https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81662
Bug ID: 81662
Summary: fpatchable-function-entry requires nop, which nvptx
does not have
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: vries at gcc dot gnu.org
Target Milestone: ---
nop is a standard name that needs to be defined (
https://gcc.gnu.org/onlinedocs/gccint/Standard-Names.html#index-nop-instruction-pattern
):
...
‘nop’
No-op instruction. This instruction pattern name should always be defined
to output a no-op in assembler code. (const_int 0) will do as an RTL pattern.
...
And nops are used for fpatchable-function-entry:
....
void
default_print_patchable_function_entry (FILE *file,
unsigned HOST_WIDE_INT patch_area_size,
bool record_p)
{
const char *nop_templ = 0;
int code_num;
rtx_insn *my_nop = make_insn_raw (gen_nop ());
...
The nvptx target defines nop, but the output string is empty, because nvptx
does not support nops:
...
(define_insn "nop"
[(const_int 0)]
""
"")
...
So for nvptx, we run into these failures:
...
FAIL: c-c++-common/patchable_function_entry-decl.c -Wc++-compat
scan-assembler-times nop 2
FAIL: c-c++-common/patchable_function_entry-default.c -Wc++-compat
scan-assembler-times nop 3
FAIL: c-c++-common/patchable_function_entry-definition.c -Wc++-compat
scan-assembler-times nop 1
...
We should:
- skips these test-cases for nvptx
- error out for nvptx is the flag is used
- add an nvptx test-case that checks that.
