------- Comment #5 from rguenth at gcc dot gnu dot org 2006-12-31 12:57 -------
It starts as we try to fold
~(grub_scratch_mem.1_5 + 2097152) > 2147483647
from n_of_executions_at_most. The problem is we have here already
a type-mismatch:
(gdb) call debug_tree (op0)
<bit_not_expr 0xb7c20720
type <integer_type 0xb7b9a2e0 unsigned int public unsigned SI
size <integer_cst 0xb7b893f0 constant invariant 32>
unit size <integer_cst 0xb7b89180 constant invariant 4>
align 32 symtab 0 alias set -1 precision 32 min <integer_cst 0xb7b89468
0> max <integer_cst 0xb7b89450 4294967295>>
arg 0 <plus_expr 0xb7b909fc
type <integer_type 0xb7b9a284 int sizes-gimplified public SI size
<integer_cst 0xb7b893f0 32> unit size <integer_cst 0xb7b89180 4>
align 32 symtab 0 alias set -1 precision 32 min <integer_cst
0xb7b893a8 -2147483648> max <integer_cst 0xb7b893c0 2147483647>
pointer_to_this <pointer_type 0xb7b9ac38>>
arg 0 <ssa_name 0xb7c237b0 type <integer_type 0xb7b9a284 int>
visited var <var_decl 0xb7b95210 grub_scratch_mem.1> def_stmt
<gimple_modify_stmt 0xb7c27438>
version 5>
arg 1 <integer_cst 0xb7c27348 constant invariant 2097152>>>
(unsigned BIT_NOT_EXPR with signed argument.)
We get that from scev_probably_wraps_p () at
tree extreme = fold_convert (unsigned_type,
upper_bound_in_type (type, type));
delta = fold_build2 (MINUS_EXPR, unsigned_type, extreme, base);
step_abs = fold_convert (unsigned_type, step);
through fold_binary
/* Convert -1 - A to ~A. */
if (INTEGRAL_TYPE_P (type)
&& integer_all_onesp (arg0))
return fold_build1 (BIT_NOT_EXPR, type, arg1);
(that needs to read
return fold_build1 (BIT_NOT_EXPR, type, op1);
at least, which fixes this PR)
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30338
