Release notes for ARM Compiler toolchain 5.01u1

Enhancements in 5.01u1

Other changes

• Support has been added for the ARM Cortex-A7 processor. This can be selected with --cpu=Cortex-A7, --cpu=Cortex-A7.no_neon and --cpu=Cortex-A7.no_neon.no_vfp. [SDCOMP-317]

Corrections in 5.01u1

Assembler (armasm)

• The assembler FUNCTION and PROC directives now accept empty register lists as arguments. When an empty register list is specified, it means that all registers are caller-saved. For example, this allows a reset handler to be correctly described to a debugger. [SDCOMP-15057]

Compiler (armcc)

• When intrinsics or inline assembly were used, the compiler could generate incorrect code for handling Q or GE flags or spurious warnings: C3007E: Uninitialised or corrupted use of PSR. This is now fixed. [SDCOMP-17110]
• ARM Compiler 5.01 does not support the use of pre-compiler headers, --pch, on 64-bit Windows 7 platforms.
  [SDCOMP-17087]
• ARM Compiler 5.01 does not support the use of Cygwin on 64-bit Windows 7 platforms. [SDCOMP-17071]
• An issue in the compiler's vectorization support meant that an addition of a constant negative value in a loop could sometimes result in vector subtraction of the negative value. This has been fixed. [SDCOMP-16753]
• In certain situations, the compiler could incorrectly treat a 64bit shift as a 32bit shift and hence get incorrect results. [SDCOMP-16710]
• Static initialisers for unions containing bitfields were being ignored. This has been fixed. [SDCOMP-16604]
• The compiler could incorrectly transform a memcpy-like loop that reads the first element of the source buffer as the length in such a way that the first element of the buffer would be repeated in the destination. This has been fixed. [SDCOMP-16162]
• The compiler could sometimes incorrectly remove assignments to members of static structures with the __packed attribute and unaligned fields. This has been corrected.
  [SDCOMP-16133]
• In some cases involving indexing and negative offsets the compiler would generate inefficient code using VREV instructions when using --vectorize. This has been fixed. [SDCOMP-15561]
• The volatile keyword was not being honoured when used with template classes. This has been fixed. [SDCOMP-15067]
• When using the --arm_linux_configure option, the compiler had difficulty in some cases identifying the path to libstdc++ headers when configuring against GCC for ARM Linux, in cases where the path to the headers included a space. This has now been fixed. [SDCOMP-14594]
• The handling of state effecting pragmas has been improved. Now, #pragma push and #pragma pop save and restore the state of diagnostics pragmas.
  This will affect the severity of diagnostic messages when using #pragma diag_suppress. In order to be effective, the #pragma push and #pragma pop must enclose the full scope responsible for the generation of diagnostic message. For example, the compiler will generate a warning, Warning #177-D: variable "b" was declared but never referenced for function foo(), in only one of the following cases:
  

  
  void foo(void)
  {
    #pragma push
    #pragma diag_suppress 177
    int b;                // warning not suppressed
    #pragma pop
  }
  
  
  #pragma push
  #pragma diag_suppress 177
  void foo(void)
  {
    int b;                // warning suppressed
  }
  #pragma pop
  

  [SDCOMP-11007]

Libraries

• The C++ library function std::return_temporary_buffer could cause a small memory leak in some circumstances. This has been fixed. [SDCOMP-14105]