》KEIL C251详细介绍》

• [C251 Compiler]
• • Added: optimization for handling of 32 bit numbers.
  • Added: optimization for for functions that do never return. This functions need to use __attribute__ ((noreturn)).
  • Corrected: assembler instructions used as label name erroneously thrown an Syntax-Error in SRC mode.
  • Corrected: a potential inline-assembler macro problem with '#' when meant for the #imm operand. Example:

    #pragma SRC
    
    #define AOP         \ 
       __asm { NOP }    \ 
       __asm { MOV A,#1 }    // incorrect generated error C302: misused # operator
    
    void main (void) {
      AOP
    }
    

  • Corrected: incorrect error C143 "initializer is not a constant" generation at cast of a constant pointer which is part of a struct. Example:

    struct GlStruct {
      char a;
      char cArr[1];
    };
    
    long offset = (long) (*(struct GlStruct*)0x0D000000).cArr;   // incorrect generated error: C143 "initializer is not a constant"
    

  • Corrected: incorrect error C83 "incompatible types" generation when used floating point types togehter with & operator. Example:

     volatile unsigned long  ul2;
     volatile signed char    sc1;
     volatile signed char    sc2;
    
     void main(void) {
       ul2 = 2147483647L;
       sc1 = -1;
       sc2 = 1;
       (ul2 ^= (((( ! ( (double) (char)127))) > ((( -- sc2)))) & sc1));  // incorrect generated error C83: '&': incompatible types
     }
    

  • Corrected: huge at function definition is not allowed. Erroneously has been taken as near. Example:

    void huge hg_fnc() {  }   // The warning C65: 'hg_fnc': illegal use of near/far/huge will be generated.
    

• [L251 Linker]
• • Corrected: a potential incorrect overlap of data segments when this features are used in combination:
    • Overlapping segments by command line directives.
    • Linker Code Packing optimization with ROM (HUGE) model.
    • Code segments placed in the same 64KB region as the DATA segments.
• [A251 Assembler]
• • Added: support for forward slash (/) as path seperator.
• [C Run-Time Library]
• • Corrected: the function free failed when the complete memory pool was allocated.
  • Corrected: the HPTR variant of the function float LOG does not work.
• [μVision]
• • This C251 release is delivered with μVision V4.60.6.9 IDE.