https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94445
Bug ID: 94445
Summary: gcc.target/arm/cmse/cmse-15.c fails for cortex-m33
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: clyon at gcc dot gnu.org
Target Milestone: ---
I've noticed that when GCC is configured --target arm-none-abi
--with-mode=thumb --with-cpu=cortex-m33, the cmse-15.c test fails:
FAIL: gcc.target/arm/cmse/cmse-15.c -O2 scan-assembler-times
bl\\s+__gnu_cmse_nonsecure_call 6
FAIL: gcc.target/arm/cmse/cmse-15.c -O3 -g scan-assembler-times
bl\\s+__gnu_cmse_nonsecure_call 6
FAIL: gcc.target/arm/cmse/cmse-15.c -Os scan-assembler-times
bl\\s+__gnu_cmse_nonsecure_call 6
I've looked at the -O2 case, where 8 calls to __gnu_cmse_nonsecure_call instead
of the expected 6.
The testcase can then be reduced to:
=====================================================
typedef int __attribute__ ((cmse_nonsecure_call)) ns_foo_t (void);
typedef int s_bar_t (void);
typedef int (*s_bar_ptr) (void);
int nonsecure0 (ns_foo_t * ns_foo_p)
{
return ns_foo_p ();
}
int secure0 (s_bar_t * s_bar_p)
{
return s_bar_p ();
}
int secure2 (s_bar_ptr s_bar_p)
{
return s_bar_p ();
}
=====================================================
secure0 and secure2 make use of __gnu_cmse_nonsecure_call instead of doing a
normal call.
If I comment out nonsecure0(), then the test passes (only "bx r0" is generated
for secure0/secure2).
With nonsecure0() un-commented as above, I've looked at
arm_function_ok_for_sibcall() which is called 3 times.
The first time (for nonsecure0):
<call_expr 0x7facbe3ac630
[...]
fn <ssa_name 0x7facbe586318
type <pointer_type 0x7facbe670888 type <function_type 0x7facbe670498
ns_foo_t>
public unsigned SI size <integer_cst 0x7facbe57bfd8 32> unit-size
<integer_cst 0x7facbe58e000 4>
align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x7facbe670930>
visited var <parm_decl 0x7facbe39b180 ns_foo_p>
def_stmt GIMPLE_NOP
version:2
ptr-info 0x7facbe39c300>
The next two times (for secure0/secure2):
<call_expr 0x7facbe3acb10
[...]
fn <nop_expr 0x7facbe3b34a0
type <pointer_type 0x7facbe670888 type <function_type 0x7facbe670498
ns_foo_t>
public unsigned SI size <integer_cst 0x7facbe57bfd8 32> unit-size
<integer_cst 0x7facbe58e000 4>
align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x7facbe670930>
arg:0 <ssa_name 0x7facbe586900 type <pointer_type 0x7facbe670b28>
visited var <parm_decl 0x7facbe39b200 s_bar_p>
def_stmt GIMPLE_NOP
version:2
ptr-info 0x7facbe3b5be8>>
<call_expr 0x7facbe3ac060
[...]
fn <nop_expr 0x7facbe3ba800
type <pointer_type 0x7facbe670888 type <function_type 0x7facbe670498
ns_foo_t>
public unsigned SI size <integer_cst 0x7facbe57bfd8 32> unit-size
<integer_cst 0x7facbe58e000 4>
align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x7facbe670930>
arg:0 <ssa_name 0x7facbe586af8 type <pointer_type 0x7facbe6707e0
s_bar_ptr>
visited var <parm_decl 0x7facbe39b280 s_bar_p>
def_stmt GIMPLE_NOP
version:2
ptr-info 0x7facbe3b8b28>>
So in the last two cases, the function being called has an incorrect 'ns_foo_t'
type.
The fact that commenting out nonsecure0 makes the test pass makes me think that
some global state is modified when handling the cmse_nonsecure_call attribute,
but I couldn't find such a problem in arm_handle_cmse_nonsecure_call().
I haven't yet found where that function type is attached to the 'fn' node,
maybe that's where the problem is.
I've also noticed that in the first case 'fn' is an ssa_name, while in the two
other ones, it is a nop_expr.
I've been investigating this for quite some time, so any clue is appreciated.
