Re: An abridged "Writing C" for the gcc web pages

[Paul_Koning]

> On Apr 22, 2016, at 12:21 PM, Bernd Schmidt  wrote:
> 
> (Apologies if you get this twice, the mailing list didn't like the html 
> attachment in the first attempt).
> 
> We frequently get malformatted patches, and it's been brought to my attention 
> that some people don't even make the effort to read the GNU coding standards 
> before trying to contribute code. TL;DR seems to be the excuse, and while I 
> find that attitude inappropriate, we could probably improve the situation by 
> spelling out the most basic rules in an abridged document on our webpages. 
> Below is a draft I came up with. Thoughts?

Would you expect people to conform to the abridged version or the full 
standard?  If the full standard, then publishing an abridged version is not a 
good idea, it will just cause confusion.  Let the full standard be the rule, 
make people read it, and if they didn't bother that's their problem.

paul

RE: PING^3: [PATCH]: New configure options that make the compiler use -fPIE and -pie as default option

[Paul_Koning]

From: gcc-patches-ow...@gcc.gnu.org [gcc-patches-ow...@gcc.gnu.org] on behalf 
of H.J. Lu [hjl.to...@gmail.com]
Sent: Tuesday, May 19, 2015 11:27 AM
To: Joseph Myers
Cc: Magnus Granberg; GCC Patches
Subject: Re: PING^3: [PATCH]: New configure options that make the compiler use 
-fPIE and -pie as default option

On Tue, May 19, 2015 at 8:21 AM, Joseph Myers jos...@codesourcery.com wrote:
 ...
 I think the whole thing should be posted as one patch, with both the
 target-independent changes and the target-specific changes for all
 targets.


That is what makes me concerned.  I have some simple target-specified
patches which weren't reviewed for years. What will happen if no one
reviews some simple target-specified changes due to

1. Reviewers don't have access to those targets.
2. Target maintainers aren't review them.
3. There are no clear maintainers for those targets.

As the result, my patch may go nowhere.
---

But that hasn't stopped others from posting patches like that, or getting them 
approved.  And we also have global maintainers who can approve things.  It 
feels a bit like a hypothetical issue is being used as a reason to do part of 
the job.


paul

Re: Remove LIBGCC2_HAS_?F_MODE target macros

[Paul_Koning]

On Sep 11, 2014, at 9:22 PM, Joseph S. Myers jos...@codesourcery.com wrote:

 This patch removes the LIBGCC2_HAS_{SF,DF,XF,TF}_MODE target macros,
 replacing them by predefines with -fbuilding-libgcc, together with a
 target hook that can influence those predefines when needed.
 
 The new default is that a floating-point mode is supported in libgcc
 if (a) it passes the scalar_mode_supported_p hook (otherwise it's not
 plausible for it to be supported in libgcc) and (b) it's one of those
 four modes (since those are the modes for which libgcc hardcodes the
 possibility of support).  The target hook can override the default
 choice (in either direction) for modes that pass
 scalar_mode_supported_p (although overriding in the direction of
 returning true when the default would return false only makes sense if
 all relevant functions are specially defined in libgcc for that
 particular target).
 
 The previous default settings depended on various settings such as
 LIBGCC2_LONG_DOUBLE_TYPE_SIZE, as well as targets defining the above
 target macros if the default wasn't correct.
 
 The default scalar_mode_supported_p only declares a floating-point
 mode to be supported if it matches one of float / double / long
 double.  This means that in most cases where a mode is only supported
 conditionally in libgcc (TFmode only supported if it's the mode of
 long double, most commonly), the default gets things right.  Overrides
 were needed in the following cases:
 
 * SFmode would always have been supported in libgcc (the condition was
  BITS_PER_UNIT == 8, true for all current targets), but pdp11
  defaults to 64-bit float, and in that case SFmode would fail
  scalar_mode_supported_p.  I don't know if libgcc actually built for
  pdp11 (and the port may well no longer be being used), but this
  patch adds a scalar_mode_supported_p hook to it to ensure SFmode is
  treated as supported.

I thought it does build.  I continue to work to keep that port alive.

The change looks fine.

The ideal solution, I think, would be to handle the choice of float length that 
the pdp11 target has via the multilib machinery.  Currently it does not do 
that.  If multilib were added for that at some point, would that require a 
change of the code in that hook?

paul

Re: [PATCH 8/8] Add a common .md file and define standard constraints there

[Paul_Koning]

On Jun 12, 2014, at 3:24 PM, Segher Boessenkool seg...@kernel.crashing.org 
wrote:

 On Thu, Jun 05, 2014 at 10:43:25PM +0100, Richard Sandiford wrote:
 This final patch uses a common .md file to define all standard
 constraints except 'g'.
 
 I had a look at what targets still use g.  Note: there can be
 errors in this, it's all based on  \g[,]  :-)
 
 * frv and mcore use g in commented-out patterns;
 * cr16, mcore, picochip, rl78, and sh use g where they mean rm
  or m;
 * m68k uses it (in a dbne pattern) where the C template splits
  the r, m, i cases again;
 * bfin, fr30, h8300, m68k, rs6000, and v850 use it as the second
  operand (# bytes pushed) of the call patterns; that operand is
  unused in all these cases, could just be ;
 * cris, m68k, pdp11, and vax actually use g.
 
 So it won't be all that much work to completely get rid of g.
 Do we want that?

Is it simply a matter of replacing “g” by “mri”?  That’s what the doc suggests. 
 Or is there more to the story than that?

paul

Re: [Patch, RTL] Eliminate redundant vec_select moves.

[Paul_Koning]

On Dec 10, 2013, at 9:50 AM, Kirill Yukhin kirill.yuk...@gmail.com wrote:

 Hello,
 On 09 Dec 14:08, H.J. Lu wrote:
 There are no regressions on Linux/x86-64 with -m32 and -m64.
 Can you check if it improves code quality on x886?
 
 That is exactly what I was talking about. However I wasn't sure
 that we can change already defined (and used throughout ports)
 target hook.
 
 ...
 
 Attached patch + updated test.

You're missing the documentation change needed for this.

paul

Re: [Patch, RTL] Eliminate redundant vec_select moves.

[Paul_Koning]

On Dec 10, 2013, at 2:12 PM, H.J. Lu hjl.to...@gmail.com wrote:

 On Tue, Dec 10, 2013 at 11:05 AM, Tejas Belagod tbela...@arm.com wrote:
 ...
 So, if (subreg:DI (match_operand:V4SF 1 register_operand x,x) 0) is a
 valid subreg, why not allow it in CANNOT_CHANGE_MODE_CLASS (like in Kirill's
 patch http://gcc.gnu.org/ml/gcc-patches/2013-12/msg00987.html) and resolve
 the actual register later in subreg_get_info ()?
 
 Let's wait for Kirill's results on GCC testsuite.

I'm puzzled.  What is the connection between testsuite results and a design 
decision about a code change?  The question remains valid even if the testsuite 
didn't exist at all.

paul

Re: Turn most genrecog warnings into errors

[Paul_Koning]

On Nov 22, 2013, at 3:43 AM, Richard Sandiford rdsandif...@googlemail.com 
wrote:

 genrecog does some useful sanity checks on the .md files.  At the moment
 it only reports most of the problems as warnings though, which means you
 won't notice them unless you specifically look.
 
 I think the only message in validate_pattern that deserves to be a
 warning is the one about missing modes, since the current code does
 warn about valid cases.  It would be good to tighten that up at some
 point, but not today.
 
 Tested by building cc1 with and without the warning for each backend
 (picking an arbitrary configuration triple in each case).  The patch
 below updates backends for which the fix was truly obvious:
 removing constraints from things that don't allow constraints,
 replacing one target-independent predicate with another that
 doesn't accept immediates, or using match_operand rather than
 match_test to test subpredicates.  I've posted separate patches
 for the backends that need changing in other ways.
 
 Also tested in the normal way on x86_64-linux-gnu.  OK to install?
 
 Thanks,
 Richard
 
 
 gcc/
   * genrecog.c (validate_pattern): Treat all messages except missing
   modes as errors.
   * config/epiphany/epiphany.md: Remove constraints from
   define_peephole2s.
   * config/h8300/h8300.md: Remove constraints from define_splits.
   * config/msp430/msp430.md: Likewise.
   * config/mcore/mcore.md (movdi_i, movsf_i, movdf_k): Use
   nonimmediate_operand rather than general_operand for operand 0.
   * config/moxie/moxie.md (*movsi, *movqi, *movhi): Likewise.
   * config/pdp11/predicates.md (float_operand, float_nonimm_operand):
   Use match_operator rather than match_test to invoke general_operand.
   * config/v850/v850.md (*movqi_internal, *movhi_internal)
   (*movsi_internal_v850e, *movsi_internal, *movsf_internal): Likewise.

I think you meant use match_operand rather than ... (in 
config/pdp11/predicates.md).

paul

Re: PING^2: [patch] pr/54508: fix incomplete debug information for class

[Paul_Koning]

On Oct 5, 2012, at 6:05 PM, Cary Coutant wrote:

 There certainly is a fair amount of code in dwarf2read.c in gdb to handle 
 DW_AT_declaration and do things differently for declarations.
 
 Should I rework this patch to use that mechanism instead?  If so, how?  If 
 the class is marked only by prune_unused_types_mark visiting it as a parent, 
 but hasn't been marked by ??? that visits all its children, then emit it 
 with a DW_AT_declaration marking?
 
 One question I'd consider is what do you want to see in the debugger
 if this truly is the only debug info you have for the class? (For
 example, in the test case you added, a DW_AT_declaration attribute
 won't help if there's no full definition of the class anywhere else.)
 Is it reasonable to just show a truncated class definition in that
 case, or do you want the full definition available. My tentative
 answer would be that we do the pruning here because we expect there to
 be a full definition somewhere else, and that the lack of a
 DW_AT_declaration attribute is the bug.

The answer appears to be:
1. Until the full symbols have been read (via gdb -r, or by reference to 
another symbol in that compilation unit) such declarations are not visible.  
Once the full symbols have been read, a class marked as DW_AT_declaration is 
shown as imcomplete type which makes sense.

I think this is reasonable behavior.  I confirmed that if you do have a 
definition elsewhere, gdb does the correct thing.  That's what you would 
expect, given that the DW_AT_declaration flag was already being generated (for 
imcomplete types).
 
 As you've discovered, however, it's not straightforward. You'll want
 to add the declaration attribute if you mark the DIE from below, but
 not from any reference where dokids is true. Alternatively, add the
 declaration attribute if any of its children are pruned. Perhaps that
 could be done in prune_unused_types_prune().
 
 If you're willing to rework the patch this way (assuming GDB does the
 right thing with it), I think that would be better. Thanks.
 
 -cary

Attached is the revised patch.  It marks classes as declaration if they 
weren't marked by one of the mark functions that visits children, and something 
was actually pruned.  That second check is needed, otherwise the class 
Executor in testcase nested-3.C gets marked as a declaration.

The testcase has been reworked to check both aspects.  Struct s gets defined 
(because a variable of that type is defined), while class c and union u are 
not, so they are marked as declaration while struct s is not marked.  The 
testcase verifies that.

Tested by build and check RUNTESTFLAGS=dwarf2.exp on Linux and Darwin.  Ok to 
commit?

paul

ChangeLog:

2012-10-23  Paul Koning  n...@arrl.net

* dwarf2out.c (prune_unused_types_prune): If pruning a class and
not all its children were marked, add DW_AT_declaration flag.

testcases/ChangeLog:

2012-10-23  Paul Koning  n...@arrl.net

* g++.dg/debug/dwarf2/pr54508.C: New.

Index: gcc/dwarf2out.c
===
--- gcc/dwarf2out.c (revision 192405)
+++ gcc/dwarf2out.c (working copy)
@@ -21218,6 +21218,7 @@
 prune_unused_types_prune (dw_die_ref die)
 {
   dw_die_ref c;
+  int pruned = 0;
 
   gcc_assert (die-die_mark);
   prune_unused_types_update_strings (die);
@@ -21240,13 +21241,24 @@
  prev-die_sib = c-die_sib;
  die-die_child = prev;
}
- return;
+ pruned = 1;
+ goto finished;
}
 
 if (c != prev-die_sib)
-  prev-die_sib = c;
+  {
+   prev-die_sib = c;
+   pruned = 1;
+  }
 prune_unused_types_prune (c);
   } while (c != die-die_child);
+
+ finished:
+  /* If we pruned children, and this is a class, mark it as a 
+ declaration to inform debuggers that this is not a complete
+ class definition.  */
+  if (pruned  die-die_mark == 1  class_scope_p (die))
+add_AT_flag (die, DW_AT_declaration, 1);
 }
 
 /* Remove dies representing declarations that we never use.  */

Index: gcc/testsuite/g++.dg/debug/dwarf2/pr54508.C
===
--- gcc/testsuite/g++.dg/debug/dwarf2/pr54508.C (revision 0)
+++ gcc/testsuite/g++.dg/debug/dwarf2/pr54508.C (revision 0)
@@ -0,0 +1,72 @@
+// PR debug/54508
+// { dg-do compile }
+// { dg-options -g2 -dA -fno-merge-debug-strings }
+
+// { dg-final { scan-assembler-not \cbase0\\[ \t\]+\[#;/!|@\]+ 
DW_AT_name } }
+// { dg-final { scan-assembler \c0\\[ \t\]+\[#;/!|@\]+ 
DW_AT_name\[\r\n\]+\[\^\r\n\]+\[\r\n\]+\[\^\r\n\]+\[\r\n\]+\[\^#;/!|@\]+\[#;/!|@\]+
 DW_AT_decl_line\[\r\n\]+\[\^#;/!|@\]+\[#;/!|@\]+ DW_AT_declaration } }
+// { dg-final { scan-assembler-not \OPCODE0\\[ \t\]+\[#;/!|@\]+ 
DW_AT_name } }
+// { dg-final { scan-assembler-not \bi0\\[ \t\]+\[#;/!|@\]+ DW_AT_name 
} }
+// { dg-final { scan-assembler-not \si0\\[ \t\]+\[#;/!|@\]+ DW_AT_name 
} }
+// { 

Re: PING^2: [patch] pr/54508: fix incomplete debug information for class

[Paul_Koning]

On Oct 23, 2012, at 2:02 PM, Jason Merrill wrote:

 OK.
 
 Jason

Thanks.  Committed.

paul

Re: PING^2: [patch] pr/54508: fix incomplete debug information for class

[Paul_Koning]

On Oct 5, 2012, at 4:16 AM, Jakub Jelinek wrote:

 On Thu, Oct 04, 2012 at 05:26:11PM -0700, Cary Coutant wrote:
 Index: gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C
 ===
 --- gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C (revision 192048)
 +++ gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C (working copy)
 @@ -59,11 +59,11 @@
 // { dg-final { scan-assembler foo\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler staticfn1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler staticfn2\[^\n\r\]*DW_AT_name } }
 -// { dg-final { scan-assembler-not staticfn3\[^\n\r\]*DW_AT_name } }
 -// { dg-final { scan-assembler-not staticfn4\[^\n\r\]*DW_AT_name } }
 +// { dg-final { scan-assembler staticfn3\[^\n\r\]*DW_AT_name } }
 +// { dg-final { scan-assembler staticfn4\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler-not staticfn5\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler-not staticfn6\[^\n\r\]*DW_AT_name } }
 -// { dg-final { scan-assembler-not method1\[^\n\r\]*DW_AT_name } }
 +// { dg-final { scan-assembler method1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg2\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg3\[^\n\r\]*DW_AT_name } }
 
 The fact that these two tests were specifically checking for the
 absence of staticfn3 and staticfn4 leads me to believe that the
 current behavior is deliberate. Jakub, that change was yours (it dates
 back to November 2008). Are you OK with Paul's change?
 
 Yes, thought it would be interesting to get some .debug_info size growth
 numbers for a few projects (say libstdc++.so and some larger C++ codebase
 (some KDE core library, or OO.o) without/with the patch, to see how much
 does it bring with it (I'm not that much worried about the DW_TAG_subprogram
 added itself, but about about types it will additionally bring in).
 We have dwz and likely would get most of the growth back due to redundancy
 removal though.
 
   Jakub

I did a quick test on a large application of ours where this issue was causing 
trouble.  Without the patch, it generates 115 MB of debug data; with the patch, 
that grows to 120 MB.

paul

Re: PING^2: [patch] pr/54508: fix incomplete debug information for class

[Paul_Koning]

On Oct 5, 2012, at 11:34 AM, paul_kon...@dell.com
 paul_kon...@dell.com wrote:

 
 On Oct 5, 2012, at 4:16 AM, Jakub Jelinek wrote:
 
 On Thu, Oct 04, 2012 at 05:26:11PM -0700, Cary Coutant wrote:
 Index: gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C
 ===
 --- gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C (revision 192048)
 +++ gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C (working copy)
 @@ -59,11 +59,11 @@
 // { dg-final { scan-assembler foo\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler staticfn1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler staticfn2\[^\n\r\]*DW_AT_name } }
 -// { dg-final { scan-assembler-not staticfn3\[^\n\r\]*DW_AT_name } }
 -// { dg-final { scan-assembler-not staticfn4\[^\n\r\]*DW_AT_name } }
 +// { dg-final { scan-assembler staticfn3\[^\n\r\]*DW_AT_name } }
 +// { dg-final { scan-assembler staticfn4\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler-not staticfn5\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler-not staticfn6\[^\n\r\]*DW_AT_name } }
 -// { dg-final { scan-assembler-not method1\[^\n\r\]*DW_AT_name } }
 +// { dg-final { scan-assembler method1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg2\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg3\[^\n\r\]*DW_AT_name } }
 
 The fact that these two tests were specifically checking for the
 absence of staticfn3 and staticfn4 leads me to believe that the
 current behavior is deliberate. Jakub, that change was yours (it dates
 back to November 2008). Are you OK with Paul's change?
 
 Yes, thought it would be interesting to get some .debug_info size growth
 numbers for a few projects (say libstdc++.so and some larger C++ codebase
 (some KDE core library, or OO.o) without/with the patch, to see how much
 does it bring with it (I'm not that much worried about the DW_TAG_subprogram
 added itself, but about about types it will additionally bring in).
 We have dwz and likely would get most of the growth back due to redundancy
 removal though.
 
  Jakub
 
 I did a quick test on a large application of ours where this issue was 
 causing trouble.  Without the patch, it generates 115 MB of debug data; with 
 the patch, that grows to 120 MB.

So given the comments, is this patch now ok to commit?

Thanks,
paul

Re: PING^2: [patch] pr/54508: fix incomplete debug information for class

[Paul_Koning]

On Oct 5, 2012, at 2:43 PM, Cary Coutant wrote:

 It seems to me that there are cases where we just want to emit the
 class for the context info (like a namespace, which doesn't have to be
 complete everywhere). Is there a way to tell the debugger that this
 class declaration is incomplete and that it should look elsewhere for
 a full definition?
 
 I think DW_AT_declaration would be appropriate.
 
 Yeah, that's what I was thinking. I was going to check with dje to see
 if GDB would do the right thing in that case.
 
 -cary

Does that mean I should hold off committing this change?

paul

Re: PING^2: [patch] pr/54508: fix incomplete debug information for class

[Paul_Koning]

On Oct 5, 2012, at 2:43 PM, Cary Coutant wrote:

 It seems to me that there are cases where we just want to emit the
 class for the context info (like a namespace, which doesn't have to be
 complete everywhere). Is there a way to tell the debugger that this
 class declaration is incomplete and that it should look elsewhere for
 a full definition?
 
 I think DW_AT_declaration would be appropriate.
 
 Yeah, that's what I was thinking. I was going to check with dje to see
 if GDB would do the right thing in that case.
 
 -cary

There certainly is a fair amount of code in dwarf2read.c in gdb to handle 
DW_AT_declaration and do things differently for declarations.

Should I rework this patch to use that mechanism instead?  If so, how?  If the 
class is marked only by prune_unused_types_mark visiting it as a parent, but 
hasn't been marked by ??? that visits all its children, then emit it with a 
DW_AT_declaration marking?

paul

Re: PING^2: [patch] pr/54508: fix incomplete debug information for class

[Paul_Koning]

On Oct 5, 2012, at 6:05 PM, Cary Coutant wrote:

 There certainly is a fair amount of code in dwarf2read.c in gdb to handle 
 DW_AT_declaration and do things differently for declarations.
 
 Should I rework this patch to use that mechanism instead?  If so, how?  If 
 the class is marked only by prune_unused_types_mark visiting it as a parent, 
 but hasn't been marked by ??? that visits all its children, then emit it 
 with a DW_AT_declaration marking?
 
 One question I'd consider is what do you want to see in the debugger
 if this truly is the only debug info you have for the class? (For
 example, in the test case you added, a DW_AT_declaration attribute
 won't help if there's no full definition of the class anywhere else.)
 Is it reasonable to just show a truncated class definition in that
 case, or do you want the full definition available. My tentative
 answer would be that we do the pruning here because we expect there to
 be a full definition somewhere else, and that the lack of a
 DW_AT_declaration attribute is the bug.
 
 As you've discovered, however, it's not straightforward. You'll want
 to add the declaration attribute if you mark the DIE from below, but
 not from any reference where dokids is true. Alternatively, add the
 declaration attribute if any of its children are pruned. Perhaps that
 could be done in prune_unused_types_prune().
 
 If you're willing to rework the patch this way (assuming GDB does the
 right thing with it), I think that would be better. Thanks.
 
 -cary

I'll give it a try.  I'll keep the existing patch in reserve in case we run out 
of time before Phase 1 end -- it would be good to have some sort of fix for 
this bug even if it's not the ideal one.

paul

Re: PING^2: [patch] pr/54508: fix incomplete debug information for class

[Paul_Koning]

On Oct 4, 2012, at 1:38 PM, Cary Coutant wrote:

  /* We also have to mark its parents as used.
 -(But we don't want to mark our parents' kids due to this.)  */
 +(But we don't want to mark our parent's kids due to this,
 +unless it is a class.)  */
  if (die-die_parent)
 -   prune_unused_types_mark (die-die_parent, 0);
 +   prune_unused_types_mark (die-die_parent,
 +(die-die_parent-die_tag == 
 DW_TAG_class_type ||
 + die-die_parent-die_tag == 
 DW_TAG_structure_type ||
 + die-die_parent-die_tag == 
 DW_TAG_union_type));
 
 I'd suggest replacing these conditions with a call to class_scope_p().
 That will also cover DW_TAG_interface_type, which might be irrelevant
 for this particular case, but is probably good to cover in the general
 case.
 
 -cary

Thanks, that makes it very simple.  Here is the updated patch.

Ok to commit with this change?

paul

ChangeLog:

2012-10-04  Paul Koning  n...@arrl.net

* dwarf2out.c (prune_unused_types_mark): Mark all of parent's
children if parent is a class.

testsuite/ChangeLog:

2012-10-04  Paul Koning  n...@arrl.net

* g++.dg/debug/dwarf2/pr54508.C: New.

Index: gcc/dwarf2out.c
===
--- gcc/dwarf2out.c (revision 192048)
+++ gcc/dwarf2out.c (working copy)
@@ -21035,9 +21035,11 @@
   prune_unused_types_mark_generic_parms_dies (die);
 
   /* We also have to mark its parents as used.
-(But we don't want to mark our parents' kids due to this.)  */
+(But we don't want to mark our parent's kids due to this,
+unless it is a class.)  */
   if (die-die_parent)
-   prune_unused_types_mark (die-die_parent, 0);
+   prune_unused_types_mark (die-die_parent, 
+class_scope_p (die-die_parent));
 
   /* Mark any referenced nodes.  */
   prune_unused_types_walk_attribs (die);
Index: testsuite/g++.dg/debug/dwarf2/pr54508.C
===
--- testsuite/g++.dg/debug/dwarf2/pr54508.C (revision 0)
+++ testsuite/g++.dg/debug/dwarf2/pr54508.C (revision 0)
@@ -0,0 +1,67 @@
+// PR debug/54508
+// { dg-do compile }
+// { dg-options -g2 -dA }
+
+// { dg-final { scan-assembler \cbase0\\[ \t\]+\[#;/!|@\]+ 
DW_AT_name\|DW_AT_name: \cbase\ } }
+// { dg-final { scan-assembler \OPCODE0\\[ \t\]+\[#;/!|@\]+ 
DW_AT_name\|DW_AT_name: \OPCODE\ } }
+// { dg-final { scan-assembler \bi0\\[ \t\]+\[#;/!|@\]+ DW_AT_name } }
+// { dg-final { scan-assembler \si0\\[ \t\]+\[#;/!|@\]+ DW_AT_name } }
+// { dg-final { scan-assembler \f10\\[ \t\]+\[#;/!|@\]+ DW_AT_name } }
+// { dg-final { scan-assembler \f20\\[ \t\]+\[#;/!|@\]+ DW_AT_name } }
+// { dg-final { scan-assembler-not \nc0\\[ \t\]+\# 
DW_AT_name\|DW_AT_name: \nc\ } }
+
+class cbase
+
+{
+public:
+ static int si;
+int bi;
+};
+
+class c : public cbase
+
+{
+public:
+ enum
+ {
+  OPCODE = 251
+ };
+ int i ;
+ static const char *testc (void) { return foo; }
+};
+
+struct s
+{
+int f1;
+static const char *tests (void) { return test; }
+};
+
+union u
+{
+int f2;
+double d;
+static const char *testu (void) { return test union; }
+};
+
+namespace n 
+{
+const char *ntest (void) { return test n; }
+
+class nc
+{
+public:
+int i;
+static int sj;
+};
+}
+
+extern void send (int, int, const void *, int);
+
+void test (int src)
+{
+  int cookie = 1;
+  send(src, c::OPCODE, c::testc (), cookie);
+  send(src, c::OPCODE, s::tests (), cookie);
+  send(src, c::OPCODE, u::testu (), cookie);
+  send(src, c::OPCODE, n::ntest (), cookie);
+}

Re: PING^2: [patch] pr/54508: fix incomplete debug information for class

[Paul_Koning]

Updated patch: there were two existing testcases that needed to be adjusted 
because of this fix.

Ran check RUNTESTFLAGS=dwarf2.exp, no regressions.

paul

ChangeLog:

2012-10-04  Paul Koning  n...@arrl.net

* dwarf2out.c (prune_unused_types_mark): Mark all of parent's
children if parent is a class.

testsuite/ChangeLog:

2012-10-04  Paul Koning  n...@arrl.net

* g++.dg/debug/dwarf2/pr54508.C: New.
* g++.dg/debug/dwarf2/localclass1.C: Expect staticfn1, staticfn2,
method1 in debug output.
* g++.dg/debug/dwarf2/localclass2.C: Likewise.

Index: gcc/dwarf2out.c
===
--- gcc/dwarf2out.c (revision 192048)
+++ gcc/dwarf2out.c (working copy)
@@ -21035,9 +21035,11 @@
 prune_unused_types_mark_generic_parms_dies (die);

 /* We also have to mark its parents as used.
-(But we don't want to mark our parents' kids due to this.)  */
+(But we don't want to mark our parent's kids due to this,
+unless it is a class.)  */
 if (die-die_parent)
-   prune_unused_types_mark (die-die_parent, 0);
+   prune_unused_types_mark (die-die_parent, 
+class_scope_p (die-die_parent));

 /* Mark any referenced nodes.  */
 prune_unused_types_walk_attribs (die);
Index: gcc/testsuite/g++.dg/debug/dwarf2/pr54508.C
===
--- gcc/testsuite/g++.dg/debug/dwarf2/pr54508.C (revision 0)
+++ gcc/testsuite/g++.dg/debug/dwarf2/pr54508.C (revision 0)
@@ -0,0 +1,67 @@
+// PR debug/54508
+// { dg-do compile }
+// { dg-options -g2 -dA -fno-merge-debug-strings }
+
+// { dg-final { scan-assembler \cbase0\\[ \t\]+\[#;/!|@\]+ DW_AT_name 
} }
+// { dg-final { scan-assembler \OPCODE0\\[ \t\]+\[#;/!|@\]+ DW_AT_name 
} }
+// { dg-final { scan-assembler \bi0\\[ \t\]+\[#;/!|@\]+ DW_AT_name } }
+// { dg-final { scan-assembler \si0\\[ \t\]+\[#;/!|@\]+ DW_AT_name } }
+// { dg-final { scan-assembler \f10\\[ \t\]+\[#;/!|@\]+ DW_AT_name } }
+// { dg-final { scan-assembler \f20\\[ \t\]+\[#;/!|@\]+ DW_AT_name } }
+// { dg-final { scan-assembler-not \nc0\\[ \t\]+\# DW_AT_name } }
+
+class cbase
+
+{
+public:
+ static int si;
+int bi;
+};
+
+class c : public cbase
+
+{
+public:
+ enum
+ {
+  OPCODE = 251
+ };
+ int i ;
+ static const char *testc (void) { return foo; }
+};
+
+struct s
+{
+int f1;
+static const char *tests (void) { return test; }
+};
+
+union u
+{
+int f2;
+double d;
+static const char *testu (void) { return test union; }
+};
+
+namespace n 
+{
+const char *ntest (void) { return test n; }
+
+class nc
+{
+public:
+int i;
+static int sj;
+};
+}
+
+extern void send (int, int, const void *, int);
+
+void test (int src)
+{
+  int cookie = 1;
+  send(src, c::OPCODE, c::testc (), cookie);
+  send(src, c::OPCODE, s::tests (), cookie);
+  send(src, c::OPCODE, u::testu (), cookie);
+  send(src, c::OPCODE, n::ntest (), cookie);
+}
Index: gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C
===
--- gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C (revision 192048)
+++ gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C (working copy)
@@ -59,11 +59,11 @@
 // { dg-final { scan-assembler foo\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler staticfn1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler staticfn2\[^\n\r\]*DW_AT_name } }
-// { dg-final { scan-assembler-not staticfn3\[^\n\r\]*DW_AT_name } }
-// { dg-final { scan-assembler-not staticfn4\[^\n\r\]*DW_AT_name } }
+// { dg-final { scan-assembler staticfn3\[^\n\r\]*DW_AT_name } }
+// { dg-final { scan-assembler staticfn4\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler-not staticfn5\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler-not staticfn6\[^\n\r\]*DW_AT_name } }
-// { dg-final { scan-assembler-not method1\[^\n\r\]*DW_AT_name } }
+// { dg-final { scan-assembler method1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg2\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg3\[^\n\r\]*DW_AT_name } }
Index: gcc/testsuite/g++.dg/debug/dwarf2/localclass2.C
===
--- gcc/testsuite/g++.dg/debug/dwarf2/localclass2.C (revision 192048)
+++ gcc/testsuite/g++.dg/debug/dwarf2/localclass2.C (working copy)
@@ -59,11 +59,11 @@
 // { dg-final { scan-assembler foo\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler staticfn1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler staticfn2\[^\n\r\]*DW_AT_name } }
-// { dg-final { scan-assembler-not staticfn3\[^\n\r\]*DW_AT_name } }
-// { dg-final { scan-assembler-not staticfn4\[^\n\r\]*DW_AT_name } }
+// { dg-final { scan-assembler staticfn3\[^\n\r\]*DW_AT_name } }
+// { dg-final { scan-assembler 

Re: PING^2: [patch] pr/54508: fix incomplete debug information for class

[Paul_Koning]

On Oct 4, 2012, at 8:26 PM, Cary Coutant wrote:

 Index: gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C
 ===
 --- gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C (revision 192048)
 +++ gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C (working copy)
 @@ -59,11 +59,11 @@
 // { dg-final { scan-assembler foo\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler staticfn1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler staticfn2\[^\n\r\]*DW_AT_name } }
 -// { dg-final { scan-assembler-not staticfn3\[^\n\r\]*DW_AT_name } }
 -// { dg-final { scan-assembler-not staticfn4\[^\n\r\]*DW_AT_name } }
 +// { dg-final { scan-assembler staticfn3\[^\n\r\]*DW_AT_name } }
 +// { dg-final { scan-assembler staticfn4\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler-not staticfn5\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler-not staticfn6\[^\n\r\]*DW_AT_name } }
 -// { dg-final { scan-assembler-not method1\[^\n\r\]*DW_AT_name } }
 +// { dg-final { scan-assembler method1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg2\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg3\[^\n\r\]*DW_AT_name } }
 
 The fact that these two tests were specifically checking for the
 absence of staticfn3 and staticfn4 leads me to believe that the
 current behavior is deliberate. Jakub, that change was yours (it dates
 back to November 2008). Are you OK with Paul's change?
 
 It seems to me that there are cases where we just want to emit the
 class for the context info (like a namespace, which doesn't have to be
 complete everywhere). Is there a way to tell the debugger that this
 class declaration is incomplete and that it should look elsewhere for
 a full definition?
 
 -cary

Certainly GDB does not currently do that.  As it stands, it uses whatever 
definition it finds first, so depending on which compilation unit's symbols are 
read first, what you see varies unpredictably. If there is a way to express in 
Dwarf-2 the fact that this is an incomplete definition, GDB could presumably be 
changed to take advantage of that.  I have no idea how hard that is.

paul

Re: PING^2: [patch] pr/54508: fix incomplete debug information for class

[Paul_Koning]

On Oct 4, 2012, at 8:26 PM, Cary Coutant wrote:

 Index: gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C
 ===
 --- gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C (revision 192048)
 +++ gcc/testsuite/g++.dg/debug/dwarf2/localclass1.C (working copy)
 @@ -59,11 +59,11 @@
 // { dg-final { scan-assembler foo\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler staticfn1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler staticfn2\[^\n\r\]*DW_AT_name } }
 -// { dg-final { scan-assembler-not staticfn3\[^\n\r\]*DW_AT_name } }
 -// { dg-final { scan-assembler-not staticfn4\[^\n\r\]*DW_AT_name } }
 +// { dg-final { scan-assembler staticfn3\[^\n\r\]*DW_AT_name } }
 +// { dg-final { scan-assembler staticfn4\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler-not staticfn5\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler-not staticfn6\[^\n\r\]*DW_AT_name } }
 -// { dg-final { scan-assembler-not method1\[^\n\r\]*DW_AT_name } }
 +// { dg-final { scan-assembler method1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg1\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg2\[^\n\r\]*DW_AT_name } }
 // { dg-final { scan-assembler arg3\[^\n\r\]*DW_AT_name } }
 
 The fact that these two tests were specifically checking for the
 absence of staticfn3 and staticfn4 leads me to believe that the
 current behavior is deliberate. Jakub, that change was yours (it dates
 back to November 2008). Are you OK with Paul's change?
 
 It seems to me that there are cases where we just want to emit the
 class for the context info (like a namespace, which doesn't have to be
 complete everywhere). Is there a way to tell the debugger that this
 class declaration is incomplete and that it should look elsewhere for
 a full definition?
 
 -cary

The code itself (where I changed dwarf2out.c) is from 2003-02-28, by rth, what 
appears to be the original implementation of the -feliminate-unused-debug-types 
flag.

Looking at Jakub's change from 2008 and PR/27017 it fixes, it looks more like a 
case of much more debug information that was missing and Jakub's change 
corrected that.  It looks like those two testcase files describe the resulting 
behavior, but I don't read the discussion in PR/27017 as saying that having 
staticfn3 omitted was specifically desired. 

paul

Re: RFC: LRA for x86/x86-64 [4/9]

[Paul_Koning]

On Oct 1, 2012, at 2:51 PM, Richard Sandiford wrote:

 ...
 E.g. for MIPS, SImode loads and stores have a displacement range of
 [-32768, 32764], but DImode loads and stores only accept [-32768, 32760].
 So the maximal displacement depends on mode, even though the instruction set
 is pretty regular.

It may be that the case doesn't arise in code GCC generates, but I don't think 
that's true.  The offset field is always a 2's complement 16 bit integer, hence 
in the range -32768..32767.  The alignment required in loading multibyte data 
with aligned load/store instructions applies to the final address, not the 
offset.  For example, if R1 contains 1, then LD r2,32767(r1) will work.

paul

Re: [PATCH v2, rtl-optimization]: Fix PR54457, [x32] Fail to combine 64bit index + constant

[Paul_Koning]

On Sep 27, 2012, at 2:04 PM, Uros Bizjak wrote:

 
 
 
 I agree (subreg:M (op:N A C) 0) to (op:M (subreg:N (A 0)) C) is
 a good transformation, but why do we need to handle as special
 the case where the subreg is itself the operand of a plus or minus?
 I think it should happen regardless of where the subreg occurs.
 
 Don't we need to restrict this to the low part though?
 
 ...
 
 After some off-line discussion with Richard, attached is v2 of the patch.
 
 2012-09-27  Uros Bizjak  ubiz...@gmail.com
 
PR rtl-optimization/54457
* simplify-rtx.c (simplify_subreg):
   Simplify (subreg:SI (op:DI ((x:DI) (y:DI)), 0)
   to (op:SI (subreg:SI (x:DI) 0) (subreg:SI (x:DI) 0)).
 ...

Is it just specific to DI - SI, or is it for any large mode - smaller mode, 
like SI - HI?

paul

Ping: [patch] pr/54508: fix incomplete debug information for class

[Paul_Koning]

Ping...

paul

Begin forwarded message:

 From: paul_kon...@dell.com
 Date: September 20, 2012 4:55:05 PM EDT
 To: gcc-patches@gcc.gnu.org
 Subject: Re: [patch] pr/54508: fix incomplete debug information for class
 
 Attached below is an update to the testcase file, to fix the scan-assembler 
 regexp comment character matching.  This uses the same regexp element that 
 H-P Nilsson used in the fix to nested-3.C two days ago.
 
 By the way, I ran check-g++ for dwarf2.exp on this change, no regressions.
 
 Ok to commit?  
 
   paul
 
 On Sep 17, 2012, at 5:24 PM, paul_kon...@dell.com
 paul_kon...@dell.com wrote:
 
 If the only reference in a source file is to a static method of a class, 
 then GCC would output debug information for the class name but not any of 
 its members or base classes.  The attached patch fixes this by having 
 prune_unused_types_mark mark all of the parent's children if the parent 
 DIE type is for a class.
 
 The associated new testcase verifies this, and also verifies this that 
 references to a function in a namespace do *not* cause other parts of that 
 namespace to be emitted as debug information, but that references to a 
 method in a class (or struct or union) do emit the other information for 
 that class.
 
 Ok to commit?  This would close PR/54508.
 
  paul
 
 ChangeLog:
 
 2012-09-17  Paul Koning  n...@arrl.net
 
  * dwarf2out.c (prune_unused_types_mark): Mark all of parent's
  children if parent is a class.
 
 testsuite/ChangeLog:
 
 2012-09-17  Paul Koning  n...@arrl.net
 
  * g++.dg/debug/dwarf2/pr54508.C: New.
 
 Index: gcc/dwarf2out.c
 ===
 --- gcc/dwarf2out.c  (revision 191408)
 +++ gcc/dwarf2out.c  (working copy)
 @@ -21033,9 +21033,13 @@
  prune_unused_types_mark_generic_parms_dies (die);
 
  /* We also have to mark its parents as used.
 - (But we don't want to mark our parents' kids due to this.)  */
 + (But we don't want to mark our parent's kids due to this,
 + unless it is a class.)  */
  if (die-die_parent)
 -prune_unused_types_mark (die-die_parent, 0);
 +prune_unused_types_mark (die-die_parent, 
 + (die-die_parent-die_tag == DW_TAG_class_type 
 ||
 +  die-die_parent-die_tag == 
 DW_TAG_structure_type ||
 +  die-die_parent-die_tag == 
 DW_TAG_union_type));
 
  /* Mark any referenced nodes.  */
  prune_unused_types_walk_attribs (die);
 Index: gcc/testsuite/g++.dg/debug/dwarf2/pr54508.C
 ===
 --- gcc/testsuite/g++.dg/debug/dwarf2/pr54508.C  (revision 0)
 +++ gcc/testsuite/g++.dg/debug/dwarf2/pr54508.C  (revision 0)
 @@ -0,0 +1,67 @@
 +// PR debug/54508
 +// { dg-do compile }
 +// { dg-options -g2 -dA }
 +
 +// { dg-final { scan-assembler \cbase0\\[ \t\]+\# 
 DW_AT_name\|DW_AT_name: \cbase\ } }
 +// { dg-final { scan-assembler \OPCODE0\\[ \t\]+\# 
 DW_AT_name\|DW_AT_name: \OPCODE\ } }
 +// { dg-final { scan-assembler \bi0\\[ \t\]+\# DW_AT_name } }
 +// { dg-final { scan-assembler \si0\\[ \t\]+\# DW_AT_name } }
 +// { dg-final { scan-assembler \f10\\[ \t\]+\# DW_AT_name } }
 +// { dg-final { scan-assembler \f20\\[ \t\]+\# DW_AT_name } }
 +// { dg-final { scan-assembler-not \nc0\\[ \t\]+\# 
 DW_AT_name\|DW_AT_name: \nc\ } }
 +...
 
 // PR debug/54508
 // { dg-do compile }
 // { dg-options -g2 -dA }
 
 // { dg-final { scan-assembler \cbase0\\[ \t\]+\[#;/!|@\]+ 
 DW_AT_name\|DW_AT_name: \cbase\ } }
 // { dg-final { scan-assembler \OPCODE0\\[ \t\]+\[#;/!|@\]+ 
 DW_AT_name\|DW_AT_name: \OPCODE\ } }
 // { dg-final { scan-assembler \bi0\\[ \t\]+\[#;/!|@\]+ DW_AT_name } }
 // { dg-final { scan-assembler \si0\\[ \t\]+\[#;/!|@\]+ DW_AT_name } }
 // { dg-final { scan-assembler \f10\\[ \t\]+\[#;/!|@\]+ DW_AT_name } }
 // { dg-final { scan-assembler \f20\\[ \t\]+\[#;/!|@\]+ DW_AT_name } }
 // { dg-final { scan-assembler-not \nc0\\[ \t\]+\# 
 DW_AT_name\|DW_AT_name: \nc\ } }
 
 class cbase
 
 {
 public:
 static int si;
int bi;
 };
 
 class c : public cbase
 
 {
 public:
 enum
 {
  OPCODE = 251
 };
 int i ;
 static const char *testc (void) { return foo; }
 };
 
 struct s
 {
int f1;
static const char *tests (void) { return test; }
 };
 
 union u
 {
int f2;
double d;
static const char *testu (void) { return test union; }
 };
 
 namespace n 
 {
const char *ntest (void) { return test n; }
 
class nc
{
public:
int i;
static int sj;
};
 }
 
 extern void send (int, int, const void *, int);
 
 void test (int src)
 {
  int cookie = 1;
  send(src, c::OPCODE, c::testc (), cookie);
  send(src, c::OPCODE, s::tests (), cookie);
  send(src, c::OPCODE, u::testu (), cookie);
  send(src, c::OPCODE, n::ntest (), cookie);
 }
 

[DOC] Update -feliminate-unused-debug-types description

[Paul_Koning]

Currently the description of -feliminate-unused-debug-types says that it is off 
by default.  In fact, it is on by default.  The attached patch corrects the 
documentation to reflect that.

Ok to commit?

paul

2012-09-17  Paul Koning  n...@arrl.net

* doc/invoke.text (-feliminate-unused-debug-types): Update to
reflect that this is enabled by default.

Index: invoke.texi
===
--- invoke.texi (revision 191393)
+++ invoke.texi (working copy)
@@ -324,7 +324,7 @@
 -fdump-tree-storeccp@r{[}-@var{n}@r{]} @gol
 -fdump-final-insns=@var{file} @gol
 -fcompare-debug@r{[}=@var{opts}@r{]}  -fcompare-debug-second @gol
--feliminate-dwarf2-dups -feliminate-unused-debug-types @gol
+-feliminate-dwarf2-dups -fno-eliminate-unused-debug-types @gol
 -feliminate-unused-debug-symbols -femit-class-debug-always @gol
 -fenable-@var{kind}-@var{pass} @gol
 -fenable-@var{kind}-@var{pass}=@var{range-list} @gol
@@ -6192,17 +6192,18 @@
 Print the compiler's built-in specs---and don't do anything else.  (This
 is used when GCC itself is being built.)  @xref{Spec Files}.
 
-@item -feliminate-unused-debug-types
+@item -fno-eliminate-unused-debug-types
 @opindex feliminate-unused-debug-types
-Normally, when producing DWARF 2 output, GCC emits debugging
+@opindex fno-eliminate-unused-debug-types
+Normally, when producing DWARF 2 output, GCC avoids producing debug symbol 
+output for types that are nowhere used in the source file being compiled.
+Sometimes it is useful to have GCC emit debugging
 information for all types declared in a compilation
 unit, regardless of whether or not they are actually used
-in that compilation unit.  Sometimes this is useful, such as
+in that compilation unit, for example 
 if, in the debugger, you want to cast a value to a type that is
 not actually used in your program (but is declared).  More often,
 however, this results in a significant amount of wasted space.
-With this option, GCC avoids producing debug symbol output
-for types that are nowhere used in the source file being compiled.
 @end table
 
 @node Optimize Options

Re: [DOC] Update -feliminate-unused-debug-types description

[Paul_Koning]

On Sep 17, 2012, at 1:20 PM, Ian Lance Taylor wrote:

 On Mon, Sep 17, 2012 at 8:59 AM,  paul_kon...@dell.com wrote:
 
 2012-09-17  Paul Koning  n...@arrl.net
 
* doc/invoke.text (-feliminate-unused-debug-types): Update to
reflect that this is enabled by default.
 
 This is OK.
 
 Thanks.
 
 Ian

Thanks.  Committed.

paul

[patch] pr/54508: fix incomplete debug information for class

[Paul_Koning]

If the only reference in a source file is to a static method of a class, then 
GCC would output debug information for the class name but not any of its 
members or base classes.  The attached patch fixes this by having 
prune_unused_types_mark mark all of the parent's children if the parent DIE 
type is for a class.

The associated new testcase verifies this, and also verifies this that 
references to a function in a namespace do *not* cause other parts of that 
namespace to be emitted as debug information, but that references to a method 
in a class (or struct or union) do emit the other information for that class.

Ok to commit?  This would close PR/54508.

paul

ChangeLog:

2012-09-17  Paul Koning  n...@arrl.net

* dwarf2out.c (prune_unused_types_mark): Mark all of parent's
children if parent is a class.

testsuite/ChangeLog:

2012-09-17  Paul Koning  n...@arrl.net

* g++.dg/debug/dwarf2/pr54508.C: New.

Index: gcc/dwarf2out.c
===
--- gcc/dwarf2out.c (revision 191408)
+++ gcc/dwarf2out.c (working copy)
@@ -21033,9 +21033,13 @@
   prune_unused_types_mark_generic_parms_dies (die);
 
   /* We also have to mark its parents as used.
-(But we don't want to mark our parents' kids due to this.)  */
+(But we don't want to mark our parent's kids due to this,
+unless it is a class.)  */
   if (die-die_parent)
-   prune_unused_types_mark (die-die_parent, 0);
+   prune_unused_types_mark (die-die_parent, 
+(die-die_parent-die_tag == DW_TAG_class_type 
||
+ die-die_parent-die_tag == 
DW_TAG_structure_type ||
+ die-die_parent-die_tag == 
DW_TAG_union_type));
 
   /* Mark any referenced nodes.  */
   prune_unused_types_walk_attribs (die);
Index: gcc/testsuite/g++.dg/debug/dwarf2/pr54508.C
===
--- gcc/testsuite/g++.dg/debug/dwarf2/pr54508.C (revision 0)
+++ gcc/testsuite/g++.dg/debug/dwarf2/pr54508.C (revision 0)
@@ -0,0 +1,67 @@
+// PR debug/54508
+// { dg-do compile }
+// { dg-options -g2 -dA }
+
+// { dg-final { scan-assembler \cbase0\\[ \t\]+\# 
DW_AT_name\|DW_AT_name: \cbase\ } }
+// { dg-final { scan-assembler \OPCODE0\\[ \t\]+\# 
DW_AT_name\|DW_AT_name: \OPCODE\ } }
+// { dg-final { scan-assembler \bi0\\[ \t\]+\# DW_AT_name } }
+// { dg-final { scan-assembler \si0\\[ \t\]+\# DW_AT_name } }
+// { dg-final { scan-assembler \f10\\[ \t\]+\# DW_AT_name } }
+// { dg-final { scan-assembler \f20\\[ \t\]+\# DW_AT_name } }
+// { dg-final { scan-assembler-not \nc0\\[ \t\]+\# 
DW_AT_name\|DW_AT_name: \nc\ } }
+
+class cbase
+
+{
+public:
+ static int si;
+int bi;
+};
+
+class c : public cbase
+
+{
+public:
+ enum
+ {
+  OPCODE = 251
+ };
+ int i ;
+ static const char *testc (void) { return foo; }
+};
+
+struct s
+{
+int f1;
+static const char *tests (void) { return test; }
+};
+
+union u
+{
+int f2;
+double d;
+static const char *testu (void) { return test union; }
+};
+
+namespace n 
+{
+const char *ntest (void) { return test n; }
+
+class nc
+{
+public:
+int i;
+static int sj;
+};
+}
+
+extern void send (int, int, const void *, int);
+
+void test (int src)
+{
+  int cookie = 1;
+  send(src, c::OPCODE, c::testc (), cookie);
+  send(src, c::OPCODE, s::tests (), cookie);
+  send(src, c::OPCODE, u::testu (), cookie);
+  send(src, c::OPCODE, n::ntest (), cookie);
+}

Re: [patch] For alpha-vms, unset flag_jump_tables if flag_pic is nonzero

[Paul_Koning]

It turns out that there is a second target that doesn't define 
ASM_OUTPUT_ADDR_DIFF_ELT: pdp11.  I'll fix that.

The documentation is out of date as a consequence of this patch, because it 
still says that ASM_OUTPUT_ADDR_DIFF_ELT is optional which is no longer the 
case (or not unless you take some other actions as you did in the VAX port).

paul

Re: [patch] For alpha-vms, unset flag_jump_tables if flag_pic is nonzero

[Paul_Koning]

On May 16, 2012, at 1:27 PM, paul_kon...@dell.com
 paul_kon...@dell.com wrote:

 It turns out that there is a second target that doesn't define 
 ASM_OUTPUT_ADDR_DIFF_ELT: pdp11.  I'll fix that.
 
 The documentation is out of date as a consequence of this patch, because it 
 still says that ASM_OUTPUT_ADDR_DIFF_ELT is optional which is no longer the 
 case (or not unless you take some other actions as you did in the VAX port).
 
   paul
 

Now I'm really confused.  I defined the missing macro, and now I no longer get 
an ICE -- but I don't see any output from that macro either.  No jump tables 
with -fpic, instead I get what looks like the no table jump available case 
(decision tree).  Why would that be?

paul

RE: [patch] clean up pdp11.md a bit

[Paul_Koning]

By the way, the compile subset of the testsuite works for pdp11; it has some 
errors which still need cleanup but a large fraction works.

paul

-Original Message-
From: Steven Bosscher [mailto:stevenb@gmail.com] 
Sent: Tuesday, February 14, 2012 5:09 PM
To: Koning, Paul; GCC Patches
Subject: [patch] clean up pdp11.md a bit

Hello,

Just a few cleanups for things I noticed last weekend.

* Constraints on define_expand are never used, remove them (most other ports do 
not have constraints on define_expands either)
* Some patterns have no name, makes debugging a bit harder
* The divmodhi4 expander has been commented out since Day 1 of egcs.
Explain why.

Tested by building the compiler. For pdp11-elf, which is not a supported target 
according to backends.html, but it's not rejected.
Not sure what the right target is to compile for. In any case, I obviously have 
no PDP-11 to test on. But the patch has no changes that impact code generation 
(the constraints were already ignored).

OK for trunk?

Ciao!
Steven

RE: [patch] clean up pdp11.md a bit

[Paul_Koning]

These look fine.  I'll defer to others on whether it should wait to Phase 1.

I had tried to make divmod work but never figured out the reason why it did 
not.  Thanks for answering that question.

As for the subregs that Richard commented on -- I will gladly admit that this 
target isn't all clean yet.  So that goes onto the list of things to work on, 
too.

paul

-Original Message-
From: Steven Bosscher [mailto:stevenb@gmail.com] 
Sent: Tuesday, February 14, 2012 5:09 PM
To: Koning, Paul; GCC Patches
Subject: [patch] clean up pdp11.md a bit

Hello,

Just a few cleanups for things I noticed last weekend.

* Constraints on define_expand are never used, remove them (most other ports do 
not have constraints on define_expands either)
* Some patterns have no name, makes debugging a bit harder
* The divmodhi4 expander has been commented out since Day 1 of egcs.
Explain why.

Tested by building the compiler. For pdp11-elf, which is not a supported target 
according to backends.html, but it's not rejected.
Not sure what the right target is to compile for. In any case, I obviously have 
no PDP-11 to test on. But the patch has no changes that impact code generation 
(the constraints were already ignored).

OK for trunk?

Ciao!
Steven

RE: [Patch,AVR] Print no-return functions as JMP

[Paul_Koning]

There is no real post morten debugging on AVR as there is nothing like core 
dump.

But if there is any kind of debugging at all, you might use the debugger to put 
a breakpoint in abort(), and if so, having that invoked via jmp means you don't 
know who called it.  So you'd want a way to suppress that optimization.

paul

RE: [Patch,AVR] Print no-return functions as JMP

[Paul_Koning]

 You should have a way to turn this off.  Otherwise this makes 
 debugging the call to abort impossible.

What do you propose?

o A command line option that is on per default like
  -mnoreturn-tail-calls or -mjmp-noreturn

o Hard-coded factor out some function names like abort,
  exit, _exit

I'd suggest the first option.  That way you can do this for other similar 
functions like panic().

paul

RE: Commit: RX: Disable extender peepholes at -O3

[Paul_Koning]

  I am checking in the patch below to the mainline and 4.6 branch.  It
  disables the peephole optimizations in the rx.md file that combine a
  load followed by a zero- or sign- extend operation.  The disabling
  only happens at -O3 (or higher) as although the peepholes reduce the
  number of instructions they can introduce pipeline stalls that
  actually make the program slower.  (This is certainly true for the
  coremark test).

Doesn't that mean it should be disabled for any optimization other than 
optimize_size?  It seems surprising to have a size but not speed optimization 
done at -O2.

paul