if (GET_CODE (op) == SUBREG
&& SUBREG_PROMOTED_VAR_P (op)
&& ! SUBREG_PROMOTED_UNSIGNED_P (op)
- && GET_MODE (XEXP (op, 0)) == mode)
- return XEXP (op, 0);
+ && GET_MODE_SIZE (mode) <= GET_MODE_SIZE (GET_MODE (XEXP (op, 0))))
+ return rtl_hooks.gen_lowpart_no_emit (mode, op);
#if defined(POINTERS_EXTEND_UNSIGNED) && !defined(HAVE_ptr_extend)
if (! POINTERS_EXTEND_UNSIGNED
if (GET_CODE (op) == SUBREG
&& SUBREG_PROMOTED_VAR_P (op)
&& SUBREG_PROMOTED_UNSIGNED_P (op) > 0
- && GET_MODE (XEXP (op, 0)) == mode)
- return XEXP (op, 0);
+ && GET_MODE_SIZE (mode) <= GET_MODE_SIZE (GET_MODE (XEXP (op, 0))))
+ return rtl_hooks.gen_lowpart_no_emit (mode, op);
#if defined(POINTERS_EXTEND_UNSIGNED) && !defined(HAVE_ptr_extend)
if (POINTERS_EXTEND_UNSIGNED > 0
return newx;
if (validate_subreg (outermode, innermostmode,
SUBREG_REG (op), final_offset))
- return gen_rtx_SUBREG (outermode, SUBREG_REG (op), final_offset);
+ {
+ newx = gen_rtx_SUBREG (outermode, SUBREG_REG (op), final_offset);
+ if (SUBREG_PROMOTED_VAR_P (op)
+ && SUBREG_PROMOTED_UNSIGNED_P (op) >= 0
+ && GET_MODE_CLASS (outermode) == MODE_INT
+ && IN_RANGE (GET_MODE_SIZE (outermode),
+ GET_MODE_SIZE (innermode),
+ GET_MODE_SIZE (innermostmode))
+ && subreg_lowpart_p (newx))
+ {
+ SUBREG_PROMOTED_VAR_P (newx) = 1;
+ SUBREG_PROMOTED_UNSIGNED_SET
+ (newx, SUBREG_PROMOTED_UNSIGNED_P (op));
+ }
+ return newx;
+ }
return NULL_RTX;
}
return simplify_gen_binary (ASHIFT, outermode,
XEXP (XEXP (op, 0), 0), XEXP (op, 1));
+ /* Recognize a word extraction from a multi-word subreg. */
+ if ((GET_CODE (op) == LSHIFTRT
+ || GET_CODE (op) == ASHIFTRT)
+ && SCALAR_INT_MODE_P (outermode)
+ && GET_MODE_BITSIZE (outermode) >= BITS_PER_WORD
+ && GET_MODE_BITSIZE (innermode) >= (2 * GET_MODE_BITSIZE (outermode))
+ && GET_CODE (XEXP (op, 1)) == CONST_INT
+ && (INTVAL (XEXP (op, 1)) & (GET_MODE_BITSIZE (outermode) - 1)) == 0
+ && byte == subreg_lowpart_offset (outermode, innermode))
+ {
+ int shifted_bytes = INTVAL (XEXP (op, 1)) / BITS_PER_UNIT;
+ return simplify_gen_subreg (outermode, XEXP (op, 0), innermode,
+ (WORDS_BIG_ENDIAN
+ ? byte - shifted_bytes : byte + shifted_bytes));
+ }
+
return NULL_RTX;
}