Current mainline gfortran fails to build four SPEC CPU2000 tests on
powerpc64-linux using "-m64 -O2 -ffast-math -funroll-loops". In a
call to is_gimple_stmt it tries to dereference a pointer that the
garbage collector has poisoned. This reduced test case (which can
undoubtedly be made smaller) demonstrates the problem using
--param gcc-min-heapsize=1 for powerpc-linux:
subroutine foo
implicit real*8 (a-h,o-z)
real u(5,60,60,60)
do i = 2, nx-1
x = dble(i-1) / (nx-1)
do m = 1, 5
px = (1.0d+00 - x) * u(m,1,j,k) + x * u(m,nx,j,k)
pz = (1.0d+00 - z) * u(m,i,j,l) + z * u(m,i,j,nz)
u(m,i,j,k) = px + p + pz
end do
end do
return
end
elm3b11% /opt/gcc-nightly/mline/bin/gfortran -c -m64 -O2 -ffast-math
-funroll-loops --param ggc-min-heapsize=1 bug.f
bug.f: In function ‘foo’:
bug.f:1: internal compiler error: Segmentation fault
elm3b11% /opt/gcc-nightly/mline/bin/gfortran -c -m32 -O2 -ffast-math --param
ggc-min-heapsize=1 bug.f
bug.f: In function ‘foo’:
bug.f:1: internal compiler error: Segmentation fault
The failure begins with this patch from dje:
http://gcc.gnu.org/ml/gcc-cvs/2005-04/msg00598.html
--
Summary: use of poisoned ggc memory causes cpu2000 build failures
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: tree-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: janis at gcc dot gnu dot org
CC: dje at gcc dot gnu dot org,gcc-bugs at gcc dot gnu dot
org
GCC build triplet: powerpc-linux
GCC host triplet: powerpc-linux
GCC target triplet: powerpc-linux
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21048
