PR middle-end/48335

	* expr.c (expand_assignment): Handle all possibilities
	if TO_RTX is CONCAT.
	* expmed.c (store_bit_field_1): Avoid trying to create
	invalid SUBREGs.
	(store_split_bit_field): If SUBREG_REG (op0) or
	op0 itself has smaller mode than word, return it
	for offset 0 and const0_rtx for out-of-bounds stores.
	If word is const0_rtx, skip it.

	* gcc.c-torture/compile/pr48335-1.c: New test.
	* gcc.dg/pr48335-1.c: New test.
	* gcc.dg/pr48335-2.c: New test.
	* gcc.dg/pr48335-3.c: New test.
	* gcc.dg/pr48335-4.c: New test.
	* gcc.dg/pr48335-5.c: New test.
	* gcc.dg/pr48335-6.c: New test.
	* gcc.dg/pr48335-7.c: New test.
	* gcc.dg/pr48335-8.c: New test.
	* gcc.target/i386/pr48335-1.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@171855 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 32 insertions, 16 deletions

diff --git a/gcc/expmed.c b/gcc/expmed.c
index 6218f3d4ce8..9458df3747e 100644
--- a/gcc/expmed.c
+++ b/gcc/expmed.c
@@ -418,8 +418,10 @@ store_bit_field_1 (rtx str_rtx, unsigned HOST_WIDE_INT bitsize,
       && bitsize == GET_MODE_BITSIZE (fieldmode)
       && (!MEM_P (op0)
 	  ? ((GET_MODE_SIZE (fieldmode) >= UNITS_PER_WORD
-	     || GET_MODE_SIZE (GET_MODE (op0)) == GET_MODE_SIZE (fieldmode))
-	     && byte_offset % GET_MODE_SIZE (fieldmode) == 0)
+	      || GET_MODE_SIZE (GET_MODE (op0)) == GET_MODE_SIZE (fieldmode))
+	     && ((GET_MODE (op0) == fieldmode && byte_offset == 0)
+		 || validate_subreg (fieldmode, GET_MODE (op0), op0,
+				     byte_offset)))
 	  : (! SLOW_UNALIGNED_ACCESS (fieldmode, MEM_ALIGN (op0))
 	     || (offset * BITS_PER_UNIT % bitsize == 0
 		 && MEM_ALIGN (op0) % GET_MODE_BITSIZE (fieldmode) == 0))))
@@ -479,6 +481,7 @@ store_bit_field_1 (rtx str_rtx, unsigned HOST_WIDE_INT bitsize,
       struct expand_operand ops[2];
       enum insn_code icode = optab_handler (movstrict_optab, fieldmode);
       rtx arg0 = op0;
+      unsigned HOST_WIDE_INT subreg_off;
 
       if (GET_CODE (arg0) == SUBREG)
 	{
@@ -491,15 +494,18 @@ store_bit_field_1 (rtx str_rtx, unsigned HOST_WIDE_INT bitsize,
 	  arg0 = SUBREG_REG (arg0);
 	}
 
-      arg0 = gen_rtx_SUBREG (fieldmode, arg0,
-			     (bitnum % BITS_PER_WORD) / BITS_PER_UNIT
-			     + (offset * UNITS_PER_WORD));
+      subreg_off = (bitnum % BITS_PER_WORD) / BITS_PER_UNIT
+		   + (offset * UNITS_PER_WORD);
+      if (validate_subreg (fieldmode, GET_MODE (arg0), arg0, subreg_off))
+	{
+	  arg0 = gen_rtx_SUBREG (fieldmode, arg0, subreg_off);
 
-      create_fixed_operand (&ops[0], arg0);
-      /* Shrink the source operand to FIELDMODE.  */
-      create_convert_operand_to (&ops[1], value, fieldmode, false);
-      if (maybe_expand_insn (icode, 2, ops))
-	return true;
+	  create_fixed_operand (&ops[0], arg0);
+	  /* Shrink the source operand to FIELDMODE.  */
+	  create_convert_operand_to (&ops[1], value, fieldmode, false);
+	  if (maybe_expand_insn (icode, 2, ops))
+	    return true;
+	}
     }
 
   /* Handle fields bigger than a word.  */
@@ -1045,22 +1051,32 @@ store_split_bit_field (rtx op0, unsigned HOST_WIDE_INT bitsize,
       if (GET_CODE (op0) == SUBREG)
 	{
 	  int word_offset = (SUBREG_BYTE (op0) / UNITS_PER_WORD) + offset;
-	  word = operand_subword_force (SUBREG_REG (op0), word_offset,
-					GET_MODE (SUBREG_REG (op0)));
+	  enum machine_mode sub_mode = GET_MODE (SUBREG_REG (op0));
+	  if (sub_mode != BLKmode && GET_MODE_SIZE (sub_mode) < UNITS_PER_WORD)
+	    word = word_offset ? const0_rtx : op0;
+	  else
+	    word = operand_subword_force (SUBREG_REG (op0), word_offset,
+					  GET_MODE (SUBREG_REG (op0)));
 	  offset = 0;
 	}
       else if (REG_P (op0))
 	{
-	  word = operand_subword_force (op0, offset, GET_MODE (op0));
+	  enum machine_mode op0_mode = GET_MODE (op0);
+	  if (op0_mode != BLKmode && GET_MODE_SIZE (op0_mode) < UNITS_PER_WORD)
+	    word = offset ? const0_rtx : op0;
+	  else
+	    word = operand_subword_force (op0, offset, GET_MODE (op0));
 	  offset = 0;
 	}
       else
 	word = op0;
 
       /* OFFSET is in UNITs, and UNIT is in bits.
-         store_fixed_bit_field wants offset in bytes.  */
-      store_fixed_bit_field (word, offset * unit / BITS_PER_UNIT, thissize,
-			     thispos, part);
+	 store_fixed_bit_field wants offset in bytes.  If WORD is const0_rtx,
+	 it is just an out-of-bounds access.  Ignore it.  */
+      if (word != const0_rtx)
+	store_fixed_bit_field (word, offset * unit / BITS_PER_UNIT, thissize,
+			       thispos, part);
       bitsdone += thissize;
     }
 }