[avr-gcc-list] ICE in dwarf2out_frame_debug_expr()

[Boyapati, Anitha]

Hello,

I am doing a preliminary analysis for supporting call frame debugging 
information in avr. (gcc bug 17994). When I build, I am facing ICE in 
dwarf2out. Obviously the code goes to gcc_unreachable() in the big function: 
dwarf2out_frame_debug_expr(). Before I proceed further, I would like to know if 
the call-stack information presented is correct.

I am posting little about the design, patch and error. Version of gcc I am 
using is 4.4.3 (that got released with AVR Toolchain 3.0.0)


Little about design:

As per gcc internals, INCOMING_RETURN_ADDR_RTX should defined. Since AVR does 
not have link register, the resulting address should be obtained from stack 
top. I define INCOMING_RETURN_ADDR_RTX to avr_incoming_return_addr_rtx() in 
avr.h which inturn is defined in avr.c as follows:

+
+/*Call stack information. Implements INCOMING_RETURN_ADDR_RTX  
+
+    +-------------------------------+ <--- Frame Pointer(FP) for this frame
+    | local variables               |
+    |-------------------------------|
+    |caller frame's frame pointer   |
+    |-------------------------------|
+    | Return address                |
+    +-------------------------------+
+
+*/
+
+rtx
+avr_incoming_return_addr_rtx (void)
+{
+  /* Compute return address which is stored on the stack.
+     Current stack pointer at the begining of frame, before the prologue
+     execution holds the return address. So our job is done if we get
+     the stack pointer register value which inturn points to return address
+   */
+  return gen_rtx_MEM (HImode, stack_pointer_rtx);
+}
+
+


ICE Error:

<snip> ... -g -O2 -mmcu=avr25 -O2  -g -O2 -DIN_GCC -DCROSS_DIRECTORY_STRUCTURE  
-W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes -Wcast-qual 
-Wold-style-definition  -isystem ./include  -DDF=SF -Dinhibit_libc 
-mcall-prologues -Os -g  -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED -Dinhibit_libc  
-I. -I. -I../../.././gcc -I../../../../libgcc -I../../../../libgcc/. 
-I../../../../libgcc/../gcc -I../../../../libgcc/../include   -o _mulvhi3.o -MT 
_mulvhi3.o -MD -MP -MF _mulvhi3.dep -DL_mulvsi3 -c 
../../../../libgcc/../gcc/libgcc2.c  \
                -DLIBGCC2_UNITS_PER_WORD=2
../../../../libgcc/../gcc/libgcc2.c: In function '__mulvhi3':
../../../../libgcc/../gcc/libgcc2.c:165: internal compiler error: in 
dwarf2out_frame_debug_expr, at dwarf2out.c:2323
Please submit a full bug report,

Thanks
Anitha