[40/77] Use scalar_int_mode for extraction_insn fields

insv, extv and eztzv modify or read a field in a register or
memory.  The field always has a scalar integer mode, while the
register or memory either has a scalar integer mode or BLKmode.
The mode of the bit position is also a scalar integer.

This patch uses the type system to make that explicit.

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

gcc/
	* optabs-query.h (extraction_insn::struct_mode): Change type to
	opt_scalar_int_mode and update comment.
	(extraction_insn::field_mode): Change type to scalar_int_mode.
	(extraction_insn::pos_mode): Likewise.
	* combine.c (make_extraction): Update accordingly.
	* optabs-query.c (get_traditional_extraction_insn): Likewise.
	(get_optab_extraction_insn): Likewise.
	* recog.c (simplify_while_replacing): Likewise.
	* expmed.c (narrow_bit_field_mem): Change the type of the mode
	parameter to opt_scalar_int_mode.

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

From-SVN: r251492

1 files changed, 16 insertions, 14 deletions

diff --git a/gcc/expmed.c b/gcc/expmed.c
index 641bc24..dabde4e 100644
--- a/gcc/expmed.c
+++ b/gcc/expmed.c
@@ -411,31 +411,33 @@ flip_storage_order (machine_mode mode, rtx x)
   return result;
 }
 
-/* Adjust bitfield memory MEM so that it points to the first unit of mode
-   MODE that contains a bitfield of size BITSIZE at bit position BITNUM.
-   If MODE is BLKmode, return a reference to every byte in the bitfield.
-   Set *NEW_BITNUM to the bit position of the field within the new memory.  */
+/* If MODE is set, adjust bitfield memory MEM so that it points to the
+   first unit of mode MODE that contains a bitfield of size BITSIZE at
+   bit position BITNUM.  If MODE is not set, return a BLKmode reference
+   to every byte in the bitfield.  Set *NEW_BITNUM to the bit position
+   of the field within the new memory.  */
 
 static rtx
-narrow_bit_field_mem (rtx mem, machine_mode mode,
+narrow_bit_field_mem (rtx mem, opt_scalar_int_mode mode,
 		      unsigned HOST_WIDE_INT bitsize,
 		      unsigned HOST_WIDE_INT bitnum,
 		      unsigned HOST_WIDE_INT *new_bitnum)
 {
-  if (mode == BLKmode)
+  scalar_int_mode imode;
+  if (mode.exists (&imode))
+    {
+      unsigned int unit = GET_MODE_BITSIZE (imode);
+      *new_bitnum = bitnum % unit;
+      HOST_WIDE_INT offset = (bitnum - *new_bitnum) / BITS_PER_UNIT;
+      return adjust_bitfield_address (mem, imode, offset);
+    }
+  else
     {
       *new_bitnum = bitnum % BITS_PER_UNIT;
       HOST_WIDE_INT offset = bitnum / BITS_PER_UNIT;
       HOST_WIDE_INT size = ((*new_bitnum + bitsize + BITS_PER_UNIT - 1)
 			    / BITS_PER_UNIT);
-      return adjust_bitfield_address_size (mem, mode, offset, size);
-    }
-  else
-    {
-      unsigned int unit = GET_MODE_BITSIZE (mode);
-      *new_bitnum = bitnum % unit;
-      HOST_WIDE_INT offset = (bitnum - *new_bitnum) / BITS_PER_UNIT;
-      return adjust_bitfield_address (mem, mode, offset);
+      return adjust_bitfield_address_size (mem, BLKmode, offset, size);
     }
 }