[Bug c/22565] New: GCC 3.4.1 Complex cast error in a kernel module compilation

["erwann dot houzay at laposte dot net" <gcc-bugzilla@gcc.gnu.org>]

I've found the following bug compiling the c code below: 
 
/root/Interface_thread_buffered/RTAI_GYRO.c: In function `fill_data_gyro': 
/root/Interface_thread_buffered/RTAI_GYRO.c:68: error: unrecognizable insn: 
(insn:HI 87 86 88 0 (set (reg:DF 112) 
        (float:DF (reg:HI 113))) -1 (insn_list 86 (nil)) 
    (expr_list:REG_DEAD (reg:HI 113) 
        (nil))) 
/root/Interface_thread_buffered/RTAI_GYRO.c:68: internal compiler error: in 
extract_insn, at recog.c:2083 
Please submit a full bug report, 
with preprocessed source if appropriate. 
 
The "fill_data_gyro" function contain the following code: 
 
int fill_data_gyro(unsigned char *buf, double *angle){ 
	unsigned char c; 
	unsigned char R[2]; 
	 
	char cs;              //CheckSum recupere  
	unsigned char cs_add; //Checkum calcule 
	 
	//Constantes constructeur 
	double LSB_Angle=0.000305; 
 
	----------- 
 
	R[1] = (buf[5]<<6) | (buf[6]>>1);       //c=R15-----R8 
        cs_add+=R[1] & 0xff ; 
	 
	R[0] = buf[6]<<7 | buf[7];  //c=R7-----R0 
	cs_add+=R[0] & 0xff; 
 
	* angle= -LSB_Angle * (* (short *) &R); 
		 
	----------- 
 
	return 0; 
} 
 
Commenting the "* angle= -LSB_Angle * (* (short *) &R);" the complilation work 
perfectly 
 
The makefile is the following: 
 
SOURCES  = RTAI_GYRO.c 
 
obj-m	:= $(SOURCES:.c=.o) 
RTAI     = /usr/realtime 
EXTRA_CFLAGS   = -I$(RTAI)/include -I/usr/include/ 
KDIR	:= /lib/modules/$(shell uname -r)/build 
PWD	:= $(shell pwd) 
 
 
default: 
	$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules 
 
(it's a kernel module for RTAI...) 
 
I've compiled this code inside an other application and it works perfectly 
even with the "* angle= -LSB_Angle * (* (short *) &R);" line... 
 
The gcc options associated: gcc -Wall -g -lm .... 
 
I'm a neaby in Linux and it's possible that this kind of cast (* (short *) &R) 
is not very clear for the compiler (....the star represents alternatively a 
pointeur and the multiplication symbol...) 
 
I hope not to report a know bug... 
 
My system is a Mdk 10.1 with a 2.6.7 kernel from kernel.org....(I need a 
standard kernel for RTAI developping....)  
 
bye 
 
Erwann

-- 
           Summary: GCC 3.4.1 Complex cast error in a kernel module
                    compilation
           Product: gcc
           Version: 3.4.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: erwann dot houzay at laposte dot net
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22565