[8/77] Simplify gen_trunc/extend_conv_libfunc

Replace checks of:

  GET_MODE_CLASS (fmode) != MODE_FLOAT && !DECIMAL_FLOAT_MODE_P (fmode)

with !is_a <scalar_float_mode> and use MODE_CLASS equality/inequality
instead of:

  (GET_MODE_CLASS (tmode) == MODE_FLOAT && DECIMAL_FLOAT_MODE_P (fmode))
  || (GET_MODE_CLASS (fmode) == MODE_FLOAT && DECIMAL_FLOAT_MODE_P (tmode))

and:

  (GET_MODE_CLASS (tmode) == MODE_FLOAT
   && GET_MODE_CLASS (fmode) == MODE_FLOAT)
  || (DECIMAL_FLOAT_MODE_P (fmode) && DECIMAL_FLOAT_MODE_P (tmode))

2017-08-30  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* optabs-libfuncs.c (gen_trunc_conv_libfunc): Use is_a
	<scalar_float_mode>.  Simplify.
	(gen_extend_conv_libfunc): Likewise.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r251459

gcc/ChangeLog

@@ -2,6 +2,14 @@
 	    Alan Hayward  <alan.hayward@arm.com>
 	    David Sherwood  <david.sherwood@arm.com>
 
+	* optabs-libfuncs.c (gen_trunc_conv_libfunc): Use is_a
+	<scalar_float_mode>.  Simplify.
+	(gen_extend_conv_libfunc): Likewise.
+
+2017-08-30  Richard Sandiford  <richard.sandiford@linaro.org>
+	    Alan Hayward  <alan.hayward@arm.com>
+	    David Sherwood  <david.sherwood@arm.com>
+
 	* coretypes.h (scalar_float_mode): New type.
 	* machmode.h (mode_traits::from_int): Use machine_mode if
 	USE_ENUM_MODES is defined.

gcc/optabs-libfuncs.c

@@ -579,24 +579,20 @@ gen_trunc_conv_libfunc (convert_optab tab,
 			machine_mode tmode,
 			machine_mode fmode)
 {
-  if (GET_MODE_CLASS (tmode) != MODE_FLOAT && !DECIMAL_FLOAT_MODE_P (tmode))
-    return;
-  if (GET_MODE_CLASS (fmode) != MODE_FLOAT && !DECIMAL_FLOAT_MODE_P (fmode))
-    return;
-  if (tmode == fmode)
+  scalar_float_mode float_tmode, float_fmode;
+  if (!is_a <scalar_float_mode> (fmode, &float_fmode)
+      || !is_a <scalar_float_mode> (tmode, &float_tmode)
+      || float_tmode == float_fmode)
     return;
 
-  if ((GET_MODE_CLASS (tmode) == MODE_FLOAT && DECIMAL_FLOAT_MODE_P (fmode))
-      || (GET_MODE_CLASS (fmode) == MODE_FLOAT && DECIMAL_FLOAT_MODE_P (tmode)))
-     gen_interclass_conv_libfunc (tab, opname, tmode, fmode);
+  if (GET_MODE_CLASS (float_tmode) != GET_MODE_CLASS (float_fmode))
+    gen_interclass_conv_libfunc (tab, opname, float_tmode, float_fmode);
 
-  if (GET_MODE_PRECISION (fmode) <= GET_MODE_PRECISION (tmode))
+  if (GET_MODE_PRECISION (float_fmode) <= GET_MODE_PRECISION (float_tmode))
     return;
 
-  if ((GET_MODE_CLASS (tmode) == MODE_FLOAT
-       && GET_MODE_CLASS (fmode) == MODE_FLOAT)
-      || (DECIMAL_FLOAT_MODE_P (fmode) && DECIMAL_FLOAT_MODE_P (tmode)))
-    gen_intraclass_conv_libfunc (tab, opname, tmode, fmode);
+  if (GET_MODE_CLASS (float_tmode) == GET_MODE_CLASS (float_fmode))
+    gen_intraclass_conv_libfunc (tab, opname, float_tmode, float_fmode);
 }
 
 /* Pick proper libcall for extend_optab.  We need to chose if we do
@@ -608,23 +604,19 @@ gen_extend_conv_libfunc (convert_optab tab,
 			 machine_mode tmode,
 			 machine_mode fmode)
 {
-  if (GET_MODE_CLASS (tmode) != MODE_FLOAT && !DECIMAL_FLOAT_MODE_P (tmode))
-    return;
-  if (GET_MODE_CLASS (fmode) != MODE_FLOAT && !DECIMAL_FLOAT_MODE_P (fmode))
-    return;
-  if (tmode == fmode)
+  scalar_float_mode float_tmode, float_fmode;
+  if (!is_a <scalar_float_mode> (fmode, &float_fmode)
+      || !is_a <scalar_float_mode> (tmode, &float_tmode)
+      || float_tmode == float_fmode)
     return;
 
-  if ((GET_MODE_CLASS (tmode) == MODE_FLOAT && DECIMAL_FLOAT_MODE_P (fmode))
-      || (GET_MODE_CLASS (fmode) == MODE_FLOAT && DECIMAL_FLOAT_MODE_P (tmode)))
-     gen_interclass_conv_libfunc (tab, opname, tmode, fmode);
+  if (GET_MODE_CLASS (float_tmode) != GET_MODE_CLASS (float_fmode))
+    gen_interclass_conv_libfunc (tab, opname, float_tmode, float_fmode);
 
-  if (GET_MODE_PRECISION (fmode) > GET_MODE_PRECISION (tmode))
+  if (GET_MODE_PRECISION (float_fmode) > GET_MODE_PRECISION (float_tmode))
     return;
 
-  if ((GET_MODE_CLASS (tmode) == MODE_FLOAT
-       && GET_MODE_CLASS (fmode) == MODE_FLOAT)
-      || (DECIMAL_FLOAT_MODE_P (fmode) && DECIMAL_FLOAT_MODE_P (tmode)))
+  if (GET_MODE_CLASS (float_tmode) == GET_MODE_CLASS (float_fmode))
     gen_intraclass_conv_libfunc (tab, opname, tmode, fmode);
 }