https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108988
--- Comment #1 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Replacement stmt is created here:
(gdb) bt
#0 gimple_set_op (gs=<gimple_call 0x7fffea8183f0>, i=1, op=<addr_expr
0x7fffea7fa6a0>) at ../../src/gcc/gimple.h:2629
#1 0x0000000001093a6f in gimple_build_call_1 (fn=<addr_expr 0x7fffea7fa6a0>,
nargs=4) at ../../src/gcc/gimple.cc:234
#2 0x0000000001093bfd in gimple_build_call (fn=<function_decl 0x7fffea771500
__builtin_fwrite>, nargs=4) at ../../src/gcc/gimple.cc:270
#3 0x00000000010b1a0b in gimple_fold_builtin_fputs (gsi=0x7fffffffd740,
arg0=<addr_expr 0x7fffea7fa4e0>, arg1=<var_decl 0x7fffea652d80 fp>,
unlocked=false) at ../../src/gcc/gimple-fold.cc:2993
#4 0x00000000010b884f in gimple_fold_builtin (gsi=0x7fffffffd740) at
../../src/gcc/gimple-fold.cc:5060
#5 0x00000000010baf8a in gimple_fold_call (gsi=0x7fffffffd740, inplace=false)
at ../../src/gcc/gimple-fold.cc:5575
#6 0x00000000010be650 in fold_stmt_1 (gsi=0x7fffffffd740, inplace=false,
valueize=0x10be840 <no_follow_ssa_edges(tree_node*)>)
at ../../src/gcc/gimple-fold.cc:6327
#7 0x00000000010be8ca in fold_stmt (gsi=0x7fffffffd740) at
../../src/gcc/gimple-fold.cc:6410
#8 0x00000000010aa554 in replace_call_with_call_and_fold (gsi=0x7fffffffd740,
repl=<gimple_call 0x7fffea652f30>)
at ../../src/gcc/gimple-fold.cc:842
#9 0x00000000010b3c93 in gimple_fold_builtin_fprintf (gsi=0x7fffffffd740,
fp=<var_decl 0x7fffea652d80 fp>, fmt=<addr_expr 0x7fffea7fa4e0>,
arg=<tree 0x0>, fcode=BUILT_IN_FPRINTF) at
../../src/gcc/gimple-fold.cc:3796
#10 0x00000000010b8a66 in gimple_fold_builtin (gsi=0x7fffffffd740) at
../../src/gcc/gimple-fold.cc:5100
#11 0x00000000010baf8a in gimple_fold_call (gsi=0x7fffffffd740, inplace=false)
at ../../src/gcc/gimple-fold.cc:5575
#12 0x00000000010be650 in fold_stmt_1 (gsi=0x7fffffffd740, inplace=false,
valueize=0x10be840 <no_follow_ssa_edges(tree_node*)>)
at ../../src/gcc/gimple-fold.cc:6327
#13 0x00000000010be8ca in fold_stmt (gsi=0x7fffffffd740) at
../../src/gcc/gimple-fold.cc:6410
#14 0x0000000002c93123 in lower_stmt (gsi=0x7fffffffd740, data=0x7fffffffd950)
at ../../src/gcc/gimple-low.cc:793
#15 0x0000000002c910ee in lower_sequence (seq=0x7fffea65d1b8,
data=0x7fffffffd950) at ../../src/gcc/gimple-low.cc:229
#16 0x0000000002c935ff in lower_gimple_bind (gsi=0x7fffffffd860,
data=0x7fffffffd950) at ../../src/gcc/gimple-low.cc:882
#17 0x0000000002c92d28 in lower_stmt (gsi=0x7fffffffd860, data=0x7fffffffd950)
at ../../src/gcc/gimple-low.cc:650
#18 0x0000000002c910ee in lower_sequence (seq=0x7fffea65d178,
data=0x7fffffffd950) at ../../src/gcc/gimple-low.cc:229
#19 0x0000000002c935ff in lower_gimple_bind (gsi=0x7fffffffd930,
data=0x7fffffffd950) at ../../src/gcc/gimple-low.cc:882
#20 0x0000000002c90cf1 in lower_function_body () at
../../src/gcc/gimple-low.cc:119
#21 0x0000000002c9104f in (anonymous namespace)::pass_lower_cf::execute
(this=0x3f43e20) at ../../src/gcc/gimple-low.cc:206
#22 0x000000000140ff5a in execute_one_pass (pass=<opt_pass* 0x3f43e20
"lower"(15)>) at ../../src/gcc/passes.cc:2644
2993 gimple *repl = gimple_build_call (fn_fwrite, 4, arg0,
2994 size_one_node, len, arg1);
2995 replace_call_with_call_and_fold (gsi, repl);
