RFR: 8305895: Implement JEP 450: Compact Object Headers (Experimental) [v11]

Mon Sep 30 12:40:54 UTC 2024

On Thu, 12 Sep 2024 13:20:14 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

> Indeed, I could re-enable all tests in:
> 
> ```
> test/hotspot/jtreg/compiler/c2/irTests/TestVectorizationMismatchedAccess.java
> test/hotspot/jtreg/compiler/c2/irTests/TestVectorizationNotRun.java
> test/hotspot/jtreg/compiler/loopopts/superword/TestIndependentPacksWithCyclicDependency.java
> ```
> 
> but unfortunately not those others:
> 
> ```
> > > > test/hotspot/jtreg/compiler/loopopts/superword/TestAlignVector.java
> > > > test/hotspot/jtreg/compiler/loopopts/superword/TestMulAddS2I.java
> ```
> 
> I think the issue with all of them is that vectorization in those scenarios only works when the operations inside the loop start at an array index that addresses an element at 8-byte-aligned offset.
> 
> I have filed https://bugs.openjdk.org/browse/JDK-8340010 to track it.

@rkennke A test run of the current changeset in our internal CI system revealed that the following tests fail (because of missing vectorization) when using `-XX:+UnlockExperimentalVMOptions -XX:+UseCompactObjectHeaders -XX:UseSSE=N` with `N <= 3` on an Intel Xeon Platinum 8358 machine:

- test/hotspot/jtreg/compiler/c2/irTests/TestVectorizationNotRun.java
- test/hotspot/jtreg/compiler/c2/irTests/TestVectorizationMismatchedAccess.java
- test/hotspot/jtreg/compiler/vectorization/runner/LoopCombinedOpTest.java

Here are the failure details:

test/hotspot/jtreg/compiler/c2/irTests/TestVectorizationNotRun.java:

1) Method "public static void compiler.c2.irTests.TestVectorizationNotRun.test(byte[],long[])" - [Failed IR rules: 1]:
   * @IR rule 1: "@compiler.lib.ir_framework.IR(phase={DEFAULT}, applyIfPlatformAnd={}, applyIfCPUFeatureOr={}, counts={"_#V#LOAD_VECTOR_L#_", ">=1", "_#STORE_VECTOR#_", ">=1"}, applyIfPlatform={}, applyIfPlatformOr={}, failOn={}, applyIfOr={}, applyIfCPUFeatureAnd={}, applyIf={}, applyIfCPUFeature={}, applyIfAnd={}, applyIfNot={})"
     > Phase "PrintIdeal":
       - counts: Graph contains wrong number of nodes:
         * Constraint 1: "(\\d+(\\s){2}(LoadVector.*)+(\\s){2}===.*vector[A-Za-z]\[2\]:\{long\})"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!
         * Constraint 2: "(\\d+(\\s){2}(StoreVector.*)+(\\s){2}===.*)"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!

test/hotspot/jtreg/compiler/c2/irTests/TestVectorizationMismatchedAccess.java:

1) Method "public static void compiler.c2.irTests.TestVectorizationMismatchedAccess.testByteByte1(byte[],byte[])" - [Failed IR rules: 1]:
   * @IR rule 1: "@compiler.lib.ir_framework.IR(phase={DEFAULT}, applyIfPlatformAnd={}, applyIfCPUFeatureOr={}, counts={"_#V#LOAD_VECTOR_L#_", ">=1", "_#STORE_VECTOR#_", ">=1"}, failOn={}, applyIfPlatform={}, applyIfPlatformOr={}, applyIfOr={}, applyIfCPUFeatureAnd={}, applyIf={}, applyIfCPUFeature={}, applyIfAnd={}, applyIfNot={})"
     > Phase "PrintIdeal":
       - counts: Graph contains wrong number of nodes:
         * Constraint 1: "(\\d+(\\s){2}(LoadVector.*)+(\\s){2}===.*vector[A-Za-z]\[2\]:\{long\})"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!
         * Constraint 2: "(\\d+(\\s){2}(StoreVector.*)+(\\s){2}===.*)"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!

2) Method "public static void compiler.c2.irTests.TestVectorizationMismatchedAccess.testByteByte2(byte[],byte[])" - [Failed IR rules: 1]:
   * @IR rule 1: "@compiler.lib.ir_framework.IR(phase={DEFAULT}, applyIfPlatformAnd={}, applyIfCPUFeatureOr={}, counts={"_#V#LOAD_VECTOR_L#_", ">=1", "_#STORE_VECTOR#_", ">=1"}, failOn={}, applyIfPlatform={}, applyIfPlatformOr={}, applyIfOr={}, applyIfCPUFeatureAnd={}, applyIf={}, applyIfCPUFeature={}, applyIfAnd={}, applyIfNot={})"
     > Phase "PrintIdeal":
       - counts: Graph contains wrong number of nodes:
         * Constraint 1: "(\\d+(\\s){2}(LoadVector.*)+(\\s){2}===.*vector[A-Za-z]\[2\]:\{long\})"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!
         * Constraint 2: "(\\d+(\\s){2}(StoreVector.*)+(\\s){2}===.*)"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!

3) Method "public static void compiler.c2.irTests.TestVectorizationMismatchedAccess.testByteLong1(byte[],long[])" - [Failed IR rules: 1]:
   * @IR rule 1: "@compiler.lib.ir_framework.IR(phase={DEFAULT}, applyIfPlatformAnd={}, applyIfCPUFeatureOr={}, counts={"_#V#LOAD_VECTOR_L#_", ">=1", "_#STORE_VECTOR#_", ">=1"}, failOn={}, applyIfPlatform={}, applyIfPlatformOr={}, applyIfOr={}, applyIfCPUFeatureAnd={}, applyIf={}, applyIfCPUFeature={}, applyIfAnd={}, applyIfNot={})"
     > Phase "PrintIdeal":
       - counts: Graph contains wrong number of nodes:
         * Constraint 1: "(\\d+(\\s){2}(LoadVector.*)+(\\s){2}===.*vector[A-Za-z]\[2\]:\{long\})"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!
         * Constraint 2: "(\\d+(\\s){2}(StoreVector.*)+(\\s){2}===.*)"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!

4) Method "public static void compiler.c2.irTests.TestVectorizationMismatchedAccess.testByteLong2(byte[],long[])" - [Failed IR rules: 1]:
   * @IR rule 1: "@compiler.lib.ir_framework.IR(phase={DEFAULT}, applyIfPlatformAnd={}, applyIfCPUFeatureOr={}, counts={"_#V#LOAD_VECTOR_L#_", ">=1", "_#STORE_VECTOR#_", ">=1"}, failOn={}, applyIfPlatform={}, applyIfPlatformOr={}, applyIfOr={}, applyIfCPUFeatureAnd={}, applyIf={}, applyIfCPUFeature={}, applyIfAnd={}, applyIfNot={})"
     > Phase "PrintIdeal":
       - counts: Graph contains wrong number of nodes:
         * Constraint 1: "(\\d+(\\s){2}(LoadVector.*)+(\\s){2}===.*vector[A-Za-z]\[2\]:\{long\})"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!
         * Constraint 2: "(\\d+(\\s){2}(StoreVector.*)+(\\s){2}===.*)"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!

5) Method "public static void compiler.c2.irTests.TestVectorizationMismatchedAccess.testByteLong3(byte[],long[])" - [Failed IR rules: 1]:
   * @IR rule 1: "@compiler.lib.ir_framework.IR(phase={DEFAULT}, applyIfPlatformAnd={}, applyIfCPUFeatureOr={}, counts={"_#V#LOAD_VECTOR_L#_", ">=1", "_#STORE_VECTOR#_", ">=1"}, failOn={}, applyIfPlatform={}, applyIfPlatformOr={}, applyIfOr={}, applyIfCPUFeatureAnd={}, applyIf={}, applyIfCPUFeature={}, applyIfAnd={}, applyIfNot={})"
     > Phase "PrintIdeal":
       - counts: Graph contains wrong number of nodes:
         * Constraint 1: "(\\d+(\\s){2}(LoadVector.*)+(\\s){2}===.*vector[A-Za-z]\[2\]:\{long\})"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!
         * Constraint 2: "(\\d+(\\s){2}(StoreVector.*)+(\\s){2}===.*)"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!

6) Method "public static void compiler.c2.irTests.TestVectorizationMismatchedAccess.testByteLong5(byte[],long[],int,int)" - [Failed IR rules: 1]:
   * @IR rule 1: "@compiler.lib.ir_framework.IR(phase={DEFAULT}, applyIfPlatformAnd={}, applyIfCPUFeatureOr={}, counts={"_#V#LOAD_VECTOR_L#_", ">=1", "_#STORE_VECTOR#_", ">=1"}, failOn={}, applyIfPlatform={}, applyIfPlatformOr={}, applyIfOr={}, applyIfCPUFeatureAnd={}, applyIf={}, applyIfCPUFeature={}, applyIfAnd={}, applyIfNot={})"
     > Phase "PrintIdeal":
       - counts: Graph contains wrong number of nodes:
         * Constraint 1: "(\\d+(\\s){2}(LoadVector.*)+(\\s){2}===.*vector[A-Za-z]\[2\]:\{long\})"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!
         * Constraint 2: "(\\d+(\\s){2}(StoreVector.*)+(\\s){2}===.*)"
           - Failed comparison: [found] 0 >= 1 [given]
           - No nodes matched!

test/hotspot/jtreg/compiler/vectorization/runner/LoopCombinedOpTest.java:

1) Method "public int[] compiler.vectorization.runner.LoopCombinedOpTest.multipleOpsWith2DifferentTypesAndComplexExpression()" - [Failed IR rules: 1]:
   * @IR rule 1: "@compiler.lib.ir_framework.IR(phase={DEFAULT}, applyIfPlatformAnd={}, applyIfCPUFeatureOr={"asimd", "true", "sse2", "true"}, counts={"_#STORE_VECTOR#_", ">0"}, failOn={}, applyIfPlatform={}, applyIfPlatformOr={}, applyIfOr={}, applyIfCPUFeatureAnd={}, applyIf={}, applyIfCPUFeature={}, applyIfAnd={}, applyIfNot={})"
     > Phase "PrintIdeal":
       - counts: Graph contains wrong number of nodes:
         * Constraint 1: "(\\d+(\\s){2}(StoreVector.*)+(\\s){2}===.*)"
           - Failed comparison: [found] 0 > 0 [given]
           - No nodes matched!

2) Method "public int[] compiler.vectorization.runner.LoopCombinedOpTest.multipleOpsWith2DifferentTypesAndInvariant()" - [Failed IR rules: 1]:
   * @IR rule 1: "@compiler.lib.ir_framework.IR(phase={DEFAULT}, applyIfPlatformAnd={}, applyIfCPUFeatureOr={"asimd", "true", "sse2", "true"}, counts={"_#STORE_VECTOR#_", ">0"}, failOn={}, applyIfPlatform={}, applyIfPlatformOr={}, applyIfOr={}, applyIfCPUFeatureAnd={}, applyIf={}, applyIfCPUFeature={}, applyIfAnd={}, applyIfNot={})"
     > Phase "PrintIdeal":
       - counts: Graph contains wrong number of nodes:
         * Constraint 1: "(\\d+(\\s){2}(StoreVector.*)+(\\s){2}===.*)"
           - Failed comparison: [found] 0 > 0 [given]
           - No nodes matched!

-------------

PR Comment: https://git.openjdk.org/jdk/pull/20677#issuecomment-2383072505