[Bug target/41176] New: ICE in reload_cse_simplify_operands at postreload.c:396

[Bug target/41176] New: ICE in reload_cse_simplify_operands at postreload.c:396

[lucier at math dot purdue dot edu]

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with this compiler:

[lucier@lambda-head lib]$ /pkgs/gcc-mainline/bin/gcc -v
Using built-in specs.
Target: powerpc64-unknown-linux-gnu
Configured with: ../../mainline/configure --prefix=/pkgs/gcc-mainline
--enable-languages=c,c++ --enable-stage1-languages=c,c++ --with-cpu=default64
Thread model: posix
gcc version 4.5.0 20090825 (experimental) [trunk revision 151108] (GCC) 

and this command line

 /pkgs/gcc-mainline/libexec/gcc/powerpc64-unknown-linux-gnu/4.5.0/cc1
-fpreprocessed thread.i -quiet -mcpu=970 -m64  -O1 -Wno-unused -version
-fschedule-insns -fno-math-errno -fschedule-insns2 -fno-trapping-math
-fno-strict-aliasing -fwrapv -fomit-frame-pointer -fPIC -fno-common

I get the following error:

thread.i: In function ‘___H_make_2d_thread’:
thread.i:719:1: error: insn does not satisfy its constraints:
(insn 625 411 219 26 thread.i:625 (set (reg:DF 19 19)
        (mem:DF (plus:DI (reg:DI 22 22 [orig:197 D.3836 ] [197])
                (const_int 23 [0x17])) [0 S8 A64])) 357 {*movdf_hardfloat64}
(nil))
thread.i:719:1: internal compiler error: in reload_cse_simplify_operands, at
postreload.c:396

I apologize in advance for the size of the test case, which I will post next.


-- 
           Summary: ICE in reload_cse_simplify_operands at postreload.c:396
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: lucier at math dot purdue dot edu
 GCC build triplet: powerpc64-unknown-linux-gnu
  GCC host triplet: powerpc64-unknown-linux-gnu
GCC target triplet: powerpc64-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] ICE in reload_cse_simplify_operands at postreload.c:396

[lucier at math dot purdue dot edu]

------- Comment #1 from lucier at math dot purdue dot edu  2009-08-27 00:14 -------
Created an attachment (id=18431)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=18431&action=view)
preprocessed source file

I'm not having much luck cutting this down more, sorry.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] ICE in reload_cse_simplify_operands at postreload.c:396

[lucier at math dot purdue dot edu]

------- Comment #2 from lucier at math dot purdue dot edu  2009-09-03 02:37 -------
I thought Vlad's scheduling/register allocation patch here

http://gcc.gnu.org/ml/gcc-patches/2009-09/msg00003.html

which solves PR24319, might fix this problem, but it does not.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] ICE in reload_cse_simplify_operands at postreload.c:396

[ubizjak at gmail dot com]

------- Comment #3 from ubizjak at gmail dot com  2009-10-01 16:39 -------
Can you check if this problem is a regression from 4.2+? Although ICEs are not
welcomed, regression status would put more weight on the PR.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] ICE in reload_cse_simplify_operands at postreload.c:396

[lucier at math dot purdue dot edu]

------- Comment #4 from lucier at math dot purdue dot edu  2009-10-01 19:37 -------
There is no ICE when compiling thread.i with gcc-4.2.4:

[lucier@lambda-head ~/Desktop]$
/pkgs/gcc-4.2.4/libexec/gcc/powerpc64-unknown-linux-gnu/4.2.4/cc1
-fpreprocessed thread.i -quiet -mcpu=970 -m64 -O1 -Wno-unused -version
-fschedule-insns -fno-math-errno -fschedule-insns2 -fno-trapping-math
-fno-strict-aliasing -fwrapv -fomit-frame-pointer -fPIC -fno-common
GNU C version 4.2.4 (powerpc64-unknown-linux-gnu)
        compiled by GNU C version 4.2.4.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 833ac11fd00fa57fe0c37f258e543a62
[lucier@lambda-head ~/Desktop]$ /pkgs/gcc-4.2.4/bin/gcc -v
Using built-in specs.
Target: powerpc64-unknown-linux-gnu
Configured with: ../../gcc-4.2.4/configure --enable-languages=c
--prefix=/pkgs/gcc-4.2.4 --enable-checking=release
Thread model: posix
gcc version 4.2.4


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] ICE in reload_cse_simplify_operands at postreload.c:396

[lucier at math dot purdue dot edu]

------- Comment #5 from lucier at math dot purdue dot edu  2009-10-01 19:43 -------
No ICE with 4.3.3, either, but there is an ICE with

Target: ppc64-redhat-linux
gcc version 4.4.1 20090725 (Red Hat 4.4.1-2) (GCC) 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] [4.4/4.5 Regression] ICE in reload_cse_simplify_operands at postreload.c:396

[ubizjak at gmail dot com]

------- Comment #6 from ubizjak at gmail dot com  2009-10-01 19:57 -------
Confirmed, regression.


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2009-10-01 19:57:34
               date|                            |
            Summary|ICE in                      |[4.4/4.5 Regression] ICE in
                   |reload_cse_simplify_operands|reload_cse_simplify_operands
                   |at postreload.c:396         |at postreload.c:396
   Target Milestone|---                         |4.4.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] [4.4/4.5 Regression] ICE in reload_cse_simplify_operands at postreload.c:396

[jakub at gcc dot gnu dot org]

------- Comment #7 from jakub at gcc dot gnu dot org  2009-10-08 07:43 -------
Created an attachment (id=18748)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=18748&action=view)
pr41176.i

Smaller testcase for 4.4 branch.  ICEs with -m64 -O1 -fschedule-insns -fwrapv.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] [4.4/4.5 Regression] ICE in reload_cse_simplify_operands at postreload.c:396

[jakub at gcc dot gnu dot org]

------- Comment #8 from jakub at gcc dot gnu dot org  2009-10-08 13:33 -------
This is on (set (reg:DF X) (mem:DF ((plus:DI (reg:DI Y) (const_int 3)))).
When X is still a pseudo, this is considered valid, as lfd accept any offset,
but when RA chooses to assign X to a GPR register, the address doesn't match
the Y constraint in movdf_hardfloat64.  Is this a bug in reload that it doesn't
attempt to force the address into a register, or in target description that it
should tell reload to do so somehow?  Or does the backend need to be able to
handle these, perhaps by forcing splitting of it?
ld X,disp(Y) for (disp & 3) != 0 could be splitted into addi X,Y,disp;ld
X,0(X),
for std X,disp(Y), (disp & 3) != 0 if X != Y perhaps addi Y,Y,disp;std
X,0(Y);adddi Y,Y,-disp but for std X,disp(Y) I have no idea if there are no
scratch regs available.


-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |uweigand at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] [4.4/4.5 Regression] ICE in reload_cse_simplify_operands at postreload.c:396

[uweigand at gcc dot gnu dot org]

------- Comment #9 from uweigand at gcc dot gnu dot org  2009-10-08 18:39 -------
(In reply to comment #8)
> This is on (set (reg:DF X) (mem:DF ((plus:DI (reg:DI Y) (const_int 3)))).
> When X is still a pseudo, this is considered valid, as lfd accept any offset,
> but when RA chooses to assign X to a GPR register, the address doesn't match
> the Y constraint in movdf_hardfloat64.  Is this a bug in reload that it doesn't
> attempt to force the address into a register, or in target description that it
> should tell reload to do so somehow?  Or does the backend need to be able to
> handle these, perhaps by forcing splitting of it?

If reload were fixing up this insn, it would indeed have to make sure that
the Y -> r constraints are respected, e.g. by reloading the address.

However, this whole insn is *generated* by reload, in order to load a
value into a reload register.   Unfortunately, for such reload insns
(which are simple moves), reload will simply assume they must be supported
by the target, unless there is a secondary reload for this case.

To fix this, I guess the rs6000 backend either has to accept the insn
and implement it via splitting, or else register a secondary reload for
this case (which is also able to request scratch registers).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] [4.4/4.5 Regression] ICE in reload_cse_simplify_operands at postreload.c:396

[jakub at gcc dot gnu dot org]

-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.4.2                       |4.4.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] [4.4/4.5 Regression] ICE in reload_cse_simplify_operands at postreload.c:396

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] [4.4/4.5 Regression] ICE in reload_cse_simplify_operands at postreload.c:396

[jakub at gcc dot gnu dot org]

-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.4.3                       |4.4.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] [4.4/4.5 Regression] ICE in reload_cse_simplify_operands at postreload.c:396

[pinskia at gcc dot gnu dot org]

------- Comment #10 from pinskia at gcc dot gnu dot org  2010-03-02 19:42 -------
The original testcase still ICEs, just not the reduced testcase.

On the trunk, the original testcase has:
(insn 218 217 219 26 t.c:624 (set (reg/v:DF 203 [ ___F64V2 ])
        (mem:DF (plus:DI (reg:DI 197 [ D.2974 ])
                (const_int 39 [0x27])) [0 S8 A64])) 345 {*movdf_hardfloat64}
(nil))

Before ra.
After reload we have:
(insn 624 217 218 26 t.c:624 (set (reg:DF 21 21)
        (mem:DF (plus:DI (reg:DI 22 22 [orig:197 D.2974 ] [197])
                (const_int 39 [0x27])) [0 S8 A64])) 345 {*movdf_hardfloat64}
(nil))

I don't see where reload is creating the whole instruction; maybe I am
misunderstanding that statement.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] [4.4/4.5 Regression] ICE in reload_cse_simplify_operands at postreload.c:396

[uweigand at gcc dot gnu dot org]

------- Comment #11 from uweigand at gcc dot gnu dot org  2010-03-02 19:56 -------
(In reply to comment #10)
> I don't see where reload is creating the whole instruction; maybe I am
> misunderstanding that statement.

Well, after reload you have insn 624, which presumably didn't exist before. 
This was inserted by reload before the (original) insn 218 -- you didn't show
the fixed-up version of insn 218 after reload, but I'm assuming it's probably a
register-to-register (or -to-memory) move from the reload register (reg:DF 21)
into whatever the register allocator has chosen to hold (reg/v:DF 203).

The new insn 624 is not in any way a "fixed up" version of insn 218.  Instead,
it is a reload insn that was generated by reload to load some value (in this
case the (mem:DF ...)) into some reload register.  (That this happens to look
similar to insn 218 before reload is just a coincidence.)  As I mentioned,
reload by default assumes that any move of any legitimate operand into any
register is always valid and can by performed by a simple set.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176

[Bug target/41176] [4.4/4.5/4.6 Regression] ICE in reload_cse_simplify_operands at postreload.c:396

[jakub at gcc dot gnu dot org]

-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.4.4                       |4.4.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41176