Slow execution of large byte slice/string operations

[notJoon]

Description

The stdlibs/bytes package tests are running slowly.

Tests like TestIndexByteNearPageBoundary, TestIndexNearPageBoundary, and TestCompareBytes take particularly long. These tests all use large byte slices.

Similar slow performance was seen in the p/demo/diff package tests when using strings.Repeat to create long strings.

=== RUN   TestMyersDiff/Worst-case_scenario_(completely_different_strings)
--- PASS: TestMyersDiff/Worst-case_scenario_(completely_different_strings) (29.70s)
=== RUN   TestMyersDiff/Very_long_strings
--- PASS: TestMyersDiff/Very_long_strings (23.81s)
--- PASS: TestMyersDiff (53.55s)
ok      examples/gno.land/p/demo/diff   54.24s

I suspect the VM is doing unnecessary work when generating and manipulating large strings or byte slices.

This problem was founded on PR #2616

bytes Execution Logs

=== RUN   TestEqualNearPageBoundary
--- PASS: TestEqualNearPageBoundary (0.07s)
=== RUN   TestIndexByteNearPageBoundary
--- PASS: TestIndexByteNearPageBoundary (12.94s)
=== RUN   TestIndexNearPageBoundary
--- PASS: TestIndexNearPageBoundary (12.73s)
=== RUN   TestNewBuffer
--- PASS: TestNewBuffer (0.00s)
=== RUN   TestNewBufferString
--- PASS: TestNewBufferString (0.00s)
=== RUN   TestBasicOperations
--- PASS: TestBasicOperations (0.00s)
=== RUN   TestLargeStringWrites
--- PASS: TestLargeStringWrites (0.03s)
=== RUN   TestLargeByteWrites
--- PASS: TestLargeByteWrites (0.04s)
=== RUN   TestLargeStringReads
--- PASS: TestLargeStringReads (0.01s)
=== RUN   TestLargeByteReads
--- PASS: TestLargeByteReads (0.01s)
=== RUN   TestMixedReadsAndWrites
--- PASS: TestMixedReadsAndWrites (0.09s)
=== RUN   TestCapWithPreallocatedSlice
--- PASS: TestCapWithPreallocatedSlice (0.00s)
=== RUN   TestCapWithSliceAndWrittenData
--- PASS: TestCapWithSliceAndWrittenData (0.00s)
=== RUN   TestNil
--- PASS: TestNil (0.00s)
=== RUN   TestReadFrom
--- PASS: TestReadFrom (0.03s)
=== RUN   TestReadFromPanicReader
--- PASS: TestReadFromPanicReader (0.00s)
=== RUN   TestReadFromNegativeReader
--- PASS: TestReadFromNegativeReader (0.00s)
=== RUN   TestWriteTo
--- PASS: TestWriteTo (0.02s)
=== RUN   TestRuneIO
--- PASS: TestRuneIO (0.14s)
=== RUN   TestWriteInvalidRune
--- PASS: TestWriteInvalidRune (0.00s)
=== RUN   TestNext
--- PASS: TestNext (0.00s)
=== RUN   TestReadBytes
--- PASS: TestReadBytes (0.00s)
=== RUN   TestReadString
--- PASS: TestReadString (0.00s)
=== RUN   TestGrow
--- PASS: TestGrow (16.31s)
=== RUN   TestGrowOverflow
--- PASS: TestGrowOverflow (0.00s)
=== RUN   TestReadEmptyAtEOF
--- PASS: TestReadEmptyAtEOF (0.00s)
=== RUN   TestUnreadByte
--- PASS: TestUnreadByte (0.00s)
=== RUN   TestBufferGrowth
--- PASS: TestBufferGrowth (1.55s)
=== RUN   TestEqual
--- PASS: TestEqual (0.00s)
=== RUN   TestEqualExhaustive
--- PASS: TestEqualExhaustive (0.30s)
=== RUN   TestNotEqual
--- PASS: TestNotEqual (1.64s)
=== RUN   TestIndex
--- PASS: TestIndex (0.05s)
=== RUN   TestLastIndex
--- PASS: TestLastIndex (0.04s)
=== RUN   TestIndexAny
--- PASS: TestIndexAny (0.00s)
=== RUN   TestLastIndexAny
--- PASS: TestLastIndexAny (0.00s)
=== RUN   TestLastIndexByte
--- PASS: TestLastIndexByte (0.00s)
=== RUN   TestIndexByteBig
--- PASS: TestIndexByteBig (5.21s)
=== RUN   TestIndexByteSmall
--- PASS: TestIndexByteSmall (4.75s)
=== RUN   TestIndexRune
--- PASS: TestIndexRune (0.10s)
=== RUN   TestCountByte
--- PASS: TestCountByte (84.63s)
=== RUN   TestCountByteNoMatch
--- PASS: TestCountByteNoMatch (14.10s)
=== RUN   TestSplit
--- PASS: TestSplit (0.00s)
=== RUN   TestSplitAfter
--- PASS: TestSplitAfter (0.00s)
=== RUN   TestFields
--- PASS: TestFields (0.00s)
=== RUN   TestFieldsFunc
--- PASS: TestFieldsFunc (0.00s)
=== RUN   TestMap
--- PASS: TestMap (0.00s)
=== RUN   TestToUpper
--- PASS: TestToUpper (0.00s)
=== RUN   TestToLower
--- PASS: TestToLower (0.00s)
=== RUN   TestToValidUTF8
--- PASS: TestToValidUTF8 (0.00s)
=== RUN   TestTrimSpace
--- PASS: TestTrimSpace (0.00s)
=== RUN   TestRepeat
--- PASS: TestRepeat (0.00s)
=== RUN   TestRepeatCatchesOverflow
--- PASS: TestRepeatCatchesOverflow (0.00s)
=== RUN   TestRunes
--- PASS: TestRunes (0.00s)
=== RUN   TestTrim
--- PASS: TestTrim (0.00s)
=== RUN   TestTrimFunc
--- PASS: TestTrimFunc (0.00s)
=== RUN   TestIndexFunc
--- PASS: TestIndexFunc (0.00s)
=== RUN   TestReplace
--- PASS: TestReplace (0.00s)
=== RUN   TestTitle
--- PASS: TestTitle (0.00s)
=== RUN   TestToTitle
--- PASS: TestToTitle (0.00s)
=== RUN   TestEqualFold
--- PASS: TestEqualFold (0.00s)
=== RUN   TestBufferGrowNegative
--- PASS: TestBufferGrowNegative (0.00s)
=== RUN   TestBufferTruncateNegative
--- PASS: TestBufferTruncateNegative (0.00s)
=== RUN   TestBufferTruncateOutOfRange
--- PASS: TestBufferTruncateOutOfRange (0.00s)
=== RUN   TestContains
--- PASS: TestContains (0.00s)
=== RUN   TestContainsAny
--- PASS: TestContainsAny (0.00s)
=== RUN   TestContainsRune
--- PASS: TestContainsRune (0.00s)
=== RUN   TestCompare
--- PASS: TestCompare (0.03s)
=== RUN   TestCompareIdenticalSlice
--- PASS: TestCompareIdenticalSlice (0.00s)
=== RUN   TestCompareBytes
--- PASS: TestCompareBytes (185.59s)
=== RUN   TestEndianBaseCompare
--- PASS: TestEndianBaseCompare (1.17s)
=== RUN   TestReader
--- PASS: TestReader (0.00s)
=== RUN   TestReadAfterBigSeek
--- PASS: TestReadAfterBigSeek (0.00s)
=== RUN   TestReaderAt
--- PASS: TestReaderAt (0.00s)
=== RUN   TestReaderWriteTo
--- PASS: TestReaderWriteTo (0.00s)
=== RUN   TestReaderLen
--- PASS: TestReaderLen (0.00s)
=== RUN   TestUnreadRuneError
--- PASS: TestUnreadRuneError (0.00s)
=== RUN   TestReaderDoubleUnreadRune
--- PASS: TestReaderDoubleUnreadRune (0.00s)
=== RUN   TestReaderCopyNothing
--- PASS: TestReaderCopyNothing (0.00s)
=== RUN   TestReaderLenSize
--- PASS: TestReaderLenSize (0.00s)
=== RUN   TestReaderReset
--- PASS: TestReaderReset (0.00s)
=== RUN   TestReaderZero
--- PASS: TestReaderZero (0.00s)
ok      gnovm/stdlibs/bytes     517.89s