Add the first phi's input as possible generate-at-use-site.

Add the first phi's input as possible generate-at-use-site.

May remove some extraneous temporary variables, if the values are computed
in an opportune order (read: Room for improvement).

Committed: https://code.google.com/p/dart/source/detail?r=6517

[floitsch, 2012-04-13 12:41:32]

LGTM.

https://chromiumcodereview.appspot.com/10084002/diff/1/frog/tests/leg/src/Ssa...
File frog/tests/leg/src/SsaPhiCodegenTest.dart (right):

https://chromiumcodereview.appspot.com/10084002/diff/1/frog/tests/leg/src/Ssa...
frog/tests/leg/src/SsaPhiCodegenTest.dart:68: // TODO(ngeoffray): Add live range
analysis to the codegen
Either remove comment, or add a test that actually needs the liveness analysis.

https://chromiumcodereview.appspot.com/10084002/diff/1/frog/tests/leg/src/Typ...
File frog/tests/leg/src/TypeInferenceTest.dart (right):

https://chromiumcodereview.appspot.com/10084002/diff/1/frog/tests/leg/src/Typ...
frog/tests/leg/src/TypeInferenceTest.dart:57: // TODO(ngeoffray): Do live range
analysis to make this test pass.
ditto.

https://chromiumcodereview.appspot.com/10084002/diff/1/lib/compiler/implement...
File lib/compiler/implementation/ssa/codegen_helpers.dart (right):

https://chromiumcodereview.appspot.com/10084002/diff/1/lib/compiler/implement...
lib/compiler/implementation/ssa/codegen_helpers.dart:155:
tryMergingExpressions(block.predecessors[0]);
maybe add an assert(phis.isEmpty())?

[Lasse Reichstein Nielsen, 2012-04-13 13:03:58]

https://chromiumcodereview.appspot.com/10084002/diff/1/frog/tests/leg/src/Ssa...
File frog/tests/leg/src/SsaPhiCodegenTest.dart (right):

https://chromiumcodereview.appspot.com/10084002/diff/1/frog/tests/leg/src/Ssa...
frog/tests/leg/src/SsaPhiCodegenTest.dart:68: // TODO(ngeoffray): Add live range
analysis to the codegen
Moved down to the case that is still isFalse.

https://chromiumcodereview.appspot.com/10084002/diff/1/frog/tests/leg/src/Typ...
File frog/tests/leg/src/TypeInferenceTest.dart (right):

https://chromiumcodereview.appspot.com/10084002/diff/1/frog/tests/leg/src/Typ...
frog/tests/leg/src/TypeInferenceTest.dart:57: // TODO(ngeoffray): Do live range
analysis to make this test pass.
Removed.