[vm] OSR missing phis

[dcharkes]

/===========================================================================================\
| ffi_2/inline_array_multi_dimensional_test is new and failed (RuntimeError, expected Pass) |
\===========================================================================================/

--- Command "vm" (took 01.000672s):
DART_CONFIGURATION=ReleaseX64 out/ReleaseX64/dart --optimization-counter-threshold=5 --random-seed=1974046516 --ignore-unrecognized-flags --packages=/b/s/w/ir/.packages /b/s/w/ir/tests/ffi_2/inline_array_multi_dimensional_test.dart

exit code:
255

stderr:
Unhandled exception:
Expect.equals(at index 38: Expected <...([[[[[0, 1], [2, 3]], [[4, 5], [6, 7]]], [[[8, 9], [10, 11]], [[12, 13], [14, 15]]]], [[[[16, 17], [18, 19]], [[20, 21], [22, 23]]], [[[24, 25], [26, 27]], [[28, 29], [30, 31]]]]])...>, Found: <...([[[[[0, 1], [2, 3]], [[4, 5], [6, 7]], [[8, 9], [10, 11]], [[12, 13], [14, 15]], [[16, 17], [18, 19]], [[20, 21], [22, 23]], [[24, 25], [26, 27]], [[28, 29], [30, 31]]], [], [], []], []])...>) fails.
#0      Expect._fail (package:expect/expect.dart:702:5)
#1      Expect.equals (package:expect/expect.dart:127:9)
#2      testToString (file:///b/s/w/ir/tests/ffi_2/inline_array_multi_dimensional_test.dart:141:10)
#3      main (file:///b/s/w/ir/tests/ffi_2/inline_array_multi_dimensional_test.dart:20:3)
#4      _delayEntrypointInvocation.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:283:19)
#5      _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:184:12)

--- Re-run this test:
python tools/test.py -n dartk-optcounter-linux-release-x64 ffi_2/inline_array_multi_dimensional_test

looks like some index calls are not happening: , [], [], []], []]).

https://dart-ci.appspot.com/log/any/dartk-optcounter-linux-release-x64/12076/ffi_2/inline_array_multi_dimensional_test

[dcharkes]

Non-ffi regress test: https://dart-review.googlesource.com/c/sdk/+/196320/2/tests/language/vm/regress_45260_test.dart

Expected result:

const expectedList = [
  [
    [
      [0, 1],
      [2, 3]
    ],
    [
      [4, 5],
      [6, 7]
    ]
  ],
  [
    [
      [8, 9],
      [10, 11]
    ],
    [
      [12, 13],
      [14, 15]
    ]
  ]
];

Actual result:

const expectedList = [
  [
    [
      [0, 1],
      [2, 3]
    ],
    [
      [4, 5],
      [6, 7]
    ],
    [ // The add of this sublist is to the wrong surrounding list.
      [8, 9],
      [10, 11]
    ],
    [ // The add of this sublist is to the wrong surrounding list.
      [12, 13],
      [14, 15]
    ]
  ],
  [] // They should have been added to this list.
];

The StoreLocal to :var1 in B3 is not picked up by the LoadLocal in B5 after OSR.

Unoptimized IL gist.

Optimized OSR IL gist.

Optimized non-OSR IL gist, renamed variables to match OSR IL.

The add methods are invoked on the wrong list because only the OSR param holding the at-the-OSR-time t1 stack variable flows into the add. The definition from the new list for :var1 from B3 and loaded in B5 is never seen in B12 because B12 does not have a phi for t1 and consequently always reads the original t1 from the OSR-entry.

The synthetic phis inserted for the OSR entry are only inserted for the first join after the OSR entry. This is wrong, we should have had a phi in B12 for the t1 stack variable.

Image of the various IL graphs (blue is unoptimized, and optimized non-OSR, gray is optimized OSR):