RFR 8160885 Unsafe.compareAndExchangeDouble/FloatAcquire should defer to compareAndExchangeLong/IntAcquire

[Paul Sandoz]

Hi,

Please review the simple patch below.

As spotted by Andrew Haley the Unsafe.compareAndExchangeDouble/FloatAcquire 
methods were incorrectly deferring to compareAndExchangeLong/IntVolatile rather 
than compareAndExchangeLong/IntAcquire. Other, related, double/float Unsafe 
methods defer correctly to the long/int variants.

Thanks,
Paul.

diff -r 7ca81adc8bad src/java.base/share/classes/jdk/internal/misc/Unsafe.java
--- a/src/java.base/share/classes/jdk/internal/misc/Unsafe.java Wed Jul 06 
17:38:29 2016 +0200
+++ b/src/java.base/share/classes/jdk/internal/misc/Unsafe.java Wed Jul 06 
19:08:55 2016 +0200
@@ -1709,9 +1709,9 @@
     public final float compareAndExchangeFloatAcquire(Object o, long offset,
                                                   float expected,
                                                   float x) {
-        int w = compareAndExchangeIntVolatile(o, offset,
-                                              
Float.floatToRawIntBits(expected),
-                                              Float.floatToRawIntBits(x));
+        int w = compareAndExchangeIntAcquire(o, offset,
+                                             Float.floatToRawIntBits(expected),
+                                             Float.floatToRawIntBits(x));
         return Float.intBitsToFloat(w);
     }

@@ -1793,9 +1793,9 @@
     public final double compareAndExchangeDoubleAcquire(Object o, long offset,
                                                         double expected,
                                                         double x) {
-        long w = compareAndExchangeLongVolatile(o, offset,
-                                                
Double.doubleToRawLongBits(expected),
-                                                Double.doubleToRawLongBits(x));
+        long w = compareAndExchangeLongAcquire(o, offset,
+                                               
Double.doubleToRawLongBits(expected),
+                                               Double.doubleToRawLongBits(x));
         return Double.longBitsToDouble(w);
     }