[PATCH 48/52] m68k: New hook implementation m68k_c_mode_for_floating_type

[Kewen Lin]

This is to add new port specific hook implementation
m68k_c_mode_for_floating_type, remove macro
LONG_DOUBLE_TYPE_SIZE and add new macro
LONG_DOUBLE_TYPE_MODE which some subtarget can redefine.

gcc/ChangeLog:

        * config/m68k/m68k.cc (m68k_c_mode_for_floating_type): New function.
        (TARGET_C_MODE_FOR_FLOATING_TYPE): New macro.
        * config/m68k/m68k.h (LONG_DOUBLE_TYPE_SIZE): Remove.
        (LONG_DOUBLE_TYPE_MODE): New macro.
        * config/m68k/netbsd-elf.h (LONG_DOUBLE_TYPE_SIZE): Remove.
        (LONG_DOUBLE_TYPE_MODE): New macro.
---
 gcc/config/m68k/m68k.cc      | 16 ++++++++++++++++
 gcc/config/m68k/m68k.h       |  4 ++--
 gcc/config/m68k/netbsd-elf.h |  4 ++--
 3 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/gcc/config/m68k/m68k.cc b/gcc/config/m68k/m68k.cc
index b1c9238949f..79ba4d5343c 100644
--- a/gcc/config/m68k/m68k.cc
+++ b/gcc/config/m68k/m68k.cc
@@ -198,6 +198,7 @@ static machine_mode m68k_promote_function_mode (const_tree, 
machine_mode,
                                                int *, const_tree, int);
 static void m68k_asm_final_postscan_insn (FILE *, rtx_insn *insn, rtx [], int);
 static HARD_REG_SET m68k_zero_call_used_regs (HARD_REG_SET);
+static machine_mode m68k_c_mode_for_floating_type (enum tree_index);
 
 /* Initialize the GCC target structure.  */
 
@@ -365,6 +366,9 @@ static HARD_REG_SET m68k_zero_call_used_regs (HARD_REG_SET);
 #undef TARGET_ZERO_CALL_USED_REGS
 #define TARGET_ZERO_CALL_USED_REGS m68k_zero_call_used_regs
 
+#undef TARGET_C_MODE_FOR_FLOATING_TYPE
+#define TARGET_C_MODE_FOR_FLOATING_TYPE m68k_c_mode_for_floating_type
+
 TARGET_GNU_ATTRIBUTES (m68k_attribute_table,
 {
   /* { name, min_len, max_len, decl_req, type_req, fn_type_req,
@@ -7212,4 +7216,16 @@ m68k_zero_call_used_regs (HARD_REG_SET 
need_zeroed_hardregs)
   return need_zeroed_hardregs;
 }
 
+/* Implement TARGET_C_MODE_FOR_FLOATING_TYPE.  Return XFmode or DFmode
+   for TI_LONG_DOUBLE_TYPE which is for long double type, go with the
+   default one for the others.  */
+
+static machine_mode
+m68k_c_mode_for_floating_type (enum tree_index ti)
+{
+  if (ti == TI_LONG_DOUBLE_TYPE)
+    return LONG_DOUBLE_TYPE_MODE;
+  return default_mode_for_floating_type (ti);
+}
+
 #include "gt-m68k.h"
diff --git a/gcc/config/m68k/m68k.h b/gcc/config/m68k/m68k.h
index 1aa89f1789b..0d571997143 100644
--- a/gcc/config/m68k/m68k.h
+++ b/gcc/config/m68k/m68k.h
@@ -278,8 +278,8 @@ along with GCC; see the file COPYING3.  If not see
 /* "long double" is the same as "double" on ColdFire and fido
    targets.  */
 
-#define LONG_DOUBLE_TYPE_SIZE                  \
-  ((TARGET_COLDFIRE || TARGET_FIDOA) ? 64 : 80)
+#define LONG_DOUBLE_TYPE_MODE                  \
+  ((TARGET_COLDFIRE || TARGET_FIDOA) ? DFmode : XFmode)
 
 #define BITS_BIG_ENDIAN 1
 #define BYTES_BIG_ENDIAN 1
diff --git a/gcc/config/m68k/netbsd-elf.h b/gcc/config/m68k/netbsd-elf.h
index 5239f09b4cc..6fc5ad1a0a6 100644
--- a/gcc/config/m68k/netbsd-elf.h
+++ b/gcc/config/m68k/netbsd-elf.h
@@ -36,8 +36,8 @@ along with GCC; see the file COPYING3.  If not see
   while (0)
 
 /* Don't try using XFmode on the 68010.  */ 
-#undef LONG_DOUBLE_TYPE_SIZE
-#define LONG_DOUBLE_TYPE_SIZE (TARGET_68020 ? 80 : 64)
+#undef LONG_DOUBLE_TYPE_MODE
+#define LONG_DOUBLE_TYPE_MODE (TARGET_68020 ? XFmode : DFmode)
 
 #undef SUBTARGET_EXTRA_SPECS
 #define SUBTARGET_EXTRA_SPECS \
-- 
2.43.0