This provides a type-safe way to ask for a float mode and get it as a
scalar_float_mode.
gcc/
2016-11-24 Richard Sandiford <richard.sandif...@arm.com>
Alan Hayward <alan.hayw...@arm.com>
David Sherwood <david.sherw...@arm.com>
* coretypes.h (opt_scalar_float_mode): New typedef.
* machmode.h (float_mode_for_size): New function.
* emit-rtl.c (double_mode): Delete.
(init_emit_once): Use float_mode_for_size.
* stor-layout.c (layout_type): Likewise.
diff --git a/gcc/coretypes.h b/gcc/coretypes.h
index f4c1859..8341cab 100644
--- a/gcc/coretypes.h
+++ b/gcc/coretypes.h
@@ -58,6 +58,7 @@ typedef const struct rtx_def *const_rtx;
class machine_mode;
class scalar_float_mode;
template<typename> class opt_mode;
+typedef opt_mode<scalar_float_mode> opt_scalar_float_mode;
/* Subclasses of rtx_def, using indentation to show the class
hierarchy, along with the relevant invariant.
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index 3bcafbb..efddad4 100644
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -71,7 +71,6 @@ struct target_rtl *this_target_rtl = &default_target_rtl;
machine_mode byte_mode; /* Mode whose width is BITS_PER_UNIT. */
machine_mode word_mode; /* Mode whose width is BITS_PER_WORD. */
-machine_mode double_mode; /* Mode whose width is DOUBLE_TYPE_SIZE. */
machine_mode ptr_mode; /* Mode whose width is POINTER_SIZE. */
/* Datastructures maintained for currently processed function in RTL form. */
@@ -5864,7 +5863,7 @@ init_emit_once (void)
{
int i;
machine_mode mode;
- machine_mode double_mode;
+ scalar_float_mode double_mode;
/* Initialize the CONST_INT, CONST_WIDE_INT, CONST_DOUBLE,
CONST_FIXED, and memory attribute hash tables. */
@@ -5908,7 +5907,7 @@ init_emit_once (void)
else
const_true_rtx = gen_rtx_CONST_INT (VOIDmode, STORE_FLAG_VALUE);
- double_mode = mode_for_size (DOUBLE_TYPE_SIZE, MODE_FLOAT, 0);
+ double_mode = *float_mode_for_size (DOUBLE_TYPE_SIZE);
real_from_integer (&dconst0, double_mode, 0, SIGNED);
real_from_integer (&dconst1, double_mode, 1, SIGNED);
diff --git a/gcc/machmode.h b/gcc/machmode.h
index 996f991..41a3a00 100644
--- a/gcc/machmode.h
+++ b/gcc/machmode.h
@@ -513,7 +513,16 @@ extern const unsigned char mode_complex[NUM_MACHINE_MODES];
extern machine_mode mode_for_size (unsigned int, enum mode_class, int);
-/* Similar, but find the smallest mode for a given width. */
+/* Return the machine mode to use for a MODE_FLOAT of SIZE bits, if one
+ exists. */
+
+inline opt_scalar_float_mode
+float_mode_for_size (unsigned int size)
+{
+ return dyn_cast <scalar_float_mode> (mode_for_size (size, MODE_FLOAT, 0));
+}
+
+/* Similar to mode_for_size, but find the smallest mode for a given width. */
extern machine_mode smallest_mode_for_size (unsigned int,
enum mode_class);
diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c
index 834cf8b..2cde94e 100644
--- a/gcc/stor-layout.c
+++ b/gcc/stor-layout.c
@@ -2132,14 +2132,16 @@ layout_type (tree type)
break;
case REAL_TYPE:
- /* 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;
+ {
+ /* 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, *float_mode_for_size (TYPE_PRECISION (type)));
+ scalar_float_mode mode = as_a <scalar_float_mode> (TYPE_MODE (type));
+ TYPE_SIZE (type) = bitsize_int (GET_MODE_BITSIZE (mode));
+ TYPE_SIZE_UNIT (type) = size_int (GET_MODE_SIZE (mode));
+ break;
+ }
case FIXED_POINT_TYPE:
/* TYPE_MODE (type) has been set already. */
