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Delegate to Java's implementation of signum for Long and Int. #23

Merged
merged 1 commit into from

2 participants

@ijuma

The Java implementation is faster as it doesn't have branches.

java.lang.Math includes implementations of signum for Double and Float,
but I didn't change the ones in scala.math because there is a difference
on how negative zero is handled.

@ijuma ijuma Delegate to Java's implementation of signum for Long and Int.
The Java implementation is faster as it doesn't have branches.

java.lang.Math includes implementations of signum for Double and Float,
but I didn't change the ones in scala.math because there is a difference
on how negative zero is handled.
771f5ca
@paulp paulp merged commit 771f5ca into scala:master
@ijuma

Thanks!

@paulp paulp referenced this pull request from a commit
@paulp paulp SI-6546 InnerClasses attribute refers to absent class
At issue is that the optimizer would eliminate closure classes
completely, then neglect to eliminate those classes from the
container's InnerClasses attribute. This breaks tooling which
expects those entries to correspond to real classes.

The code changes are by mgarcia - I only added the test case,
which verifies that after being compiled under -optimise, there
are no inner classes. Before/after:

  7,8d6
  <   InnerClasses:
  <        public final #22; //class A_1$$anonfun$f$1
  37,45c35,40
  <   #21 = Utf8               A_1$$anonfun$f$1
  <   #22 = Class              #21            //  A_1$$anonfun$f$1
  <   #23 = Utf8               Code
  ---
  >   #21 = Utf8               Code
2c6e57f
@paulp paulp referenced this pull request from a commit
@paulp paulp SI-6546 InnerClasses attribute refers to absent class
At issue is that the optimizer would eliminate closure classes
completely, then neglect to eliminate those classes from the
container's InnerClasses attribute. This breaks tooling which
expects those entries to correspond to real classes.

The code change is essentially mgarcia's - I minimized it and
put the caches in perRunCaches, and added the test case which
verifies that after being compiled under -optimise, there are
no inner classes. Before/after:

  7,8d6
  <   InnerClasses:
  <        public final #22; //class A_1$$anonfun$f$1
  37,45c35,40
  <   #21 = Utf8               A_1$$anonfun$f$1
  <   #22 = Class              #21            //  A_1$$anonfun$f$1
  <   #23 = Utf8               Code
  ---
  >   #21 = Utf8               Code
075f6f2
@retronym retronym referenced this pull request from a commit in retronym/scala
@retronym retronym SI-7965 Support calls to MethodHandle.{invoke,invokeExact}
These methods are "signature polymorphic", which means that compiler
should not:
  a) adapt the arguments to `Object`
  b) wrap the repeated parameters in an array
  c) adapt the result type to `Object` if the enclosing expression
     is a cast or if the application appears in the statement position
     of a block.

Dispiritingly, my initial attempt to implement this touched the type
checker, uncurry, erasure, and the backend.

However, I realized we could centralize handling of this in the typer
if at each application we substituted the signature polymorphic
symbol with a clone that carried its implied signature, which is
derived from the types of the arguments (typechecked without an
expected type) and position within and enclosing cast or block.

The test case requires Java 7+ to compile so is currently embedded
in a conditionally compiled block of code in a run test.

We ought to create a partest category for modern JVMs so we can
write such tests in a more natural style.

Here's how this looks in bytecode. Note the `bipush` / `istore`
before/after the invocation of `invokeExact`, and the descriptor
`(LO$;I)I`.

```
% cat sandbox/poly-sig.scala && qscala Test && echo ':javap Test$#main' | qscala
import java.lang.invoke._

object O {
  def bar(x: Int): Int = -x
}

object Test {
  def main(args: Array[String]): Unit = {
    def lookup(name: String, params: Array[Class[_]], ret: Class[_]) = {
      val lookup = java.lang.invoke.MethodHandles.lookup
      val mt = MethodType.methodType(ret, params)
      lookup.findVirtual(O.getClass, name, mt)
    }
    def lookupBar = lookup("bar", Array(classOf[Int]), classOf[Int])

    val barResult = lookupBar.invokeExact(O, 42).asInstanceOf[Int]
    ()
  }
}

scala> :javap Test$#main
  public void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=2
         0: aload_0
         1: invokespecial #18                 // Method lookupBar$1:()Ljava/lang/invoke/MethodHandle;
         4: getstatic     #23                 // Field O$.MODULE$:LO$;
         7: bipush        42
         9: invokevirtual #29                 // Method java/lang/invoke/MethodHandle.invokeExact:(LO$;I)I
        12: istore_2
        13: return
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0      14     0  this   LTest$;
            0      14     1  args   [Ljava/lang/String;
           13       0     2 barResult   I
      LineNumberTable:
        line 16: 0
}
```

I've run this test across our active JVMs:

```
% for v in 1.6 1.7 1.8; do java_use $v; pt --terse test/files/run/t7965.scala || break; done
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-466.1-11M4716)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-466.1, mixed mode)
Selected 1 tests drawn from specified tests

# starting 1 test in run
.

1/1 passed (elapsed time: 00:00:02)
Test Run PASSED
java version "1.7.0_71"
Java(TM) SE Runtime Environment (build 1.7.0_71-b14)
Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)
Selected 1 tests drawn from specified tests

# starting 1 test in run
.

1/1 passed (elapsed time: 00:00:07)
Test Run PASSED
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)
Selected 1 tests drawn from specified tests

# starting 1 test in run
.

1/1 passed (elapsed time: 00:00:05)
Test Run PASSED
```

# Please enter the commit message for your changes. Lines starting
# with '#' will be ignored, and an empty message aborts the commit.
#
# Date:      Thu Nov 20 23:26:16 2014 +1000
#
# On branch ticket/7965
# Your branch is up-to-date with 'retronym/ticket/7965'.
#
# Changes to be committed:
#	modified:   src/compiler/scala/tools/nsc/typechecker/Typers.scala
#	modified:   src/reflect/scala/reflect/internal/Definitions.scala
#	modified:   src/reflect/scala/reflect/internal/StdNames.scala
#	new file:   test/files/run/t7965.scala
#
# Untracked files:
#	pack/
#
c6910a8
@retronym retronym referenced this pull request from a commit in retronym/scala
@retronym retronym SI-7965 Support calls to MethodHandle.{invoke,invokeExact}
These methods are "signature polymorphic", which means that compiler
should not:
  a. adapt the arguments to `Object`
  b. wrap the repeated parameters in an array
  c. adapt the result type to `Object` if the enclosing expression
     is a cast or if the application appears in the statement position
     of a block.

Dispiritingly, my initial attempt to implement this touched the type
checker, uncurry, erasure, and the backend.

However, I realized we could centralize handling of this in the typer
if at each application we substituted the signature polymorphic
symbol with a clone that carried its implied signature, which is
derived from the types of the arguments (typechecked without an
expected type) and position within and enclosing cast or block.

The test case requires Java 7+ to compile so is currently embedded
in a conditionally compiled block of code in a run test.

We ought to create a partest category for modern JVMs so we can
write such tests in a more natural style.

Here's how this looks in bytecode. Note the `bipush` / `istore`
before/after the invocation of `invokeExact`, and the descriptor
`(LO$;I)I`.

```
% cat sandbox/poly-sig.scala && qscala Test && echo ':javap Test$#main' | qscala
import java.lang.invoke._

object O {
  def bar(x: Int): Int = -x
}

object Test {
  def main(args: Array[String]): Unit = {
    def lookup(name: String, params: Array[Class[_]], ret: Class[_]) = {
      val lookup = java.lang.invoke.MethodHandles.lookup
      val mt = MethodType.methodType(ret, params)
      lookup.findVirtual(O.getClass, name, mt)
    }
    def lookupBar = lookup("bar", Array(classOf[Int]), classOf[Int])

    val barResult = lookupBar.invokeExact(O, 42).asInstanceOf[Int]
    ()
  }
}

scala> :javap Test$#main
  public void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=2
         0: aload_0
         1: invokespecial #18                 // Method lookupBar$1:()Ljava/lang/invoke/MethodHandle;
         4: getstatic     #23                 // Field O$.MODULE$:LO$;
         7: bipush        42
         9: invokevirtual #29                 // Method java/lang/invoke/MethodHandle.invokeExact:(LO$;I)I
        12: istore_2
        13: return
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0      14     0  this   LTest$;
            0      14     1  args   [Ljava/lang/String;
           13       0     2 barResult   I
      LineNumberTable:
        line 16: 0
}
```

I've run this test across our active JVMs:

```
% for v in 1.6 1.7 1.8; do java_use $v; pt --terse test/files/run/t7965.scala || break; done
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-466.1-11M4716)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-466.1, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:02)
Test Run PASSED
java version "1.7.0_71"
Java(TM) SE Runtime Environment (build 1.7.0_71-b14)
Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:07)
Test Run PASSED
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:05)
Test Run PASSED
```
28e725e
@retronym retronym referenced this pull request from a commit in retronym/scala
@retronym retronym SI-7965 Support calls to MethodHandle.{invoke,invokeExact}
These methods are "signature polymorphic", which means that compiler
should not:
  1. adapt the arguments to `Object`
  2. wrap the repeated parameters in an array
  3. adapt the result type to `Object` if the enclosing expression
     is a cast or if the application appears in the statement position
     of a block.

Dispiritingly, my initial attempt to implement this touched the type
checker, uncurry, erasure, and the backend.

However, I realized we could centralize handling of this in the typer
if at each application we substituted the signature polymorphic
symbol with a clone that carried its implied signature, which is
derived from the types of the arguments (typechecked without an
expected type) and position within and enclosing cast or block.

The test case requires Java 7+ to compile so is currently embedded
in a conditionally compiled block of code in a run test.

We ought to create a partest category for modern JVMs so we can
write such tests in a more natural style.

Here's how this looks in bytecode. Note the `bipush` / `istore`
before/after the invocation of `invokeExact`, and the descriptor
`(LO$;I)I`.

```
% cat sandbox/poly-sig.scala && qscala Test && echo ':javap Test$#main' | qscala
import java.lang.invoke._

object O {
  def bar(x: Int): Int = -x
}

object Test {
  def main(args: Array[String]): Unit = {
    def lookup(name: String, params: Array[Class[_]], ret: Class[_]) = {
      val lookup = java.lang.invoke.MethodHandles.lookup
      val mt = MethodType.methodType(ret, params)
      lookup.findVirtual(O.getClass, name, mt)
    }
    def lookupBar = lookup("bar", Array(classOf[Int]), classOf[Int])

    val barResult = lookupBar.invokeExact(O, 42).asInstanceOf[Int]
    ()
  }
}

scala> :javap Test$#main
  public void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=2
         0: aload_0
         1: invokespecial #18                 // Method lookupBar$1:()Ljava/lang/invoke/MethodHandle;
         4: getstatic     #23                 // Field O$.MODULE$:LO$;
         7: bipush        42
         9: invokevirtual #29                 // Method java/lang/invoke/MethodHandle.invokeExact:(LO$;I)I
        12: istore_2
        13: return
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0      14     0  this   LTest$;
            0      14     1  args   [Ljava/lang/String;
           13       0     2 barResult   I
      LineNumberTable:
        line 16: 0
}
```

I've run this test across our active JVMs:

```
% for v in 1.6 1.7 1.8; do java_use $v; pt --terse test/files/run/t7965.scala || break; done
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-466.1-11M4716)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-466.1, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:02)
Test Run PASSED
java version "1.7.0_71"
Java(TM) SE Runtime Environment (build 1.7.0_71-b14)
Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:07)
Test Run PASSED
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:05)
Test Run PASSED
```

# Please enter the commit message for your changes. Lines starting
# with '#' will be kept; you may remove them yourself if you want to.
# An empty message aborts the commit.
#
# Date:      Thu Nov 20 23:26:16 2014 +1000
#
# On branch ticket/7965
# Your branch is up-to-date with 'retronym/ticket/7965'.
#
# Changes to be committed:
#	modified:   src/compiler/scala/tools/nsc/typechecker/Typers.scala
#	modified:   src/reflect/scala/reflect/internal/Definitions.scala
#	modified:   src/reflect/scala/reflect/internal/StdNames.scala
#	new file:   test/files/run/t7965.scala
#
# Untracked files:
#	pack/
#
5f3f857
@retronym retronym referenced this pull request from a commit in retronym/scala
@retronym retronym SI-7965 Support calls to MethodHandle.{invoke,invokeExact}
These methods are "signature polymorphic", which means that compiler
should not:
  1. adapt the arguments to `Object`
  2. wrap the repeated parameters in an array
  3. adapt the result type to `Object` if the enclosing expression
     is a cast or if the application appears in the statement position
     of a block.

Dispiritingly, my initial attempt to implement this touched the type
checker, uncurry, erasure, and the backend.

However, I realized we could centralize handling of this in the typer
if at each application we substituted the signature polymorphic
symbol with a clone that carried its implied signature, which is
derived from the types of the arguments (typechecked without an
expected type) and position within and enclosing cast or block.

The test case requires Java 7+ to compile so is currently embedded
in a conditionally compiled block of code in a run test.

We ought to create a partest category for modern JVMs so we can
write such tests in a more natural style.

Here's how this looks in bytecode. Note the `bipush` / `istore`
before/after the invocation of `invokeExact`, and the descriptor
`(LO$;I)I`.

```
% cat sandbox/poly-sig.scala && qscala Test && echo ':javap Test$#main' | qscala
import java.lang.invoke._

object O {
  def bar(x: Int): Int = -x
}

object Test {
  def main(args: Array[String]): Unit = {
    def lookup(name: String, params: Array[Class[_]], ret: Class[_]) = {
      val lookup = java.lang.invoke.MethodHandles.lookup
      val mt = MethodType.methodType(ret, params)
      lookup.findVirtual(O.getClass, name, mt)
    }
    def lookupBar = lookup("bar", Array(classOf[Int]), classOf[Int])

    val barResult = lookupBar.invokeExact(O, 42).asInstanceOf[Int]
    ()
  }
}

scala> :javap Test$#main
  public void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=2
         0: aload_0
         1: invokespecial #18                 // Method lookupBar$1:()Ljava/lang/invoke/MethodHandle;
         4: getstatic     #23                 // Field O$.MODULE$:LO$;
         7: bipush        42
         9: invokevirtual #29                 // Method java/lang/invoke/MethodHandle.invokeExact:(LO$;I)I
        12: istore_2
        13: return
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0      14     0  this   LTest$;
            0      14     1  args   [Ljava/lang/String;
           13       0     2 barResult   I
      LineNumberTable:
        line 16: 0
}
```

I've run this test across our active JVMs:

```
% for v in 1.6 1.7 1.8; do java_use $v; pt --terse test/files/run/t7965.scala || break; done
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-466.1-11M4716)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-466.1, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:02)
Test Run PASSED
java version "1.7.0_71"
Java(TM) SE Runtime Environment (build 1.7.0_71-b14)
Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:07)
Test Run PASSED
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:05)
Test Run PASSED
```

# Please enter the commit message for your changes. Lines starting
# with '#' will be kept; you may remove them yourself if you want to.
# An empty message aborts the commit.
#
# Date:      Thu Nov 20 23:26:16 2014 +1000
#
# On branch ticket/7965
# Your branch is up-to-date with 'retronym/ticket/7965'.
#
# Changes to be committed:
#	modified:   src/compiler/scala/tools/nsc/typechecker/Typers.scala
#	modified:   src/reflect/scala/reflect/internal/Definitions.scala
#	modified:   src/reflect/scala/reflect/internal/StdNames.scala
#	new file:   test/files/run/t7965.scala
#
# Untracked files:
#	pack/
#
e599c80
@retronym retronym referenced this pull request from a commit in retronym/scala
@retronym retronym SI-7965 Support calls to MethodHandle.{invoke,invokeExact}
These methods are "signature polymorphic", which means that compiler
should not:
  1. adapt the arguments to `Object`
  2. wrap the repeated parameters in an array
  3. adapt the result type to `Object` if the enclosing expression
     is a cast or if the application appears in the statement position
     of a block.

Dispiritingly, my initial attempt to implement this touched the type
checker, uncurry, erasure, and the backend.

However, I realized we could centralize handling of this in the typer
if at each application we substituted the signature polymorphic
symbol with a clone that carried its implied signature, which is
derived from the types of the arguments (typechecked without an
expected type) and position within and enclosing cast or block.

The test case requires Java 7+ to compile so is currently embedded
in a conditionally compiled block of code in a run test.

We ought to create a partest category for modern JVMs so we can
write such tests in a more natural style.

Here's how this looks in bytecode. Note the `bipush` / `istore`
before/after the invocation of `invokeExact`, and the descriptor
`(LO$;I)I`.

```
% cat sandbox/poly-sig.scala && qscala Test && echo ':javap Test$#main' | qscala
import java.lang.invoke._

object O {
  def bar(x: Int): Int = -x
}

object Test {
  def main(args: Array[String]): Unit = {
    def lookup(name: String, params: Array[Class[_]], ret: Class[_]) = {
      val lookup = java.lang.invoke.MethodHandles.lookup
      val mt = MethodType.methodType(ret, params)
      lookup.findVirtual(O.getClass, name, mt)
    }
    def lookupBar = lookup("bar", Array(classOf[Int]), classOf[Int])

    val barResult = lookupBar.invokeExact(O, 42).asInstanceOf[Int]
    ()
  }
}

scala> :javap Test$#main
  public void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=2
         0: aload_0
         1: invokespecial #18                 // Method lookupBar$1:()Ljava/lang/invoke/MethodHandle;
         4: getstatic     #23                 // Field O$.MODULE$:LO$;
         7: bipush        42
         9: invokevirtual #29                 // Method java/lang/invoke/MethodHandle.invokeExact:(LO$;I)I
        12: istore_2
        13: return
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0      14     0  this   LTest$;
            0      14     1  args   [Ljava/lang/String;
           13       0     2 barResult   I
      LineNumberTable:
        line 16: 0
}
```

I've run this test across our active JVMs:

```
% for v in 1.6 1.7 1.8; do java_use $v; pt --terse test/files/run/t7965.scala || break; done
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-466.1-11M4716)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-466.1, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:02)
Test Run PASSED
java version "1.7.0_71"
Java(TM) SE Runtime Environment (build 1.7.0_71-b14)
Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:07)
Test Run PASSED
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:05)
Test Run PASSED
```

# Please enter the commit message for your changes. Lines starting
# with '#' will be kept; you may remove them yourself if you want to.
# An empty message aborts the commit.
#
# Date:      Thu Nov 20 23:26:16 2014 +1000
#
# On branch ticket/7965
# Your branch is up-to-date with 'retronym/ticket/7965'.
#
# Changes to be committed:
#	modified:   src/compiler/scala/tools/nsc/typechecker/Typers.scala
#	modified:   src/reflect/scala/reflect/internal/Definitions.scala
#	modified:   src/reflect/scala/reflect/internal/StdNames.scala
#	new file:   test/files/run/t7965.scala
#
# Untracked files:
#	pack/
#
902db4e
@retronym retronym referenced this pull request from a commit in retronym/scala
@retronym retronym SI-7965 Support calls to MethodHandle.{invoke,invokeExact}
These methods are "signature polymorphic", which means that compiler
should not:
  1. adapt the arguments to `Object`
  2. wrap the repeated parameters in an array
  3. adapt the result type to `Object` if the enclosing expression
     is a cast or if the application appears in the statement position
     of a block.

Dispiritingly, my initial attempt to implement this touched the type
checker, uncurry, erasure, and the backend.

However, I realized we could centralize handling of this in the typer
if at each application we substituted the signature polymorphic
symbol with a clone that carried its implied signature, which is
derived from the types of the arguments (typechecked without an
expected type) and position within and enclosing cast or block.

The test case requires Java 7+ to compile so is currently embedded
in a conditionally compiled block of code in a run test.

We ought to create a partest category for modern JVMs so we can
write such tests in a more natural style.

Here's how this looks in bytecode. Note the `bipush` / `istore`
before/after the invocation of `invokeExact`, and the descriptor
`(LO$;I)I`.

```
% cat sandbox/poly-sig.scala && qscala Test && echo ':javap Test$#main' | qscala
import java.lang.invoke._

object O {
  def bar(x: Int): Int = -x
}

object Test {
  def main(args: Array[String]): Unit = {
    def lookup(name: String, params: Array[Class[_]], ret: Class[_]) = {
      val lookup = java.lang.invoke.MethodHandles.lookup
      val mt = MethodType.methodType(ret, params)
      lookup.findVirtual(O.getClass, name, mt)
    }
    def lookupBar = lookup("bar", Array(classOf[Int]), classOf[Int])

    val barResult = lookupBar.invokeExact(O, 42).asInstanceOf[Int]
    ()
  }
}

scala> :javap Test$#main
  public void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=2
         0: aload_0
         1: invokespecial #18                 // Method lookupBar$1:()Ljava/lang/invoke/MethodHandle;
         4: getstatic     #23                 // Field O$.MODULE$:LO$;
         7: bipush        42
         9: invokevirtual #29                 // Method java/lang/invoke/MethodHandle.invokeExact:(LO$;I)I
        12: istore_2
        13: return
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0      14     0  this   LTest$;
            0      14     1  args   [Ljava/lang/String;
           13       0     2 barResult   I
      LineNumberTable:
        line 16: 0
}
```

I've run this test across our active JVMs:

```
% for v in 1.6 1.7 1.8; do java_use $v; pt --terse test/files/run/t7965.scala || break; done
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-466.1-11M4716)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-466.1, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:02)
Test Run PASSED
java version "1.7.0_71"
Java(TM) SE Runtime Environment (build 1.7.0_71-b14)
Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:07)
Test Run PASSED
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:05)
Test Run PASSED
```

# Please enter the commit message for your changes. Lines starting
# with '#' will be kept; you may remove them yourself if you want to.
# An empty message aborts the commit.
#
# Date:      Thu Nov 20 23:26:16 2014 +1000
#
# On branch ticket/7965
# Your branch is up-to-date with 'retronym/ticket/7965'.
#
# Changes to be committed:
#	modified:   src/compiler/scala/tools/nsc/typechecker/Typers.scala
#	modified:   src/reflect/scala/reflect/internal/Definitions.scala
#	modified:   src/reflect/scala/reflect/internal/StdNames.scala
#	new file:   test/files/run/t7965.scala
#
# Untracked files:
#	pack/
#
9cf83ed
@retronym retronym referenced this pull request from a commit in retronym/scala
@retronym retronym SI-7965 Support calls to MethodHandle.{invoke,invokeExact}
These methods are "signature polymorphic", which means that compiler
should not:
  1. adapt the arguments to `Object`
  2. wrap the repeated parameters in an array
  3. adapt the result type to `Object` if the enclosing expression
     is a cast or if the application appears in the statement position
     of a block.

Dispiritingly, my initial attempt to implement this touched the type
checker, uncurry, erasure, and the backend.

However, I realized we could centralize handling of this in the typer
if at each application we substituted the signature polymorphic
symbol with a clone that carried its implied signature, which is
derived from the types of the arguments (typechecked without an
expected type) and position within and enclosing cast or block.

The test case requires Java 7+ to compile so is currently embedded
in a conditionally compiled block of code in a run test.

We ought to create a partest category for modern JVMs so we can
write such tests in a more natural style.

Here's how this looks in bytecode. Note the `bipush` / `istore`
before/after the invocation of `invokeExact`, and the descriptor
`(LO$;I)I`.

```
% cat sandbox/poly-sig.scala && qscala Test && echo ':javap Test$#main' | qscala
import java.lang.invoke._

object O {
  def bar(x: Int): Int = -x
}

object Test {
  def main(args: Array[String]): Unit = {
    def lookup(name: String, params: Array[Class[_]], ret: Class[_]) = {
      val lookup = java.lang.invoke.MethodHandles.lookup
      val mt = MethodType.methodType(ret, params)
      lookup.findVirtual(O.getClass, name, mt)
    }
    def lookupBar = lookup("bar", Array(classOf[Int]), classOf[Int])

    val barResult = lookupBar.invokeExact(O, 42).asInstanceOf[Int]
    ()
  }
}

scala> :javap Test$#main
  public void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=2
         0: aload_0
         1: invokespecial #18                 // Method lookupBar$1:()Ljava/lang/invoke/MethodHandle;
         4: getstatic     #23                 // Field O$.MODULE$:LO$;
         7: bipush        42
         9: invokevirtual #29                 // Method java/lang/invoke/MethodHandle.invokeExact:(LO$;I)I
        12: istore_2
        13: return
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0      14     0  this   LTest$;
            0      14     1  args   [Ljava/lang/String;
           13       0     2 barResult   I
      LineNumberTable:
        line 16: 0
}
```

I've run this test across our active JVMs:

```
% for v in 1.6 1.7 1.8; do java_use $v; pt --terse test/files/run/t7965.scala || break; done
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-466.1-11M4716)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-466.1, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:02)
Test Run PASSED
java version "1.7.0_71"
Java(TM) SE Runtime Environment (build 1.7.0_71-b14)
Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:07)
Test Run PASSED
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:05)
Test Run PASSED
```
612db05
@retronym retronym referenced this pull request from a commit in retronym/scala
@retronym retronym SI-7965 Support calls to MethodHandle.{invoke,invokeExact}
These methods are "signature polymorphic", which means that compiler
should not:
  1. adapt the arguments to `Object`
  2. wrap the repeated parameters in an array
  3. adapt the result type to `Object` if the enclosing expression
     is a cast or if the application appears in the statement position
     of a block.

Dispiritingly, my initial attempt to implement this touched the type
checker, uncurry, erasure, and the backend.

However, I realized we could centralize handling of this in the typer
if at each application we substituted the signature polymorphic
symbol with a clone that carried its implied signature, which is
derived from the types of the arguments (typechecked without an
expected type) and position within and enclosing cast or block.

The test case requires Java 7+ to compile so is currently embedded
in a conditionally compiled block of code in a run test.

We ought to create a partest category for modern JVMs so we can
write such tests in a more natural style.

Here's how this looks in bytecode. Note the `bipush` / `istore`
before/after the invocation of `invokeExact`, and the descriptor
`(LO$;I)I`.

```
% cat sandbox/poly-sig.scala && qscala Test && echo ':javap Test$#main' | qscala
import java.lang.invoke._

object O {
  def bar(x: Int): Int = -x
}

object Test {
  def main(args: Array[String]): Unit = {
    def lookup(name: String, params: Array[Class[_]], ret: Class[_]) = {
      val lookup = java.lang.invoke.MethodHandles.lookup
      val mt = MethodType.methodType(ret, params)
      lookup.findVirtual(O.getClass, name, mt)
    }
    def lookupBar = lookup("bar", Array(classOf[Int]), classOf[Int])

    val barResult = lookupBar.invokeExact(O, 42).asInstanceOf[Int]
    ()
  }
}

scala> :javap Test$#main
  public void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=2
         0: aload_0
         1: invokespecial #18                 // Method lookupBar$1:()Ljava/lang/invoke/MethodHandle;
         4: getstatic     #23                 // Field O$.MODULE$:LO$;
         7: bipush        42
         9: invokevirtual #29                 // Method java/lang/invoke/MethodHandle.invokeExact:(LO$;I)I
        12: istore_2
        13: return
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0      14     0  this   LTest$;
            0      14     1  args   [Ljava/lang/String;
           13       0     2 barResult   I
      LineNumberTable:
        line 16: 0
}
```

I've run this test across our active JVMs:

```
% for v in 1.6 1.7 1.8; do java_use $v; pt --terse test/files/run/t7965.scala || break; done
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-466.1-11M4716)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-466.1, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:02)
Test Run PASSED
java version "1.7.0_71"
Java(TM) SE Runtime Environment (build 1.7.0_71-b14)
Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:07)
Test Run PASSED
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:05)
Test Run PASSED
```
cbd5bb3
@retronym retronym referenced this pull request from a commit in retronym/scala
@retronym retronym SI-7965 Support calls to MethodHandle.{invoke,invokeExact}
These methods are "signature polymorphic", which means that compiler
should not:
  1. adapt the arguments to `Object`
  2. wrap the repeated parameters in an array
  3. adapt the result type to `Object`, but instead treat it as it
     it already conforms to the expected type.

Dispiritingly, my initial attempt to implement this touched the type
checker, uncurry, erasure, and the backend.

However, I realized we could centralize handling of this in the typer
if at each application we substituted the signature polymorphic
symbol with a clone that carried its implied signature, which is
derived from the types of the arguments (typechecked without an
expected type) and position within and enclosing cast or block.

The test case requires Java 7+ to compile so is currently embedded
in a conditionally compiled block of code in a run test.

We ought to create a partest category for modern JVMs so we can
write such tests in a more natural style.

Here's how this looks in bytecode. Note the `bipush` / `istore`
before/after the invocation of `invokeExact`, and the descriptor
`(LO$;I)I`.

```
% cat sandbox/poly-sig.scala && qscala Test && echo ':javap Test$#main' | qscala
import java.lang.invoke._

object O {
  def bar(x: Int): Int = -x
}

object Test {
  def main(args: Array[String]): Unit = {
    def lookup(name: String, params: Array[Class[_]], ret: Class[_]) = {
      val lookup = java.lang.invoke.MethodHandles.lookup
      val mt = MethodType.methodType(ret, params)
      lookup.findVirtual(O.getClass, name, mt)
    }
    def lookupBar = lookup("bar", Array(classOf[Int]), classOf[Int])

    val barResult: Int = lookupBar.invokeExact(O, 42)
    ()
  }
}

scala> :javap Test$#main
  public void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=2
         0: aload_0
         1: invokespecial #18                 // Method lookupBar$1:()Ljava/lang/invoke/MethodHandle;
         4: getstatic     #23                 // Field O$.MODULE$:LO$;
         7: bipush        42
         9: invokevirtual #29                 // Method java/lang/invoke/MethodHandle.invokeExact:(LO$;I)I
        12: istore_2
        13: return
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0      14     0  this   LTest$;
            0      14     1  args   [Ljava/lang/String;
           13       0     2 barResult   I
      LineNumberTable:
        line 16: 0
}
```

I've run this test across our active JVMs:

```
% for v in 1.6 1.7 1.8; do java_use $v; pt --terse test/files/run/t7965.scala || break; done
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-466.1-11M4716)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-466.1, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:02)
Test Run PASSED
java version "1.7.0_71"
Java(TM) SE Runtime Environment (build 1.7.0_71-b14)
Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:07)
Test Run PASSED
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)
Selected 1 tests drawn from specified tests

.

1/1 passed (elapsed time: 00:00:05)
Test Run PASSED
```
c1d092a
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Commits on Dec 3, 2011
  1. @ijuma

    Delegate to Java's implementation of signum for Long and Int.

    ijuma authored
    The Java implementation is faster as it doesn't have branches.
    
    java.lang.Math includes implementations of signum for Double and Float,
    but I didn't change the ones in scala.math because there is a difference
    on how negative zero is handled.
This page is out of date. Refresh to see the latest.
View
12 src/library/scala/math/package.scala
@@ -127,15 +127,9 @@ package object math {
else if (x > 0) 1.0f
else x // NaN
- def signum(x: Long): Long =
- if (x == 0l) 0l
- else if (x < 0) -1l
- else 1l
-
- def signum(x: Int): Int =
- if (x == 0) 0
- else if (x < 0) -1
- else 1
+ def signum(x: Long): Long = java.lang.Long.signum(x)
+
+ def signum(x: Int): Int = java.lang.Integer.signum(x)
// -----------------------------------------------------------------------
// root functions
View
15 test/files/jvm/signum.scala
@@ -0,0 +1,15 @@
+object Test {
+ def main(args: Array[String]) {
+ assert(math.signum(Long.MaxValue) == 1L)
+ assert(math.signum(1L) == 1L)
+ assert(math.signum(0L) == 0L)
+ assert(math.signum(-1L) == -1L)
+ assert(math.signum(Long.MinValue) == -1L)
+
+ assert(math.signum(Int.MaxValue) == 1)
+ assert(math.signum(1) == 1)
+ assert(math.signum(0) == 0)
+ assert(math.signum(-1) == -1)
+ assert(math.signum(Int.MinValue) == -1)
+ }
+}
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