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author | Paul Phillips <paulp@improving.org> | 2011-07-04 20:40:05 +0000 |
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committer | Paul Phillips <paulp@improving.org> | 2011-07-04 20:40:05 +0000 |
commit | 257a7e65deb01c9e161c83ea5fd7a2b3c862e5e1 (patch) | |
tree | bccde9a93d807606c604ba898968316ff61fbaf5 /test/files/pos/inliner2.scala | |
parent | 9e7d7e021cd49851257aca44b81e20427d886529 (diff) | |
download | scala-257a7e65deb01c9e161c83ea5fd7a2b3c862e5e1.tar.gz scala-257a7e65deb01c9e161c83ea5fd7a2b3c862e5e1.tar.bz2 scala-257a7e65deb01c9e161c83ea5fd7a2b3c862e5e1.zip |
Fixed a bug in the optimizer which was preventi...
Fixed a bug in the optimizer which was preventing private methods from
being inlined. Also relaxes a condition related to the "liftedTry"
problem: the inliner has to exclude certain methods from consideration
if there is a value on the stack and the method being inlined has
exception handlers. The new condition is as before, except that it does
not exclude methods of the "try/finally" variety (i.e. finalizers, but
no other exception handlers.) This is necessary to optimize this common
pattern:
@inline private def foo(body: => Unit) {
val saved = something
try body
finally something = saved
}
The closure for "body" can be fully eliminated, but only if the contents
of foo can be inlined into the caller.
Closes #4764, review by rompf.
Diffstat (limited to 'test/files/pos/inliner2.scala')
-rw-r--r-- | test/files/pos/inliner2.scala | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/test/files/pos/inliner2.scala b/test/files/pos/inliner2.scala new file mode 100644 index 0000000000..bc83e04312 --- /dev/null +++ b/test/files/pos/inliner2.scala @@ -0,0 +1,57 @@ +// This isn't actually testing much, because no warning is emitted in versions +// before the fix which comes with this because the method isn't even considered +// for inlining due to the bug. +class A { + private var debug = false + @inline private def ifelse[T](cond: => Boolean, ifPart: => T, elsePart: => T): T = + if (cond) ifPart else elsePart + + final def bob1() = ifelse(debug, 1, 2) + final def bob2() = if (debug) 1 else 2 +} +// Cool: +// +// % ls -1 /tmp/2901/ +// A$$anonfun$bob1$1.class +// A$$anonfun$bob1$2.class +// A$$anonfun$bob1$3.class +// A.class +// % ls -1 /tmp/trunk +// A.class +// +// Observations: +// +// (1) The inlined version accesses the field: the explicit one calls the accessor. +// (2) The inlined version fails to eliminate boxing. With reference types it emits +// an unneeded checkcast. +// (3) The private var debug is mangled to A$$debug, but after inlining it is never accessed +// from outside of the class and doesn't need mangling. +// (4) We could forego emitting bytecode for ifelse entirely if it has been +// inlined at all sites. +// +// Generated bytecode for the above: +// +// public final int bob1(); +// Code: +// Stack=1, Locals=1, Args_size=1 +// 0: aload_0 +// 1: getfield #11; //Field A$$debug:Z +// 4: ifeq 14 +// 7: iconst_1 +// 8: invokestatic #41; //Method scala/runtime/BoxesRunTime.boxToInteger:(I)Ljava/lang/Integer; +// 11: goto 18 +// 14: iconst_2 +// 15: invokestatic #41; //Method scala/runtime/BoxesRunTime.boxToInteger:(I)Ljava/lang/Integer; +// 18: invokestatic #45; //Method scala/runtime/BoxesRunTime.unboxToInt:(Ljava/lang/Object;)I +// 21: ireturn +// +// public final int bob2(); +// Code: +// Stack=1, Locals=1, Args_size=1 +// 0: aload_0 +// 1: invokevirtual #48; //Method A$$debug:()Z +// 4: ifeq 11 +// 7: iconst_1 +// 8: goto 12 +// 11: iconst_2 +// 12: ireturn |