arm.c (arm_override_options): Add unaligned_access support.

	gcc/
	* config/arm/arm.c (arm_override_options): Add unaligned_access
	support.
	(arm_file_start): Emit attribute for unaligned access as
	appropriate.
	* config/arm/arm.md (UNSPEC_UNALIGNED_LOAD)
	(UNSPEC_UNALIGNED_STORE): Add constants for unspecs.
	(insv, extzv): Add unaligned-access support.
	(extv): Change to expander. Likewise.
	(extzv_t1, extv_regsi): Add helpers.
	(unaligned_loadsi, unaligned_loadhis, unaligned_loadhiu)
	(unaligned_storesi, unaligned_storehi): New.
	(*extv_reg): New (previous extv implementation).
	* config/arm/arm.opt (munaligned_access): Add option.
	* config/arm/constraints.md (Uw): New constraint.
	* expmed.c (store_bit_field_1): Adjust bitfield numbering according
	to size of access, not size of unit, when BITS_BIG_ENDIAN !=
	BYTES_BIG_ENDIAN. Don't use bitfield accesses for
	volatile accesses when -fstrict-volatile-bitfields is in effect.
	(extract_bit_field_1): Likewise.

From-SVN: r178852

1 files changed, 26 insertions, 13 deletions

diff --git a/gcc/expmed.c b/gcc/expmed.c
index 0047cd09076..1528fbb1112 100644
--- a/gcc/expmed.c
+++ b/gcc/expmed.c
@@ -620,6 +620,10 @@ store_bit_field_1 (rtx str_rtx, unsigned HOST_WIDE_INT bitsize,
       && GET_MODE (value) != BLKmode
       && bitsize > 0
       && GET_MODE_BITSIZE (op_mode) >= bitsize
+      /* Do not use insv for volatile bitfields when
+         -fstrict-volatile-bitfields is in effect.  */
+      && !(MEM_P (op0) && MEM_VOLATILE_P (op0)
+	   && flag_strict_volatile_bitfields > 0)
       && ! ((REG_P (op0) || GET_CODE (op0) == SUBREG)
 	    && (bitsize + bitpos > GET_MODE_BITSIZE (op_mode))))
     {
@@ -659,19 +663,21 @@ store_bit_field_1 (rtx str_rtx, unsigned HOST_WIDE_INT bitsize,
 	  copy_back = true;
 	}
 
-      /* On big-endian machines, we count bits from the most significant.
-	 If the bit field insn does not, we must invert.  */
-
-      if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
-	xbitpos = unit - bitsize - xbitpos;
-
       /* We have been counting XBITPOS within UNIT.
 	 Count instead within the size of the register.  */
-      if (BITS_BIG_ENDIAN && !MEM_P (xop0))
+      if (BYTES_BIG_ENDIAN && !MEM_P (xop0))
 	xbitpos += GET_MODE_BITSIZE (op_mode) - unit;
 
       unit = GET_MODE_BITSIZE (op_mode);
 
+      /* If BITS_BIG_ENDIAN is zero on a BYTES_BIG_ENDIAN machine, we count
+         "backwards" from the size of the unit we are inserting into.
+	 Otherwise, we count bits from the most significant on a
+	 BYTES/BITS_BIG_ENDIAN machine.  */
+
+      if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
+	xbitpos = unit - bitsize - xbitpos;
+
       /* Convert VALUE to op_mode (which insv insn wants) in VALUE1.  */
       value1 = value;
       if (GET_MODE (value) != op_mode)
@@ -1507,6 +1513,10 @@ extract_bit_field_1 (rtx str_rtx, unsigned HOST_WIDE_INT bitsize,
   if (ext_mode != MAX_MACHINE_MODE
       && bitsize > 0
       && GET_MODE_BITSIZE (ext_mode) >= bitsize
+      /* Do not use extv/extzv for volatile bitfields when
+         -fstrict-volatile-bitfields is in effect.  */
+      && !(MEM_P (op0) && MEM_VOLATILE_P (op0)
+	   && flag_strict_volatile_bitfields > 0)
       /* If op0 is a register, we need it in EXT_MODE to make it
 	 acceptable to the format of ext(z)v.  */
       && !(GET_CODE (op0) == SUBREG && GET_MODE (op0) != ext_mode)
@@ -1528,17 +1538,20 @@ extract_bit_field_1 (rtx str_rtx, unsigned HOST_WIDE_INT bitsize,
 	/* Get ref to first byte containing part of the field.  */
 	xop0 = adjust_address (xop0, byte_mode, xoffset);
 
-      /* On big-endian machines, we count bits from the most significant.
-	 If the bit field insn does not, we must invert.  */
-      if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
-	xbitpos = unit - bitsize - xbitpos;
-
       /* Now convert from counting within UNIT to counting in EXT_MODE.  */
-      if (BITS_BIG_ENDIAN && !MEM_P (xop0))
+      if (BYTES_BIG_ENDIAN && !MEM_P (xop0))
 	xbitpos += GET_MODE_BITSIZE (ext_mode) - unit;
 
       unit = GET_MODE_BITSIZE (ext_mode);
 
+      /* If BITS_BIG_ENDIAN is zero on a BYTES_BIG_ENDIAN machine, we count
+         "backwards" from the size of the unit we are extracting from.
+	 Otherwise, we count bits from the most significant on a
+	 BYTES/BITS_BIG_ENDIAN machine.  */
+
+      if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
+	xbitpos = unit - bitsize - xbitpos;
+
       if (xtarget == 0)
 	xtarget = xspec_target = gen_reg_rtx (tmode);