8350483: AArch64: turn on signum intrinsics by default on Ampere CPUs

cnqpzhang · Andrew Haley · commit f529bf712d89 · 2025-02-26T09:07:07.000Z
Reviewed-by: aph
diff --git a/src/hotspot/cpu/aarch64/vm_version_aarch64.cpp b/src/hotspot/cpu/aarch64/vm_version_aarch64.cpp
@@ -161,6 +161,9 @@ void VM_Version::initialize() {
         (_model == CPU_MODEL_AMPERE_1A || _model == CPU_MODEL_AMPERE_1B)) {
       FLAG_SET_DEFAULT(CodeEntryAlignment, 32);
     }
+    if (FLAG_IS_DEFAULT(UseSignumIntrinsic)) {
+      FLAG_SET_DEFAULT(UseSignumIntrinsic, true);
+    }
   }
 
   // ThunderX

Original file line number	Diff line number	Diff line change
`@@ -161,6 +161,9 @@ void VM_Version::initialize() {`
`161`	`161`	`(_model == CPU_MODEL_AMPERE_1A \|\| _model == CPU_MODEL_AMPERE_1B)) {`
`162`	`162`	`FLAG_SET_DEFAULT(CodeEntryAlignment, 32);`
`163`	`163`	`}`
	`164`	`+ if (FLAG_IS_DEFAULT(UseSignumIntrinsic)) {`
	`165`	`+ FLAG_SET_DEFAULT(UseSignumIntrinsic, true);`
	`166`	`+ }`
`164`	`167`	`}`
`165`	`168`
`166`	`169`	`// ThunderX`