topic Re: IFX: LLVM ERROR: SmallVector unable to grow. in Intel® Fortran Compiler

IFX: LLVM ERROR: SmallVector unable to grow.

IVV — Fri, 23 Jan 2026 10:39:12 GMT

I'm trying to build a library for the release configuration on windows using ifx.

One file always causes the compiler to crash reporting this:

Compiling with Intel® Fortran Compiler 2025.3.2 [Intel(R) 64]...
V3MatIO.F90
LLVM ERROR: SmallVector unable to grow. Requested capacity (18446744073709551615) is larger than maximum value for size type (4294967295)
#0 0x00007ff67f32662a (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x1a4662a)
#1 0x00007ff67f326695 (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x1a46695)
#2 0x00007ff67ece06cf (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x14006cf)
#3 0x00007ff67ec6d32c (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x138d32c)
#4 0x00007ff67ee26414 (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x1546414)
#5 0x00007ff67ed31594 (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x1451594)
#6 0x00007ff67e7a0d0d (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0xec0d0d)
#7 0x00007ff67e8f2f5d (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x1012f5d)
#8 0x00007ff67e8e97ba (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x10097ba)
#9 0x00007ff67da9868b (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x1b868b)
#10 0x00007ff67ea80b83 (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x11a0b83)
#11 0x00007ff67dc49c6b (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x369c6b)
#12 0x00007ff67de4b6fb (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x56b6fb)
#13 0x00007ff67de4b011 (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x56b011)
#14 0x00007ff67df1166d (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x63166d)
#15 0x00007ff67df11084 (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x631084)
#16 0x00007ff67df10de1 (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x630de1)
#17 0x00007ff67df1166d (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x63166d)
#18 0x00007ff67f28425c (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x19a425c)
#19 0x00007ff67f282b42 (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x19a2b42)
#20 0x00007ff67efe026b (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x170026b)
#21 0x00007ff67e05a593 (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x77a593)
#22 0x00007ff67ecdb600 (C:\PROGRA~2\Intel\oneAPI\compiler\2025.3\bin\compiler\xfortcom.exe+0x13fb600)
#23 0x00007ff964d1e8d7 (C:\WINDOWS\System32\KERNEL32.DLL+0x2e8d7)
#24 0x00007ff965fcc53c (C:\WINDOWS\SYSTEM32\ntdll.dll+0x8c53c)
C:\Users\obe\AppData\Local\Temp\301646.i90: error #5629: **Internal compiler error: abort signal raised** Please report this error along with the circumstances in which it occurred in a Software Problem Report. Note: File and line given may not be explicit cause of this error.
compilation aborted for C:\Development\ivv\T3.Venus\IVV.VENUS\IVV.VENUS.Matrix.Native\V3Mat\V3MatIO.F90 (code 3)

The comiler is invoked using this statement:

ifx /nologo /O2 /assume:buffered_io /fpp /DUSEZLIB /Dx64 /warn:all /align:rec2byte /align:commons /align:sequence /Qinit:zero /module:"x64\Release\\" /object:"x64\Release\\" /libs:static /threads /c /Qlocation,link,"C:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Tools\MSVC\14.44.35207\bin\HostX64\x64" /Qm64 "C:\Development\ivv\T3.Venus\IVV.VENUS\IVV.VENUS.Matrix.Native\V3Mat\V3MatIO.F90"

The debug configuration compiles fine. If I disable optimization (/Od instead of /O2), the release configuration compiles as well.

System: Windows 11 Pro (25H2)

Compiler: Intel Fortran Essentials 2025.3.2

Re: IFX: LLVM ERROR: SmallVector unable to grow.

Stef67 — Wed, 08 Apr 2026 18:52:21 GMT

I am facing the same problem. I am honestly quite surprised no one from Intel answered your question? Is there anybody out there?

Re: IFX: LLVM ERROR: SmallVector unable to grow.

JohnNichols — Wed, 08 Apr 2026 20:36:54 GMT

There is just not enough information to help. Supply a simple Fortran file that can be tested.

Is my simple suggestion, plus this board has been quiet for months.

Re: IFX: LLVM ERROR: SmallVector unable to grow.

JohnNichols — Wed, 08 Apr 2026 20:38:19 GMT

My apologies I missed the file I will try it.

Re: IFX: LLVM ERROR: SmallVector unable to grow.

JohnNichols — Wed, 08 Apr 2026 20:52:52 GMT

I tried it, it threw 31 errors, but you could set it up with all the bells and whistles and zip file it, it is asking for things I cannot find in your file.

Re: IFX: LLVM ERROR: SmallVector unable to grow.

witwald — Wed, 08 Apr 2026 21:18:17 GMT

The error message includes:

Requested capacity (18446744073709551615) is larger than maximum value for size type (4294967295)

@IVV In case it helps, the number 18446744073709551615 = 2^64 - 1, while the number 4294967295 = 2^32 - 1. You could try commenting out large sections of the Fortran code to try and isolate which area is causing the issue. The code appears to use recursive functions, so maybe one of those is the cause of the issue.

Re: IFX: LLVM ERROR: SmallVector unable to grow.

witwald — Wed, 08 Apr 2026 21:20:22 GMT

@IVV If we are to try and test this on our own systems to try and help, then the full suite of source code should be supplied, if that is at all possible.

Re: IFX: LLVM ERROR: SmallVector unable to grow.

andrew_4619 — Thu, 09 Apr 2026 07:53:28 GMT

An internal compiler error (ICE) is a compiler bug, even with bad source it should not crash. You note to post source that reproduces the problem, the source posted seems to have a load of other dependencies. Your evaluation suggests it is optimisation that triggers the error but I would strip out those align and qinit options one a t a time to see if those are part of the trigger.

Re: IFX: LLVM ERROR: SmallVector unable to grow.

Stef67 — Thu, 09 Apr 2026 12:46:43 GMT

We found the root cause on our side.

In a call like:

CALL SubA(obj, SubB, unit, ierr)

the second argument was intended to be the name of the calling routine, so it should have been passed as a character literal:

CALL SubA(obj, "SubB", unit, ierr)

Without the quotation marks, SubB is interpreted as an identifier (a procedure name) instead of a string. After adding the quotes, the Release build with IFX succeeds.

That said, IFX 2025.3.2 (Release configuration) was not issuing a diagnostic for this invalid argument and instead failed with:

LLVM ERROR: SmallVector unable to grow

For reference, IFORT compiled the same source without complaint.

So while the source was incorrect, this still appears to be a robustness issue in IFX, since an invalid argument should normally produce a clear compiler error rather than an internal compiler failure.

Re: IFX: LLVM ERROR: SmallVector unable to grow.

JohnNichols — Thu, 09 Apr 2026 16:28:36 GMT

I am glad you found and reported the error. At least this site will attempt to answer your questions, you should try some of the other sites I am on.

If you want to know pain, try Microsoft Fortran PowerStation that is a grandfather to IFX, then you knew true pain.

If you want lousy error messages, try AutoCAD DXF reader, sorry, there are no message, one has to search in the DXF file. And only VEDIT will open such a file, many years of personal experience. VEDIT is the best as it shows crud in files no other editor does not.

MSVS this morning has been filling in my output statements, it is like it thinks faster than I can, right it can.

This should be zero if all bytes are accounted for! ::

This is the correct message, MSVS got it in a millisecond, I had to read it.

So good work and splice the main brace.

Re: IFX: LLVM ERROR: SmallVector unable to grow.

andrew_4619 — Fri, 10 Apr 2026 14:42:22 GMT

did you have an explicit interface or the check interfaces option? The compiler might not otherwise be able to see the interface error.

Re: IFX: LLVM ERROR: SmallVector unable to grow.

Igor_V_Intel — Tue, 14 Apr 2026 15:03:27 GMT

I have tried to create a simple reproducer, but it did NOT trigger the LLVM crash, e.g.

module V3MatType implicit none type :: T_MATRIX integer :: iODCount integer :: iFlags integer :: hWnd end type T_MATRIX integer, parameter :: gc_FlagOrigin = 1 end module V3MatType module V3Mat use V3MatType implicit none contains logical function Init(pMat, size, flags) type(T_MATRIX), pointer :: pMat integer, intent(in) :: size, flags Init = .true. end function subroutine V3RaiseStatus(hWnd, msg) integer, intent(in) :: hWnd character(len=*), intent(in) :: msg print *, msg end subroutine end module V3Mat module V3MatIO use V3MatType use V3Mat implicit none contains ! External function that expects a string for the caller name logical(4) function V3FileTest(flags, filename, caller_info) integer(4), intent(in) :: flags character(len=*), intent(in) :: filename character(len=*), intent(in) :: caller_info ! Should be a string! print *, 'V3FileTest called from: ', trim(caller_info) V3FileTest = .true. end function V3FileTest ! This function demonstrates the CORRECT pattern logical(2) recursive function V3MatRead_Correct(cFile, pMat) character(len=*) :: cFile type(T_MATRIX), pointer :: pMat logical(4) :: V3FileTest logical(4) :: lRet external :: V3FileTest V3MatRead_Correct = .false. ! CORRECT - using string literal with quotes if (.not. V3FileTest(ior(2, 4), cFile, 'V3MatRead_Correct( cFile, pMat )')) return nullify(pMat) lRet = Init(pMat, 0, gc_FlagOrigin) V3MatRead_Correct = .true. end function V3MatRead_Correct ! This function demonstrates the BUGGY pattern logical(2) recursive function V3MatRead_Buggy(cFile, pMat) character(len=*) :: cFile type(T_MATRIX), pointer :: pMat logical(4) :: V3FileTest logical(4) :: lRet external :: V3FileTest V3MatRead_Buggy = .false. ! BUG: V3MatRead_Buggy should be a quoted string! ! This passes the function name instead of a string if (.not. V3FileTest(ior(2, 4), cFile, V3MatRead_Buggy)) return nullify(pMat) lRet = Init(pMat, 0, gc_FlagOrigin) V3MatRead_Buggy = .true. end function V3MatRead_Buggy ! Another buggy variant logical(2) recursive function V3MatWrite_Buggy(pMat, cFile) type(T_MATRIX), pointer :: pMat character(len=*) :: cFile logical(4) :: v3FileTest external :: V3FileTest V3MatWrite_Buggy = .false. ! BUG: V3MatWrite_Buggy without quotes if (.not. V3FileTest(ior(1, 4), cFile, V3MatWrite_Buggy)) return V3MatWrite_Buggy = .true. end function V3MatWrite_Buggy ! Complex scenario with multiple buggy calls logical(2) recursive function CMaToV3Mat_Buggy(cFile, pMat) character(len=*) :: cFile type(T_MATRIX), pointer :: pMat logical(4), external :: V3FileTest logical(2) :: lRet character(len=300) :: cStatus lRet = .false. ! BUG: CMaToV3Mat_Buggy without quotes if (.not. V3FileTest(ior(2, 4), cFile, CMaToV3Mat_Buggy)) return nullify(pMat) lRet = Init(pMat, 100, gc_FlagOrigin) write(cStatus, '(a,a,a)') 'Reading CMA matrix ', cFile, ' ...' call V3RaiseStatus(pMat%hWnd, trim(cStatus)) ! Another buggy call pattern if (.not. V3FileTest(ior(1, 4), cFile, CMaToV3Mat_Buggy)) return lRet = .true. end function CMaToV3Mat_Buggy end module V3MatIO program test_reproducer use V3MatIO implicit none type(T_MATRIX), pointer :: pMat logical(2) :: result ! Test correct version - should work result = V3MatRead_Correct('test.mv3', pMat) ! Test buggy versions - may crash IFX during compilation result = V3MatRead_Buggy('test.mv3', pMat) result = V3MatWrite_Buggy(pMat, 'output.mv3') result = CMaToV3Mat_Buggy('test.cma', pMat) end program test_reproducer

It looks like the bug requires additional context from module dependencies and it is not possible to proceed further with no dependent modules. Since the optimizer is involved it is really sensitive to any modifications in the code.