The following avoids creating BIT_FIELD_REF of bitfields in update-address-taken. The patch doesn't implement punning to a full precision integer type but leaves a comment according to that.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed. PR tree-optimization/106934 * tree-ssa.cc (non_rewritable_mem_ref_base): Avoid BIT_FIELD_REFs of bitfields. (maybe_rewrite_mem_ref_base): Likewise. * gfortran.dg/pr106934.f90: New testcase. --- gcc/testsuite/gfortran.dg/pr106934.f90 | 7 +++++++ gcc/tree-ssa.cc | 6 ++++++ 2 files changed, 13 insertions(+) create mode 100644 gcc/testsuite/gfortran.dg/pr106934.f90 diff --git a/gcc/testsuite/gfortran.dg/pr106934.f90 b/gcc/testsuite/gfortran.dg/pr106934.f90 new file mode 100644 index 00000000000..ac58a3e82e3 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/pr106934.f90 @@ -0,0 +1,7 @@ +! { dg-do compile } +! { dg-options "-O" } +subroutine s + logical(1) :: a = .true. + logical(2) :: b + a = transfer(b, a) +end diff --git a/gcc/tree-ssa.cc b/gcc/tree-ssa.cc index 6507348e793..1a93ffdbd64 100644 --- a/gcc/tree-ssa.cc +++ b/gcc/tree-ssa.cc @@ -1459,6 +1459,8 @@ maybe_rewrite_mem_ref_base (tree *tp, bitmap suitable_for_renaming) && (! INTEGRAL_TYPE_P (TREE_TYPE (*tp)) || (wi::to_offset (TYPE_SIZE (TREE_TYPE (*tp))) == TYPE_PRECISION (TREE_TYPE (*tp)))) + && (! INTEGRAL_TYPE_P (TREE_TYPE (sym)) + || type_has_mode_precision_p (TREE_TYPE (sym))) && wi::umod_trunc (wi::to_offset (TYPE_SIZE (TREE_TYPE (*tp))), BITS_PER_UNIT) == 0) { @@ -1531,6 +1533,10 @@ non_rewritable_mem_ref_base (tree ref) && (! INTEGRAL_TYPE_P (TREE_TYPE (base)) || (wi::to_offset (TYPE_SIZE (TREE_TYPE (base))) == TYPE_PRECISION (TREE_TYPE (base)))) + /* ??? Likewise for extracts from bitfields, we'd have + to pun the base object to a size precision mode first. */ + && (! INTEGRAL_TYPE_P (TREE_TYPE (decl)) + || type_has_mode_precision_p (TREE_TYPE (decl))) && wi::umod_trunc (wi::to_offset (TYPE_SIZE (TREE_TYPE (base))), BITS_PER_UNIT) == 0) return NULL_TREE; -- 2.35.3