On 2017.04.03 at 11:16 +0200, Richard Biener wrote: > > The following extends split_address_to_core_and_offset to handle > POINTER_PLUS_EXPR to be able to simplify > (unsigned long) &MEM[(void *)&D.15512 + 12B] - (unsigned long) ((const int > *) &D.15512 + 4) which appears during niter analysis. > > We seem to have various copies of similar code but refactoring didn't > seem appropriate at this stage so I went for the minimal fix. > > Bootstrap and regtest running on x86_64-unknown-linux-gnu. > > Richard. > > 2017-04-03 Richard Biener <rguent...@suse.de> > > PR tree-optimization/80275 > * fold-const.c (split_address_to_core_and_offset): Handle > POINTER_PLUS_EXPR. > > * g++.dg/opt/pr80275.C: New testcase. > > Index: gcc/fold-const.c > =================================================================== > --- gcc/fold-const.c (revision 246642) > +++ gcc/fold-const.c (working copy) > @@ -14341,6 +14341,24 @@ split_address_to_core_and_offset (tree e > &volatilep); > core = build_fold_addr_expr_loc (loc, core); > } > + else if (TREE_CODE (exp) == POINTER_PLUS_EXPR) > + { > + core = TREE_OPERAND (exp, 0); > + STRIP_NOPS (core); > + *pbitpos = 0; > + *poffset = TREE_OPERAND (exp, 1); > + if (TREE_CODE (*poffset) == INTEGER_CST) > + { > + offset_int tem = wi::sext (wi::to_offset (*poffset), > + TYPE_PRECISION (TREE_TYPE (*poffset))); > + tem <<= LOG2_BITS_PER_UNIT; > + if (wi::fits_shwi_p (tem)) > + { > + *pbitpos = tem.to_shwi (); > + *poffset = NULL_TREE; > + } > + } > + } > else > { > core = exp; > Index: gcc/testsuite/g++.dg/opt/pr80275.C > =================================================================== > --- gcc/testsuite/g++.dg/opt/pr80275.C (nonexistent) > +++ gcc/testsuite/g++.dg/opt/pr80275.C (working copy) > @@ -0,0 +1,16 @@ > +// { dg-do compile { target c++14 } } > +// { dg-options "-O2 -fdump-tree-optimized" } > + > +#include <algorithm> > + > +int g() > +{ > + return 1234; > +} > + > +int f2() > +{ > + return std::min({1, g(), 4}); > +} > + > +// { dg-final { scan-tree-dump "return 1;" "optimized" } }
The testcase fails with -fpic, e.g.: https://gcc.gnu.org/ml/gcc-regression/2017-04/msg00002.html So perhaps: diff --git a/gcc/testsuite/g++.dg/opt/pr80275.C b/gcc/testsuite/g++.dg/opt/pr80275.C index 7296a07fb2dd..7d625f2c7757 100644 --- a/gcc/testsuite/g++.dg/opt/pr80275.C +++ b/gcc/testsuite/g++.dg/opt/pr80275.C @@ -1,4 +1,4 @@ -// { dg-do compile { target c++14 } } +// { dg-do compile { target c++14 && nonpic } } // { dg-options "-O2 -fdump-tree-optimized" } #include <algorithm> -- Markus