On Tue, Mar 8, 2011 at 10:43 AM, Mikael Pettersson <mi...@it.uu.se> wrote: > gcc.dg/tree-ssa/ssa-ccp-33.c fails with gcc trunk on m68k-linux: > > ssa-ccp-33.c:(.text+0x2a): undefined reference to `link_error' > ssa-ccp-33.c:(.text+0x2a): undefined reference to `link_error' > FAIL: gcc.dg/tree-ssa/ssa-ccp-33.c (test for excess errors) > ssa-ccp-33.c:(.text+0x2a): undefined reference to `link_error' > > The test case checks that the compiler is able to eliminate a > runtime check that an aligned pointer-to-int remains aligned after > a loop of increments. It uses sizeof to compute the alignment > of int, but on m68k (and possibly others) the alignment of int > is less than its size. The compiler is then unable to eliminate > the broken alignment check, and the call to link_error () is not > removed. > > Fixed by using __alignof__ instead. Regression tested on m68k-linux > where it eliminated the FAIL for gcc.dg/tree-ssa/ssa-ccp-33.c. > Also tested on i686-linux, no changes there. > > Ok for trunk? > > (Richard G. pre-approved this change on the PR entry, however I > cannot commit it myself.)
Committed. Richard. > gcc/testsuite/ > > 2011-03-08 Mikael Pettersson <mi...@it.uu.se> > > PR testsuite/47954 > * gcc.dg/tree-ssa/ssa-ccp-33.c: Use __alignof__ not > sizeof to compute alignment. > > --- gcc-4.6-20110305/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-33.c.~1~ > 2010-08-06 13:47:31.000000000 +0200 > +++ gcc-4.6-20110305/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-33.c 2011-03-08 > 10:34:13.000000000 +0100 > @@ -8,7 +8,7 @@ void foo(int n) > int *p; > for (p = a; n != 0; --n, ++p) > ; > - if ((__SIZE_TYPE__)p & (sizeof (int) - 1)) > + if ((__SIZE_TYPE__)p & (__alignof__ (int) - 1)) > link_error (); > } > int main() >
