[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 Richard Biener changed: What|Removed |Added Target Milestone|7.5 |---
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 Richard Biener changed: What|Removed |Added Target Milestone|7.4 |7.5
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 Richard Biener changed: What|Removed |Added Target Milestone|7.3 |7.4 --- Comment #18 from Richard Biener --- GCC 7.3 is being released, adjusting target milestone.
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 Richard Biener changed: What|Removed |Added Target Milestone|7.2 |7.3
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 Andrew Pinski changed: What|Removed |Added Target Milestone|7.3 |---
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 Richard Biener changed: What|Removed |Added Target Milestone|7.2 7.2 |7.3 7.3 --- Comment #18 from Richard Biener --- GCC 7.2 is being released, adjusting target milestone. --- Comment #19 from Richard Biener --- GCC 7.2 is being released, adjusting target milestone.
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 Richard Biener changed: What|Removed |Added Target Milestone|7.2 7.2 |7.3 7.3 --- Comment #18 from Richard Biener --- GCC 7.2 is being released, adjusting target milestone. --- Comment #19 from Richard Biener --- GCC 7.2 is being released, adjusting target milestone.
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 Jakub Jelinek changed: What|Removed |Added Target Milestone|7.0 |7.2 --- Comment #17 from Jakub Jelinek --- GCC 7.1 has been released.
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 --- Comment #16 from H.J. Lu --- (In reply to Martin Liška from comment #15) > > > > Not with interrupt handler which needs different epilogue and prologue. > > I see, however I'm not sure it's known information when IPA ICF is running. > Or am I wrong? The information is available. But I don't know if ICF should be concerned. We can disable ICF for interrupt handler or use it as a feature to detect code duplication for interrupt handler, which I submitted a patch for: https://gcc.gnu.org/ml/gcc-patches/2016-10/msg02177.html
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 --- Comment #15 from Martin Liška --- > > Not with interrupt handler which needs different epilogue and prologue. I see, however I'm not sure it's known information when IPA ICF is running. Or am I wrong?
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098
--- Comment #14 from H.J. Lu ---
(In reply to Martin Liška from comment #13)
> (In reply to H.J. Lu from comment #12)
> > (In reply to Martin Liška from comment #10)
> > > (In reply to H.J. Lu from comment #9)
> > > > (In reply to Richard Biener from comment #6)
> > > > > Why would we be not able to tailcall in an interupt handler?
> > > >
> > > > We need to verify that the only instruction in an interrupt handler
> > > > is a tail call to another interrupt handler. On the other hand,
> > > > this interrupt handler isn't really needed at all.
> > >
> > > That can be vefief by fact that the symbol should have only one call (tail
> > > call) and set node->icf_merged == true.
> >
> > Another issue with ICF tail call:
> >
> > ;; Function foo1 (foo1, funcdef_no=3, decl_uid=1443, cgraph_uid=0,
> > symbol_order=0)
> >
> > foo1 (void * p)
> > {
> > ;; basic block 2, loop depth 0
> > ;;pred: ENTRY
> > foo2 (p_2(D)); [tail call]
> > ^^^ This isn't the same as sibcall.
> > return;
> > ^^ Here is a return statement.
> > ;;succ: EXIT
> >
> > }
>
> If I remember correctly, this is gimple representation of the tail-call. If
> you look at the generated binary, you'll see really just the jump
> instruction:
>
> foo2:
> .LFB1:
> .cfi_startproc
> movl$4276093056, %eax
> movl$0, (%rax)
> ret
> .cfi_endproc
> .LFE1:
> .size foo2, .-foo2
> .p2align 4,,15
> .globl foo1
> .type foo1, @function
> foo1:
> .LFB3:
> .cfi_startproc
> jmp foo2
> .cfi_endproc
Not with interrupt handler which needs different epilogue and prologue.
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098
--- Comment #13 from Martin Liška ---
(In reply to H.J. Lu from comment #12)
> (In reply to Martin Liška from comment #10)
> > (In reply to H.J. Lu from comment #9)
> > > (In reply to Richard Biener from comment #6)
> > > > Why would we be not able to tailcall in an interupt handler?
> > >
> > > We need to verify that the only instruction in an interrupt handler
> > > is a tail call to another interrupt handler. On the other hand,
> > > this interrupt handler isn't really needed at all.
> >
> > That can be vefief by fact that the symbol should have only one call (tail
> > call) and set node->icf_merged == true.
>
> Another issue with ICF tail call:
>
> ;; Function foo1 (foo1, funcdef_no=3, decl_uid=1443, cgraph_uid=0,
> symbol_order=0)
>
> foo1 (void * p)
> {
> ;; basic block 2, loop depth 0
> ;;pred: ENTRY
> foo2 (p_2(D)); [tail call]
> ^^^ This isn't the same as sibcall.
> return;
> ^^ Here is a return statement.
> ;;succ: EXIT
>
> }
If I remember correctly, this is gimple representation of the tail-call. If you
look at the generated binary, you'll see really just the jump instruction:
foo2:
.LFB1:
.cfi_startproc
movl$4276093056, %eax
movl$0, (%rax)
ret
.cfi_endproc
.LFE1:
.size foo2, .-foo2
.p2align 4,,15
.globl foo1
.type foo1, @function
foo1:
.LFB3:
.cfi_startproc
jmp foo2
.cfi_endproc
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098
--- Comment #12 from H.J. Lu ---
(In reply to Martin Liška from comment #10)
> (In reply to H.J. Lu from comment #9)
> > (In reply to Richard Biener from comment #6)
> > > Why would we be not able to tailcall in an interupt handler?
> >
> > We need to verify that the only instruction in an interrupt handler
> > is a tail call to another interrupt handler. On the other hand,
> > this interrupt handler isn't really needed at all.
>
> That can be vefief by fact that the symbol should have only one call (tail
> call) and set node->icf_merged == true.
Another issue with ICF tail call:
;; Function foo1 (foo1, funcdef_no=3, decl_uid=1443, cgraph_uid=0,
symbol_order=0)
foo1 (void * p)
{
;; basic block 2, loop depth 0
;;pred: ENTRY
foo2 (p_2(D)); [tail call]
^^^ This isn't the same as sibcall.
return;
^^ Here is a return statement.
;;succ: EXIT
}
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098
--- Comment #11 from H.J. Lu ---
(In reply to Martin Liška from comment #10)
> (In reply to H.J. Lu from comment #9)
> > (In reply to Richard Biener from comment #6)
> > > Why would we be not able to tailcall in an interupt handler?
> >
> > We need to verify that the only instruction in an interrupt handler
> > is a tail call to another interrupt handler. On the other hand,
> > this interrupt handler isn't really needed at all.
>
> That can be vefief by fact that the symbol should have only one call (tail
> call) and set node->icf_merged == true.
My current change:
@ -28014,7 +28026,19 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
if (fndecl
&& (lookup_attribute ("interrupt",
TYPE_ATTRIBUTES (TREE_TYPE (fndecl)
- error ("interrupt service routine can't be called directly");
+ {
+if (lookup_attribute ("interrupt",
+ TYPE_ATTRIBUTES (TREE_TYPE (cfun->decl
+ {
+error ("interrupt service routine %q+D can't be called directly",
+ fndecl);
+inform (input_location,
+ "is interrupt service routine %q+D equivalent to %q+D?",
+ fndecl, cfun->decl);
+ }
+else
+ error ("interrupt service routine can't be called directly");
+ }
}
else
fndecl = NULL_TREE;
gives
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -Os -m32 -mno-sse -mno-mmx
-mno-80387 -S -o foo1.s foo1.i
foo1.i: In function ‘foo1’:
foo1.i:10:33: error: interrupt service routine ‘foo2’ can't be called directly
__attribute__((interrupt)) void foo2 (void *p)
^~~~
foo1.i:4:6: note: is interrupt service routine ‘foo2’ equivalent to ‘foo1’?
void foo1 (void *p)
^~~~
Makefile:34: recipe for target 'foo1.s' failed
make: *** [foo1.s] Error 1
[hjl@gnu-6 pr78098]$
Since foo1 == foo2, there is no reason for foo2 at all. It reduces
the code size, which is very important in embedded environment.
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 --- Comment #10 from Martin Liška --- (In reply to H.J. Lu from comment #9) > (In reply to Richard Biener from comment #6) > > Why would we be not able to tailcall in an interupt handler? > > We need to verify that the only instruction in an interrupt handler > is a tail call to another interrupt handler. On the other hand, > this interrupt handler isn't really needed at all. That can be vefief by fact that the symbol should have only one call (tail call) and set node->icf_merged == true.
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 --- Comment #9 from H.J. Lu --- (In reply to Richard Biener from comment #6) > Why would we be not able to tailcall in an interupt handler? We need to verify that the only instruction in an interrupt handler is a tail call to another interrupt handler. On the other hand, this interrupt handler isn't really needed at all.
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098
--- Comment #8 from H.J. Lu ---
(In reply to Martin Liška from comment #7)
> > Can ICF turn foo1 into a tail call to foo2 when foo2 has an interrupt
> > attribute?
>
> Problem here is that comp_type_attributes returns 1 as
>
> $18 = {name = 0x19d357b "interrupt", min_length = 0, max_length = 0,
> decl_required = false, type_required = true, function_type_required = true,
> handler = 0x1195b30 bool*)>, affects_type_identity = false}
>
> has set affects_type_identity == false. I would expect to have the flag set
> to true? Is it bug?
I have a patch for them.
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098
--- Comment #7 from Martin Liška ---
> Can ICF turn foo1 into a tail call to foo2 when foo2 has an interrupt
> attribute?
Problem here is that comp_type_attributes returns 1 as
$18 = {name = 0x19d357b "interrupt", min_length = 0, max_length = 0,
decl_required = false, type_required = true, function_type_required = true,
handler = 0x1195b30 , affects_type_identity = false}
has set affects_type_identity == false. I would expect to have the flag set to
true? Is it bug?
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 --- Comment #6 from Richard Biener --- Why would we be not able to tailcall in an interupt handler?
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 --- Comment #5 from H.J. Lu --- (In reply to Martin Liška from comment #4) > Hello H.J. > As interrupt handler attribute is very specific and rare attribute, I'm > suggesting to basically skip all functions in IPA ICF analysis that have > such attribute. > > Does it work for you? I'd like to keep it as a "feature" to detect code duplication in interrupt handler, like [hjl@gnu-6 pr78098]$ /export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc -B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -Os -m32 -mno-sse -mno-mmx -mno-80387 -S -o foo1.s foo1.i foo1.i: In function ‘foo1’: foo1.i:10:33: error: interrupt service routine ‘foo2’ can't be called directly __attribute__((interrupt)) void foo2 (void *p) ^~~~ foo1.i:10:33: note: is interrupt service routine ‘foo1’ identical to ‘foo2’? [hjl@gnu-6 pr78098]$
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 Martin Liška changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2016-10-24 Target Milestone|--- |7.0 Ever confirmed|0 |1 --- Comment #4 from Martin Liška --- Hello H.J. As interrupt handler attribute is very specific and rare attribute, I'm suggesting to basically skip all functions in IPA ICF analysis that have such attribute. Does it work for you?
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098
--- Comment #3 from H.J. Lu ---
Another problem:
[hjl@gnu-6 pr78098]$ cat foo2.i
void bar (int);
void foo1 (void *p)
{
bar (0);
*((int *)0xFEE00080) = 0;
}
__attribute__((interrupt)) void foo2 (void *p)
{
bar (0);
*((int *)0xFEE00080) = 0;
}
[hjl@gnu-6 pr78098]$ make foo2.s
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -Os -DQM_LAKEMONT -m32 -miamcu
-mno-sse -mno-mmx -mno-80387 -S -o foo2.s foo2.i
foo2.i: In function ‘foo1’:
foo2.i:3:6: error: interrupt service routine can't be called directly
void foo1 (void *p)
^~~~
Makefile:33: recipe for target 'foo2.s' failed
make: *** [foo2.s] Error 1
[hjl@gnu-6 pr78098]$
Can ICF turn foo1 into a tail call to foo2 when foo2 has an interrupt
attribute?
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098
--- Comment #2 from H.J. Lu ---
GCC correctly identified that foo1 == foo2 and generate a tail call.
But we don't want tail call in interrupt handler. On the other hand,
there is no need to have 2 identical copies of an interrupt handler.
There should be only one interrupt handler or they should be different.
This patch
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index eef6d7b..be40ad9 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -28014,7 +28014,8 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
if (fndecl
&& (lookup_attribute ("interrupt",
TYPE_ATTRIBUTES (TREE_TYPE (fndecl)
- error ("interrupt service routine can't be called directly");
+ error ("interrupt service routine %q+D can't be called directly",
+ fndecl);
}
else
fndecl = NULL_TREE;
changes the error message to
foo.i: In function ‘foo1’:
foo.i:9:33: error: interrupt service routine ‘foo2’ can't be called directly
__attribute__((interrupt)) void foo2 (void *p)
to indicate that foo2 is called from foo1.
[Bug middle-end/78098] error: interrupt service routine can't be called directly
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78098 H.J. Lu changed: What|Removed |Added CC||marxin at gcc dot gnu.org Component|target |middle-end --- Comment #1 from H.J. Lu --- It is generated by IPA-ICF.
