[Bug c/54338] New: internal compiler error: in find_costs_and_classes, at ira-costs.c:1711

[Bug c/54338] New: internal compiler error: in find_costs_and_classes, at ira-costs.c:1711

[xyqi at marvell dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54338

             Bug #: 54338
           Summary: internal compiler error: in find_costs_and_classes, at
                    ira-costs.c:1711
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: xyqi@marvell.com


I did some ARM iwmmxt intrinsic test for mainline gcc with this check-in
r190511 | nickc | 2012-08-19 15:11:35 +0800 (Sun, 19 Aug 2012) | 3 lines

        PR target/54306
        * config/arm/mmintrin.h: Remove spurious #endif.

and encountered an internal compiler error for this simple case,
with option -march=iwmmxt2 -S

#include<mmintrin.h>
__m64 foo(__m64 r, int i)
{
r = _mm_slli_si64(r, i);
return r;
}
internal compiler error: in find_costs_and_classes, at ira-costs.c:1711

While with -O, compiling could pass.

Reproduce:
gcc -march=iwmmxt2 -S bug.i

[Bug c/54338] internal compiler error: in find_costs_and_classes, at ira-costs.c:1711

[xyqi at marvell dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54338

--- Comment #1 from Xinyu Qi <xyqi at marvell dot com> 2012-08-21 01:38:57 UTC ---
Created attachment 28064
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28064
the preprocessed source

[Bug target/54338] internal compiler error: in find_costs_and_classes, at ira-costs.c:1711

[vmakarov at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54338

--- Comment #2 from Vladimir Makarov <vmakarov at gcc dot gnu.org> 2012-08-31 18:35:17 UTC ---
IRA can not find super set of GENERAL_REGS and IWMMXT_GR_REGS.  It should not
happen as ALL_REGS exits as the last resort for this.

GCC documentation contains

@findex ALL_REGS
@findex NO_REGS
In general, each register will belong to several classes.  In fact, one
class must be named @code{ALL_REGS} and contain all the registers.  Another
class must be named @code{NO_REGS} and contain no registers.  Often the
union of two classes will be another class; however, this is not required.

Unfortunately, for some reasons ALL_REGS for ARM port does not contain
IWMMXT_GR_REGS, CC_REG, VFPCC_REG, SFP_REG, and AFP_REG.

I think ARM ALL_REGS should contain really all regs.  If this is not possible
for some reasons, we should fix the documentation and I should make a patch for
IRA fixing it in another way.  But I think the right solution would be fixing
ARM ALL_REGS definition (also probably the right cost should be returned by ARM
targets for different combinations of reg classes).

[Bug target/54338] internal compiler error: in find_costs_and_classes, at ira-costs.c:1711

[janis at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54338

Janis Johnson <janis at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |janis at gcc dot gnu.org

--- Comment #3 from Janis Johnson <janis at gcc dot gnu.org> 2012-09-26 22:57:13 UTC ---
I get the same ICE from current trunk for arm-none-eabi for test
gcc.target/arm/mmx-2.c when "-mcpu=iwmmxt" is added to dg-options.

[Bug target/54338] internal compiler error: in find_costs_and_classes, at ira-costs.c:1711

[janis at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54338

Janis Johnson <janis at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rearnsha at gcc dot gnu.org

--- Comment #4 from Janis Johnson <janis at gcc dot gnu.org> 2013-01-10 00:13:31 UTC ---
Test gcc.target/arm/mmx-2.c still gets this ICE with current mainline.