• Important information
• New features
• Known problems
• Program corrections
• User documentation corrections
• Miscellaneous
• Release history

Important information

• To avoid the space-consuming tables used for character classification (ctype.h), define the preprocessor symbol __NO_CTYPE_TABLES before the ctype.h file is included.

• The compiler now avoids the LDRD instruction with the base register in list when generating code for Cortex-M3. This is to work around the Cortex-M3 erratum 602117.

• In EWARM 6.10.2:
  

  The --guard_calls command line option is introduced. Note, --guard_calls must always be used in applications written in EC++/C++ that need thread-safe library function calls. For more information, see DLIB multi-threaded support.

  The --no_guard_calls command line option is removed.

  The --aeabi command line option has modified behavior: Guard calls are not used by default.
  Migration instructions from IAR C/C++ Compiler for ARM 5.x and 6.10.1 to IAR C/C++ Compiler for ARM 6.10.2:
  --aeabi (without --no_guard_calls) shall be replaced with --aeabi --guard_calls
--aeabi --no_guard_calls shall be replaced with --aeabi
  

New features

• The product now uses the current C standard defined in 1999, known as C99, as the default C language. The previous major version of the product used the former C standard defined in 1989, known as C89. C89 can still be used in the compiler by using the --c89 option. The product will not be totally backwards-compatible though, because the support for some C99 features has been withdrawn. Variable length arrays, VLAs, in C99, are not supported in the default C language. They can be enabled with the option --vla. The C library supports all C99 functionality, and more, but only if used with the C99 language or with any C++ language. If used with the C89 language, C99-added functionality will not be allowed.

• The implementation of EC++ and EEC++ has not changed in any major way.

• Support for the C++ language has been added. By default, it fully supports the 2003 C++ standard, but can be used with exceptions and/or runtime type information disabled by using --no_exceptions and --no_rtti respectively.

• Thread-safe libraries
  The DLIB library now supports being used in a threaded environment. Some library systems, like the heap and the file structure, will be guarded by locks. Other library systems, like locale and errno, will have their static data allocated in thread-local storage. The DLIB thread support can either be supported by your chosen RTOS or can be manually implemented. For more information, see DLIB multi-threaded support.

• The compiler and assembler now automatically know where the library's system headers reside. You can control the compiler using the options:

  • --dlib_config, to choose a configuration in the DLIB library.
  • --system_include_dir, to override the directory to use as system header base.
  • --no_system_include, to turn the automation off.

• The compiler can now optimize some floating-point expressions more agressively by using the option --relaxed_fp. If enabled, the compiler tries to reduce the floating-point type used in floating-point expressions. This can cause a small loss of accuracy.

Known problems

• If your code contains hundreds of global variables and you compile it at a high optimization level, the compilation time might be very long.
  [EW14199]

• Special function registers (SFRs) declared as write-only in the header files included with the product are not treated as such by the compiler. The generated code may incorrectly use read-modify-writeback sequences.
  [EW14302]

• The C/C++ library header file time.h declares the library function mktime. When called with a negative value in the broken-down time component tm_isdst, which is part of the tm struct function parameter, mktime fails to determine whether Daylight Saving Time is active for the specified time or not.
  [EW14632]

Program corrections

• The library function fpclassify() handles normal and subnormal numbers correctly.
  [EW21098]

• Small memcpy calls are no longer transformed to assignments unless both the source and destination addresses have correct alignment.
  [EW21193]

• The compiler now checks that different kinds of variables are no placed in the same section.
  [EW21351]

• An internal error should no longer occur if __segment_begin() or __segment_end() is used in conditional code.
  [EW21770, EW21838]

• Loops that decremented an unsigned loop counter past zero could in some cases be incorrectly optimized.
  [EW21795]

• Now all system headers do not generate MISRA errors.
  [EW21799]

• When optimizing, the the compiler now handles an initializer containing a function pointer with an offset.
  [EW21870]

• The endian attribute is not supported for pointers or arrays. Now an endian attribute can no longer be specified for pointers or arrays.
  [EW21887]

• Reversal of byte order is now correctly performed also for combinations of endian attributes and unaligned accesses. Previously, this was in some cases not handled.
  [EW21888]

• At optimization level High, speed-optimizing small loops similar to

  
        int test(int n)
        {
          while (n-- > 0)
            if (!foo(n))
              break;
          return n;
        }
        

  could in some cases be incorrectly unrolled and cause an internal error.
  [EW21949]

• A class with a member that is a nameless struct, or an array of nameless structs, where at least one of the members is not a PoD, could cause an internal error while compiling.
  [EW21958]

• A while loop with a preincrement or predecrement in the loop test could be incorrectly optimized if the final part of the loop body was a do loop.
  [EW21999]

• The compiler will no longer merge instruction sequences (through cross call or cross jump optimizations) that are not equal, due to the register operand of a Thumb-2 compare-and-branch instruction (CBZ or CBNZ).
  [EW22000]

• When an enum is specified as a parameter or return type before it has been defined, the compiler will no longer record the wrong num size (attribute Tag_ABI_enum_size) in the ELF file.
  [EW22013]

• In Thumb-2, the compiler no longer issues an internal error in an attempt to widen MULS.N to MULS.W (which is not a Thumb-2 instruction) to achieve a 4-byte alignment of a following instruction or label.
  [EW22018]

• The compiler can now handle a function symbol as an argument to compiler optimized functions like memcpy.
  [EW22052]

• In EWARM 6.10.2:
  Nested for loops where the inner loop's initial or final value was the outer loop's variable, multiplied with a constant scaling factor or with a constant offset, no longer causes an internal error on high optimization.
  [EW22078]

• In EWARM 6.10.2:
  Some while loops with multiple exits no longer causes an internal error on high optimization.
  [EW22080]

• In EWARM 6.10.2:
  Constant data is now placed in the .rodata section if the compiler has not generated a direct ADR reference. If there is an ADR reference, the constant data is placed in the .text section.
  [EW22081]

• In EWARM 6.10.2:
  Standard C++ is now enabled also for the kickstart products.
  [EW22089]

• In EWARM 6.10.2:
  Now the MISRA-C:2004 rule 20.2 checker can handle a long preprocessor symbol define.
  [EW22117]

• In EWARM 6.10.2:
  For Cortex-M3, the compiler no longer attempts to generate a sub-routine for identical instruction sequences (cross-call) that end with a call to a software interrupt function (SWI), which would result in an internal error.
  [EW22118]

• In EWARM 6.10.2:
  The compiler no longer removes code that uses the result of an STREX instruction (the instruction can be generated by using the __STREX intrinsic function).
  [EW22119]

• In EWARM 6.10.2:
  The compiler no longer uses a signed 16-bit value as the immediate operand for the MOVT instruction. A 16-bit unsigned value is used instead, because MOVT expects an immediate value between 0 and 65535.
  [EW22121]

• In EWARM 6.10.2:
  Evaluating a function address without using the result no longer causes an internal error.
  [EW22146]

User documentation corrections

None.

Miscellaneous

• Generate workarounds for hardware problems:

  • Functional problem Core.1 in NXP device LPC2478: Incorrect update of the Abort Link register in Thumb state.
    Workaround generated with iccarm --enable_hardware_workaround=NXP_Core.1

Release history

See iccarm_history.ENU.html.

Copyright © 1999-2011 IAR Systems AB.