Previously decimal floating-point types were created and laid out as binary floating-point types, then the caller changed the mode to a decimal mode later. The problem with that approach is that not all targets support an equivalent binary floating-point mode. When they didn't, we would give the type BLKmode and lay it out as a zero-sized type.
This probably had no effect in practice. If a target doesn't support a binary mode then it's unlikely to support the decimal equivalent either. However, with the stricter mode checking added by later patches, we would assert if a scalar floating- point type didn't have a scalar floating-point mode. Tested on aarch64-linux-gnu, x86_64-linux-gnu and powerpc64-linux-gnu. OK to install? Thanks, Richard [ This patch is part of the SVE series posted here: https://gcc.gnu.org/ml/gcc/2016-11/msg00030.html ] gcc/ 2016-11-16 Richard Sandiford <richard.sandif...@arm.com> Alan Hayward <alan.hayw...@arm.com> David Sherwood <david.sherw...@arm.com> * stor-layout.c (layout_type): Allow the caller to set the mode of a float type. Only choose one here if the mode is still VOIDmode. * tree.c (build_common_tree_nodes): Set the type mode of decimal floats before calling layout_type. * config/rs6000/rs6000.c (rs6000_init_builtins): Likewise. diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c index fa62e2e..a789ea1 100644 --- a/gcc/config/rs6000/rs6000.c +++ b/gcc/config/rs6000/rs6000.c @@ -16793,8 +16793,8 @@ rs6000_init_builtins (void) { ibm128_float_type_node = make_node (REAL_TYPE); TYPE_PRECISION (ibm128_float_type_node) = 128; - layout_type (ibm128_float_type_node); SET_TYPE_MODE (ibm128_float_type_node, IFmode); + layout_type (ibm128_float_type_node); lang_hooks.types.register_builtin_type (ibm128_float_type_node, "__ibm128"); @@ -16813,8 +16813,8 @@ rs6000_init_builtins (void) { ieee128_float_type_node = make_node (REAL_TYPE); TYPE_PRECISION (ibm128_float_type_node) = 128; - layout_type (ieee128_float_type_node); SET_TYPE_MODE (ieee128_float_type_node, KFmode); + layout_type (ieee128_float_type_node); /* If we are not exporting the __float128/_Float128 keywords, we need a keyword to get the types created. Use __ieee128 as the dummy diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c index 9f8efcb..5a4bcf1 100644 --- a/gcc/stor-layout.c +++ b/gcc/stor-layout.c @@ -2135,8 +2135,11 @@ layout_type (tree type) break; case REAL_TYPE: - SET_TYPE_MODE (type, - mode_for_size (TYPE_PRECISION (type), MODE_FLOAT, 0)); + /* Allow the caller to choose the type mode, which is how decimal + floats are distinguished from binary ones. */ + if (TYPE_MODE (type) == VOIDmode) + SET_TYPE_MODE (type, + mode_for_size (TYPE_PRECISION (type), MODE_FLOAT, 0)); TYPE_SIZE (type) = bitsize_int (GET_MODE_BITSIZE (TYPE_MODE (type))); TYPE_SIZE_UNIT (type) = size_int (GET_MODE_SIZE (TYPE_MODE (type))); break; diff --git a/gcc/tree.c b/gcc/tree.c index a4c5b1b..f60f331 100644 --- a/gcc/tree.c +++ b/gcc/tree.c @@ -10385,20 +10385,20 @@ build_common_tree_nodes (bool signed_char) /* Decimal float types. */ dfloat32_type_node = make_node (REAL_TYPE); TYPE_PRECISION (dfloat32_type_node) = DECIMAL32_TYPE_SIZE; - layout_type (dfloat32_type_node); SET_TYPE_MODE (dfloat32_type_node, SDmode); + layout_type (dfloat32_type_node); dfloat32_ptr_type_node = build_pointer_type (dfloat32_type_node); dfloat64_type_node = make_node (REAL_TYPE); TYPE_PRECISION (dfloat64_type_node) = DECIMAL64_TYPE_SIZE; - layout_type (dfloat64_type_node); SET_TYPE_MODE (dfloat64_type_node, DDmode); + layout_type (dfloat64_type_node); dfloat64_ptr_type_node = build_pointer_type (dfloat64_type_node); dfloat128_type_node = make_node (REAL_TYPE); TYPE_PRECISION (dfloat128_type_node) = DECIMAL128_TYPE_SIZE; - layout_type (dfloat128_type_node); SET_TYPE_MODE (dfloat128_type_node, TDmode); + layout_type (dfloat128_type_node); dfloat128_ptr_type_node = build_pointer_type (dfloat128_type_node); complex_integer_type_node = build_complex_type (integer_type_node, true);
