8309894: compiler/vectorapi/VectorLogicalOpIdentityTest.java fails on SVE system with UseSVE=0

Reviewed-by: phh
Backport-of: 60544f9088c11e4718a9cd77f21792c6ba387440

Author: cost0much

test/hotspot/jtreg/compiler/lib/ir_framework/README.md

@@ -124,8 +124,9 @@ One might also want to restrict the application of certain `@IR` rules depending
 - `applyIfOr`:  Only apply a rule if **at least one** flag has the specified value/range of values.
 
 #### Disable/Enable IR Rules based on available CPU Features
-Sometimes, an `@IR` rule should only be applied if a certain CPU feature is present. This can be done with
-the attributes `applyIfCPUFeatureXXX` in [@IR](./IR.java) which follow the same logic as the `applyIfXXX` methods for flags in the previous section. If a `@Test` annotated method has multiple preconditions (for example `applyIf` and `applyIfCPUFeature`), they are evaluated as a logical conjunction. An example with `applyIfCPUFeatureXXX` can be found in [TestCPUFeatureCheck](../../../testlibrary_tests/ir_framework/tests/TestCPUFeatureCheck.java) (internal framework test).
+Sometimes, an `@IR` rule should only be applied if a certain CPU feature is present. This can be done with the attributes `applyIfCPUFeatureXXX` in [@IR](./IR.java) which follow the same logic as the `applyIfXXX` methods for flags in the previous section. An example with `applyIfCPUFeatureXXX` can be found in [TestCPUFeatureCheck](../../../testlibrary_tests/ir_framework/tests/TestCPUFeatureCheck.java) (internal framework test).
+
+If a `@Test` annotated method has multiple preconditions (for example `applyIf` and `applyIfCPUFeature`), they are evaluated as a logical conjunction. It's worth noting that flags in `applyIf` are checked only if the CPU features in `applyIfCPUFeature` are matched when they are both specified. This avoids the VM flag being evaluated on hardware that does not support it. An example with both `applyIfCPUFeatureXXX` and `applyIfXXX` can be found in [TestPreconditions](../../../testlibrary_tests/ir_framework/tests/TestPreconditions.java) (internal framework test).
 
 #### Implicitly Skipping IR Verification
 An IR verification cannot always be performed. Certain VM flags explicitly disable IR verification, change the IR shape in unexpected ways letting IR rules fail or even make IR verification impossible:

test/hotspot/jtreg/compiler/lib/ir_framework/test/IREncodingPrinter.java

@@ -134,6 +134,15 @@ private boolean shouldApplyIrRule(IR irAnno, String m, int ruleIndex, int ruleMa
         checkIRAnnotations(irAnno);
         if (isIRNodeUnsupported(irAnno)) {
             return false;
+        } else if (irAnno.applyIfCPUFeature().length != 0 && !hasAllRequiredCPUFeature(irAnno.applyIfCPUFeature())) {
+            printDisableReason(m, "Feature constraint not met (applyIfCPUFeature)", irAnno.applyIfCPUFeature(), ruleIndex, ruleMax);
+            return false;
+        } else if (irAnno.applyIfCPUFeatureAnd().length != 0 && !hasAllRequiredCPUFeature(irAnno.applyIfCPUFeatureAnd())) {
+            printDisableReason(m, "Not all feature constraints are met (applyIfCPUFeatureAnd)", irAnno.applyIfCPUFeatureAnd(), ruleIndex, ruleMax);
+            return false;
+        } else if (irAnno.applyIfCPUFeatureOr().length != 0 && !hasAnyRequiredCPUFeature(irAnno.applyIfCPUFeatureOr())) {
+            printDisableReason(m, "None of the feature constraints met (applyIfCPUFeatureOr)", irAnno.applyIfCPUFeatureOr(), ruleIndex, ruleMax);
+            return false;
         } else if (irAnno.applyIf().length != 0 && !hasAllRequiredFlags(irAnno.applyIf(), "applyIf")) {
             printDisableReason(m, "Flag constraint not met (applyIf)", irAnno.applyIf(), ruleIndex, ruleMax);
             return false;
@@ -146,15 +155,6 @@ private boolean shouldApplyIrRule(IR irAnno, String m, int ruleIndex, int ruleMa
         } else if (irAnno.applyIfOr().length != 0 && hasNoRequiredFlags(irAnno.applyIfOr(), "applyIfOr")) {
             printDisableReason(m, "None of the flag constraints met (applyIfOr)", irAnno.applyIfOr(), ruleIndex, ruleMax);
             return false;
-        } else if (irAnno.applyIfCPUFeature().length != 0 && !hasAllRequiredCPUFeature(irAnno.applyIfCPUFeature())) {
-            printDisableReason(m, "Feature constraint not met (applyIfCPUFeature)", irAnno.applyIfCPUFeature(), ruleIndex, ruleMax);
-            return false;
-        } else if (irAnno.applyIfCPUFeatureAnd().length != 0 && !hasAllRequiredCPUFeature(irAnno.applyIfCPUFeatureAnd())) {
-            printDisableReason(m, "Not all feature constraints are met (applyIfCPUFeatureAnd)", irAnno.applyIfCPUFeatureAnd(), ruleIndex, ruleMax);
-            return false;
-        } else if (irAnno.applyIfCPUFeatureOr().length != 0 && !hasAnyRequiredCPUFeature(irAnno.applyIfCPUFeatureOr())) {
-            printDisableReason(m, "None of the feature constraints met (applyIfCPUFeatureOr)", irAnno.applyIfCPUFeatureOr(), ruleIndex, ruleMax);
-            return false;
         } else {
             // All preconditions satisfied: apply rule.
             return true;

test/hotspot/jtreg/compiler/vectorapi/VectorLogicalOpIdentityTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, Arm Limited. All rights reserved.
+ * Copyright (c) 2022, 2023, Arm Limited. All rights reserved.
  * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *

test/hotspot/jtreg/testlibrary_tests/ir_framework/tests/TestPreconditions.java

@@ -56,6 +56,29 @@ public static void testApplyIfCPUFeatureOnly() {}
     @IR(applyIfCPUFeatureAnd = {"asimd", "true", "sse", "true"},
         applyIf = {"LoopMaxUnroll", "= 8"},
         counts = {IRNode.LOOP, ">= 1000"})
-    public static void testApplyBoth() {}
+    public static void testApplyBoth1() {}
 
+    // The IR check should not be applied on aarch64, because the "applyIfAnd"
+    // condition returns false as the VM is run with LoopMaxUnroll=8.
+    // Note that precondition `applyIfCPUFeature` will be evaluated first with
+    // early return. Hence the IR check should not be applied on non-aarch64
+    // systems, and no exception is thrown because we are not checking the value
+    // of the unsupported "UseSVE" flag on non-aarch64 systems.
+    @Test
+    @IR(applyIfCPUFeature = {"asimd", "true"},
+        applyIfAnd = {"UseSVE", "= 0", "LoopMaxUnroll", "= 0"},
+        counts = {IRNode.LOOP, ">= 1000"})
+    public static void testApplyBoth2() {}
+
+    // The IR check should not be applied on x86, because the "applyIfAnd"
+    // condition returns false as the VM is run with LoopMaxUnroll=8.
+    // Note that precondition `applyIfCPUFeature` will be evaluated first with
+    // early return. Hence the IR check should not be applied on non-avx systems,
+    // and no exception is thrown because we are not checking the value of the
+    // unsupported "UseAVX" flag on non-avx systems.
+    @Test
+    @IR(applyIfCPUFeature = {"avx", "true"},
+        applyIfAnd = {"UseAVX", "= 2", "LoopMaxUnroll", "= 0"},
+        counts = {IRNode.LOOP, ">= 1000"})
+    public static void testApplyBoth3() {}
 }