ldmxcsr.s
@@ -0,0 +1,100 @@
+# NOTE: Assertions have been autogenerated by utils/update_mca_test_checks.py
+# RUN: llvm-mca -mtriple=x86_64-unknown-unknown -mcpu=haswell -timeline -timeline-max-iterations=3 < %s | FileCheck %s
+
+# Code snippet taken from PR48024.
+
+stmxcsr -4(%rsp)
+movl    $-24577, %eax    # imm = 0x9FFF
+andl    -4(%rsp), %eax
+movl    %eax, -8(%rsp)
+ldmxcsr -8(%rsp)
+retq
+
+# CHECK:      Iterations:        100
+# CHECK-NEXT: Instructions:      600
+# CHECK-NEXT: Total Cycles:      1304
+# CHECK-NEXT: Total uOps:        1300
+
+# CHECK:      Dispatch Width:    4
+# CHECK-NEXT: uOps Per Cycle:    1.00
+# CHECK-NEXT: IPC:               0.46
+# CHECK-NEXT: Block RThroughput: 3.3
+
+# 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 (U)
+
+# CHECK:      [1]    [2]    [3]    [4]    [5]    [6]    Instructions:
+# CHECK-NEXT:  3      2     1.00           *      U     stmxcsr	-4(%rsp)
+# CHECK-NEXT:  1      1     0.25                        movl	$-24577, %eax
+# CHECK-NEXT:  2      6     0.50    *                   andl	-4(%rsp), %eax
+# CHECK-NEXT:  1      1     1.00           *            movl	%eax, -8(%rsp)
+# CHECK-NEXT:  3      7     1.00    *             U     ldmxcsr	-8(%rsp)
+# CHECK-NEXT:  3      7     1.00                  U     retq
+
+# CHECK:      Resources:
+# CHECK-NEXT: [0]   - HWDivider
+# CHECK-NEXT: [1]   - HWFPDivider
+# CHECK-NEXT: [2]   - HWPort0
+# CHECK-NEXT: [3]   - HWPort1
+# CHECK-NEXT: [4]   - HWPort2
+# CHECK-NEXT: [5]   - HWPort3
+# CHECK-NEXT: [6]   - HWPort4
+# CHECK-NEXT: [7]   - HWPort5
+# CHECK-NEXT: [8]   - HWPort6
+# CHECK-NEXT: [9]   - HWPort7
+
+# CHECK:      Resource pressure per iteration:
+# CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]
+# CHECK-NEXT:  -      -     1.75   1.74   1.67   1.68   2.00   1.75   1.76   1.65
+
+# CHECK:      Resource pressure by instruction:
+# CHECK-NEXT: [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]    Instructions:
+# CHECK-NEXT:  -      -      -      -     0.30    -     1.00   1.00    -     0.70   stmxcsr	-4(%rsp)
+# CHECK-NEXT:  -      -     0.08   0.67    -      -      -     0.04   0.21    -     movl	$-24577, %eax
+# CHECK-NEXT:  -      -     0.42   0.37   0.35   0.65    -     0.01   0.20    -     andl	-4(%rsp), %eax
+# CHECK-NEXT:  -      -      -      -     0.05    -     1.00    -      -     0.95   movl	%eax, -8(%rsp)
+# CHECK-NEXT:  -      -     1.00   0.23   0.34   0.66    -     0.42   0.35    -     ldmxcsr	-8(%rsp)
+# CHECK-NEXT:  -      -     0.25   0.47   0.63   0.37    -     0.28   1.00    -     retq
+
+# CHECK:      Timeline view:
+# CHECK-NEXT:                     0123456789          0123456789
+# CHECK-NEXT: Index     0123456789          0123456789          012
+
+# CHECK:      [0,0]     DeeER.    .    .    .    .    .    .    . .   stmxcsr	-4(%rsp)
+# CHECK-NEXT: [0,1]     DeE-R.    .    .    .    .    .    .    . .   movl	$-24577, %eax
+# CHECK-NEXT: [0,2]     .DeeeeeeER.    .    .    .    .    .    . .   andl	-4(%rsp), %eax
+# CHECK-NEXT: [0,3]     .D======eER    .    .    .    .    .    . .   movl	%eax, -8(%rsp)
+# CHECK-NEXT: [0,4]     . D=====eeeeeeeER   .    .    .    .    . .   ldmxcsr	-8(%rsp)
+# CHECK-NEXT: [0,5]     .  DeeeeeeeE----R   .    .    .    .    . .   retq
+# CHECK-NEXT: [1,0]     .   D====eeE----R   .    .    .    .    . .   stmxcsr	-4(%rsp)
+# CHECK-NEXT: [1,1]     .   DeE---------R   .    .    .    .    . .   movl	$-24577, %eax
+# CHECK-NEXT: [1,2]     .    D=========eeeeeeER  .    .    .    . .   andl	-4(%rsp), %eax
+# CHECK-NEXT: [1,3]     .    D===============eER .    .    .    . .   movl	%eax, -8(%rsp)
+# CHECK-NEXT: [1,4]     .    .D==============eeeeeeeER.    .    . .   ldmxcsr	-8(%rsp)
+# CHECK-NEXT: [1,5]     .    . DeeeeeeeE-------------R.    .    . .   retq
+# CHECK-NEXT: [2,0]     .    .  D=============eeE----R.    .    . .   stmxcsr	-4(%rsp)
+# CHECK-NEXT: [2,1]     .    .  DeE------------------R.    .    . .   movl	$-24577, %eax
+# CHECK-NEXT: [2,2]     .    .   D==================eeeeeeER    . .   andl	-4(%rsp), %eax
+# CHECK-NEXT: [2,3]     .    .   D========================eER   . .   movl	%eax, -8(%rsp)
+# CHECK-NEXT: [2,4]     .    .    D=======================eeeeeeeER   ldmxcsr	-8(%rsp)
+# CHECK-NEXT: [2,5]     .    .    .DeeeeeeeE----------------------R   retq
+
+# 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.     3     6.7    1.0    2.7       stmxcsr	-4(%rsp)
+# CHECK-NEXT: 1.     3     1.0    1.0    9.3       movl	$-24577, %eax
+# CHECK-NEXT: 2.     3     10.0   0.3    0.0       andl	-4(%rsp), %eax
+# CHECK-NEXT: 3.     3     16.0   0.0    0.0       movl	%eax, -8(%rsp)
+# CHECK-NEXT: 4.     3     15.0   0.0    0.0       ldmxcsr	-8(%rsp)
+# CHECK-NEXT: 5.     3     1.0    1.0    13.0      retq
+# CHECK-NEXT:        3     8.3    0.6    4.2       <total>


        


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