extract_fixed_bit_field() and extract_split_bit_field() infinite recursive call

[ftwilliam]

Please, would you know what would cause an infinite recursive call of
extract_fixed_bit_field() and extract_split_bit_field();

Please, see below gdb backtrace: I set a breakpoint at
extract_fixed_bit_field() so to catch where the recursion started and
had it run for 2 recursions only before generating the backtrace:

(gdb) bt
#0  extract_fixed_bit_field (tmode=SImode, op0=0xb71b45b0, bitsize=23,
bitnum=0, target=target@entry=0x0, unsignedp=unsignedp@entry=1) at
../../gcc-repo/gcc/expmed.c:1835
#1  0x083677d9 in extract_split_bit_field (op0=op0@entry=0xb71b45b0,
bitsize=<optimized out>, bitpos=0, unsignedp=unsignedp@entry=1) at
../../gcc-repo/gcc/expmed.c:2007
#2  0x08367d29 in extract_fixed_bit_field (tmode=SImode,
op0=0xb71b45b0, bitsize=23, bitnum=0, target=target@entry=0x0,
unsignedp=unsignedp@entry=1) at ../../gcc-repo/gcc/expmed.c:1845
#3  0x083677d9 in extract_split_bit_field (op0=op0@entry=0xb71b45b0,
bitsize=<optimized out>, bitpos=0, unsignedp=unsignedp@entry=1) at
../../gcc-repo/gcc/expmed.c:2007
#4  0x08367d29 in extract_fixed_bit_field (tmode=SImode,
op0=0xb71b45b0, bitsize=23, bitnum=0, target=target@entry=0x0,
unsignedp=unsignedp@entry=1) at ../../gcc-repo/gcc/expmed.c:1845
#5  0x083677d9 in extract_split_bit_field (op0=op0@entry=0xb71b45b0,
bitsize=<optimized out>, bitpos=0, unsignedp=unsignedp@entry=1) at
../../gcc-repo/gcc/expmed.c:2007
#6  0x08367d29 in extract_fixed_bit_field (tmode=SImode,
op0=op0@entry=0xb71b45b0, bitsize=23, bitnum=0,
target=target@entry=0xb71aba60, unsignedp=unsignedp@entry=1) at
../../gcc-repo/gcc/expmed.c:1845
#7  0x08368545 in extract_bit_field_1
(str_rtx=str_rtx@entry=0xb71b45b0, bitsize=<optimized out>, bitnum=0,
unsignedp=unsignedp@entry=1, target=target@entry=0xb71aba60,
mode=mode@entry=SImode,
    tmode=tmode@entry=SImode, fallback_p=fallback_p@entry=true) at
../../gcc-repo/gcc/expmed.c:1763
#8  0x08368aad in extract_bit_field (str_rtx=0xb71b45b0, bitsize=23,
bitnum=0, unsignedp=1, target=target@entry=0xb71aba60,
mode=mode@entry=SImode, tmode=tmode@entry=SImode)
    at ../../gcc-repo/gcc/expmed.c:1819
#9  0x0837a64f in expand_expr_real_1 (exp=0xb7162af0,
target=<optimized out>, tmode=VOIDmode, modifier=EXPAND_NORMAL,
alt_rtl=0x0, inner_reference_p=false) at
../../gcc-repo/gcc/expr.c:10400
#10 0x0837d04f in expand_expr_real_1 (exp=0xb718d8c0,
target=<optimized out>, tmode=VOIDmode, modifier=EXPAND_NORMAL,
alt_rtl=0x0, inner_reference_p=false) at
../../gcc-repo/gcc/expr.c:9557
#11 0x0838edb7 in expand_expr (modifier=EXPAND_NORMAL, mode=VOIDmode,
target=0xb71aba60, exp=0xb718d8c0) at ../../gcc-repo/gcc/expr.h:254
#12 expand_expr_real_2 (ops=ops@entry=0xbf8ee998, target=0xb71aba60,
tmode=SImode, modifier=modifier@entry=EXPAND_NORMAL) at
../../gcc-repo/gcc/expr.c:8242
#13 0x08283662 in expand_gimple_stmt_1 (stmt=0xb716e540) at
../../gcc-repo/gcc/cfgexpand.c:3437
#14 expand_gimple_stmt (stmt=stmt@entry=0xb716e540) at
../../gcc-repo/gcc/cfgexpand.c:3497
#15 0x08285bd3 in expand_gimple_basic_block (bb=0xb7109d80,
disable_tail_calls=disable_tail_calls@entry=false) at
../../gcc-repo/gcc/cfgexpand.c:5509
#16 0x08287a87 in (anonymous namespace)::pass_expand::execute
(this=0x990e9e8, fun=0xb7077064) at
../../gcc-repo/gcc/cfgexpand.c:6128
#17 0x08600662 in execute_one_pass (pass=pass@entry=0x990e9e8) at
../../gcc-repo/gcc/passes.c:2317
#18 0x08600b66 in execute_pass_list_1 (pass=0x990e9e8,
pass@entry=0x990c8a8) at ../../gcc-repo/gcc/passes.c:2370
#19 0x08600bbc in execute_pass_list (fn=0xb7077064, pass=0x990c8a8) at
../../gcc-repo/gcc/passes.c:2381
#20 0x082b8096 in cgraph_node::expand (this=this@entry=0xb71740dc) at
../../gcc-repo/gcc/cgraphunit.c:1895
#21 0x082b9a03 in expand_all_functions () at
../../gcc-repo/gcc/cgraphunit.c:2031
#22 symbol_table::compile (this=this@entry=0xb7077000) at
../../gcc-repo/gcc/cgraphunit.c:2384
#23 0x082bb7af in symbol_table::finalize_compilation_unit
(this=0xb7077000) at ../../gcc-repo/gcc/cgraphunit.c:2461
#24 0x08142ffd in c_write_global_declarations () at
../../gcc-repo/gcc/c/c-decl.c:10797
#25 0x0868fb32 in compile_file () at ../../gcc-repo/gcc/toplev.c:608
#26 0x08123053 in do_compile () at ../../gcc-repo/gcc/toplev.c:2076
#27 toplev::main (this=this@entry=0xbf8eecfe, argc=argc@entry=49,
argv=argv@entry=0xbf8eeda4) at ../../gcc-repo/gcc/toplev.c:2174
#28 0x08123a2d in main (argc=49, argv=0xbf8eeda4) at
../../gcc-repo/gcc/main.c:39