Jason, This patch prevents creating out-of-bounds BIT_FIELD_REFs in 3 locations.
It fixes a SIGSEGV (triggered by gimple_fold_indirect_ref_1) in simplify_bitfield_ref. I've added an assert to detect the problematic BIT_FIELD_REF there.
Bootstrapped and reg-tested on x86_64. OK for trunk? Thanks, - Tom 2013-11-26 Tom de Vries <t...@codesourcery.com> Marc Glisse <marc.gli...@inria.fr> PR middle-end/59037 * semantics.c (cxx_fold_indirect_ref): Don't create out-of-bounds BIT_FIELD_REF. * fold-const.c (fold_indirect_ref_1): Don't create out-of-bounds BIT_FIELD_REF. * gimple-fold.c (gimple_fold_indirect_ref): Same. * tree-ssa-forwprop.c (simplify_bitfield_ref): Assert that BIT_FIELD_REF is not out-of-bounds. * g++.dg/pr59037.C: New testcase. * gcc.dg/pr59037.c: Same.
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c index 316834c..71daaa2 100644 --- a/gcc/cp/semantics.c +++ b/gcc/cp/semantics.c @@ -9117,7 +9117,7 @@ cxx_fold_indirect_ref (location_t loc, tree type, tree op0, bool *empty_base) unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT; tree index = bitsize_int (indexi); - if (offset/part_widthi <= TYPE_VECTOR_SUBPARTS (op00type)) + if (offset / part_widthi < TYPE_VECTOR_SUBPARTS (op00type)) return fold_build3_loc (loc, BIT_FIELD_REF, type, op00, part_width, index); diff --git a/gcc/fold-const.c b/gcc/fold-const.c index f91673d..0926626 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -16719,7 +16719,7 @@ fold_indirect_ref_1 (location_t loc, tree type, tree op0) unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT; tree index = bitsize_int (indexi); - if (offset/part_widthi <= TYPE_VECTOR_SUBPARTS (op00type)) + if (offset / part_widthi < TYPE_VECTOR_SUBPARTS (op00type)) return fold_build3_loc (loc, BIT_FIELD_REF, type, op00, part_width, index); diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index 2902e69..7e9ba65 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -3418,7 +3418,7 @@ gimple_fold_indirect_ref (tree t) unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT; tree index = bitsize_int (indexi); if (offset / part_widthi - <= TYPE_VECTOR_SUBPARTS (TREE_TYPE (addrtype))) + < TYPE_VECTOR_SUBPARTS (TREE_TYPE (addrtype))) return fold_build3 (BIT_FIELD_REF, type, TREE_OPERAND (addr, 0), part_width, index); } diff --git a/gcc/testsuite/g++.dg/pr59037.C b/gcc/testsuite/g++.dg/pr59037.C new file mode 100644 index 0000000..fae13c2 --- /dev/null +++ b/gcc/testsuite/g++.dg/pr59037.C @@ -0,0 +1,12 @@ +/* { dg-do compile } */ +/* { dg-options "-O3" } */ + +typedef int v4si __attribute__ ((vector_size (16))); + +int +main (int argc, char** argv) +{ + v4si x = {0,1,2,3}; + x = (v4si) {(x)[3], (x)[2], (x)[1], (x)[0]}; + return x[4]; +} diff --git a/gcc/testsuite/gcc.dg/pr59037.c b/gcc/testsuite/gcc.dg/pr59037.c new file mode 100644 index 0000000..ba3a8ba --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr59037.c @@ -0,0 +1,12 @@ +/* { dg-do compile } */ +/* { dg-options "-O3 -std=gnu99" } */ + +typedef int v4si __attribute__ ((vector_size (16))); + +int +main (int argc, char** argv) +{ + v4si x = {0,1,2,3}; + x = (v4si) {(x)[3], (x)[2], (x)[1], (x)[0]}; + return x[4]; +} diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c index 6e6d115..5d685ef 100644 --- a/gcc/tree-ssa-forwprop.c +++ b/gcc/tree-ssa-forwprop.c @@ -3118,6 +3118,7 @@ simplify_bitfield_ref (gimple_stmt_iterator *gsi) if (TREE_CODE (m) != VECTOR_CST) return false; nelts = VECTOR_CST_NELTS (m); + gcc_assert (idx < nelts); idx = TREE_INT_CST_LOW (VECTOR_CST_ELT (m, idx)); idx %= 2 * nelts; if (idx < nelts)