GNUH8
v0403
October
1st, 2004
KPIT Cummins Infosystems Limited is now releasing GNUH8
v0403, a cross compiler tool
chain for the Renesas (formerly Hitachi) H8 series of micro
controllers.
SALIENT FEATURES:
GNUH8 v0403 is based on gcc-3.4.2 (snapshot as on 13th August 2004), binutils-2.15 (snapshot as on 17th May 2004) and newlib-1.12.0 (downloaded from CVS on 7th July 2004).
The latest patches have been applied to the gcc, binutils and newlib.
NOTE: GDBH8 v0402 can be used with GNUH8 v0403.
Please refer to the FAQ for details of the patches applied to the gcc-3.4 sources.
ABOUT GNUH8 v0403:
| Release version: | GNUH8 v0403 |
| Release Date: | 1st October 2004 |
| Platforms Supported: |
|
| Windows 9X/NT/2000/XP/ME | |
| Languages: | C, C++ |
| H8 Series: |
H8/300,
H8/300H, H8/300H Tiny Series, H8/S 26XX, H8/S 2XXX |
| Object File Formats: | ELF, COFF |
Please register at http://www.kpitgnutools.com for free technical support.
Please contact http://www.kpitgnutools.com/feedback.php for any feedback or suggestions.
CHANGES IN THIS RELEASE:
This section summarizes the major changes as compared to GNUH8 v0402.
GCC:
| 1 |
Following code gives error, "mstats.c: undefined reference to `_malloc_stats_r'" in v0402 since malloc_stats was not supported. Support has been added from v0403.
#include<stdio.h> |
| 2 | Following code produces Internal Compiler Error for
v0402 template<template<int> class T> struct A : T<0> { void foo(); template<template<int> class U> friend void A<U>::foo(); }; template<int> struct B {}; A<B> a; This has been fixed. |
| 3 | Following code gives Internal Compiler Error. void bug(char* dst) { register char* _dst __asm ("er6"); __asm__ ("eepmov.b":"=g"(*_dst)::"r4","er5","er6"); } Instead of ICE, following error is displayed, "error:asm clobber conflict with output operand" |
| 4 | Support for long long has been added for H8/300. |
| 5 | The "function_vector" attribute is modified so as to
take vector address location as location used for indirect memory addressing jump instruction like "jsr @aa:8". This was not present in earlier tool chains. Use of this attribute will save two bytes per function call but reduces speed of execution slightly. Example: void foo (void) __attribute__ ((function_vector(vector_address))); void foo (void) { } void bar (void) { foo(); } |
HEW:
| 1 | Following compiler options are added, -ffunction-sections -fdata-sections -fomit-frame-pointer |
| Following linker option is added, --gc-sections |
|
| Checkbox for KEEP is added in options->linker->sections-><section name>->Advanced similar to checkbox for NOLOAD. | |
| Disable "NOLOAD" if "KEEP" is checked and vice versa. Checkbox "KEEP" is by default checked for .vects section and for any other section, both checkboxes are in not checked position. | |
| The linker option "--gc-sections" will be ignored by COFF tool chain. Garbage collection will not be done in COFF tool chain. So, in case of COFF tool chain, linker option "--gc-sections" is grayed out in not selected position. | |
| Linker sections are modified like following, In .text section .text.* is added before etext In .data section .data.* is added before _edata |
|
| Compiler options "-fdata-sections", "-ffunction-sections" along with linker option "--gc-sections" will optimize code by removing unused variables and functions. | |
| Due to above additions, HEW project created using v0403 GNUH8 tool chain cannot be built successfully using GNUH8 v0402 and lower versions of tool chain. | |
| 2 | HEAP memory control function "sbrk()", low level read/write functions "_read()" & "_write()" are added in HEW sample projects for GNUH8 tool chain. Programmer has to modify target hardware related calls and use above mentioned functionality on target. These low level read/write functions are useful in case of redirecting "stdin"/"stdout" to serial port, LCD etc. |
| 3 | Macros DEBUG and RELEASE are added in HEW DLL in respective sessions. Call to library routine "_exit()" is done depending on those macros. The function is only called in Debug mode. This will reduce code size in Release mode by not including un-necessary _exit routine and few byte of program meory are saved. |
Samples:
| 1 | Samples of EDK2215 and EDK3069 for HEAP memory control and low level read/write are added. |
| 2 | XMK-OS is ported for EVB2623. OS source code, samples with application and readme file are included. |
| 3 | File start.S is modified such that call to library routine "_exit()" is made depending on macro DEBUG and RELEASE. |
| 4 | Macro DEBUG is added for debug mode RAM application and RELEASE is added for release mode ROM application in makefile of samples. |
Documentation:
|
Application Note on Optimization options of compiler |
|
| 1 | This note mentions about compiler behavior for various code snippets when compiled with optimization options. It also states workaround options to get expected behavior from code snippets. |
|
Renesas-GNUH8 Migration Guide |
|
| 1 | Assembler directive .align is added which is compatible with .ALIGN Renesas directive. |
| 2 | Following intrinsic functions are modified, dadd(), dsub(), mac(), rotlw() |
|
IAR-GNUH8 Migration Guide |
|
| 1 | Following intrinsic functions are modified, dadd(), dsub(), mac(), rotlw() |
Known Problems:
H8-COFF and H8-ELF:
| 1 | Windows 9X has restriction on the length of command line that can be given. Due to this, |
|
1. When the tool chain shortcut from 'Start' menu is invoked, the relevant batch file may not be found and Windows 9X may display an error. |
|
| 2. In HEW (High-performance Embedded Workshop), this restriction may cause problems during linking. | |
|
Please refer to the following link for further details on this. |
|
| 2 | Following code gives warning "will never be
executed" for " return (val);" statement in "Factorial" function with
"-O2" and "-Wunreachable-code" command line options. float foo (float X) { float val = 1.0; int k,j; for (k=1; k < 5; k++) { val += 1.0; } return (val); } |
| This can be avoided by using volatile variable in the "foo" function. | |
| 3 | GNUH8 assembler does not generate error or warning message when immediate
data in the HEX format is given with H' as prefix. For example, mov #H'0f,rl0 |
| 4 | Following code
if compiled for H8300H, H8300HN, H8S, H8300SN targets with optimization
option -O2 and above, generates wrong assembly code, unsigned int ReadWordx86Style(unsigned long lAddr) { unsigned char baBuff[2]; baBuff[0x00]=*((unsigned char *)((unsigned int)(lAddr+1))); baBuff[0x01]=*((unsigned char *)((unsigned int)(lAddr+0))); return((*(unsigned int *)baBuff)); } int start(void) { unsigned char baBuff[256]; unsigned int wResult; wResult = ReadWordx86Style((unsigned long)((unsigned int)baBuff)); return(wResult); } |
| Workaround is to pass an option -fno-expensive-optimizations along with -O2. | |
| 5 | Following code
produces Internal Compiler Error, void set_bit(int nr, char * addr) { __asm__("bset %w1,%0" :"=m"(*addr) :"g"(nr),"m"(*addr)); } |
H8-COFF:
| 1 | Following code
gives error "Too many new sections; can't add ".bss.w35"" when compiled
with -fdata-sections option, unsigned int
w00,w01,w02,w03,w04,w05,w06,w07,w08,w09,w10,w11,w12,w13,w14,w15,w16,w17,w18,w19,w20,w21,w22,w23,w24,w25,w26,w27, w28,w29,w30,w31,w32, w33,w34,w35,w36,w37,w38,w39; int main(void) { } |
| Change in variable name from w?? to ww?? removes error. |
H8-ELF:
| 1 | Following C++
code produces Internal Compiler Error if -O1 is passed with -g option, namespace N { int foo(); struct A { A(); ~A() { if (foo()) foo(); } }; struct B : A {}; struct C : B {}; struct D : C {}; struct E { D d1, d2; }; inline E bar1() { E bar2 (const E&); E e; return bar2(E()); } E e=bar1(); } |
NOTE:
| 1 | The int32 libraries for H8/300 are not provided with this release. |