diff options
| -rw-r--r-- | gcc/fold-const.c | 38 |
1 files changed, 27 insertions, 11 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 796f742..4c86dac 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -71,12 +71,12 @@ static tree optimize_bit_field_compare PROTO((enum tree_code, tree, tree, tree)); static tree decode_field_reference PROTO((tree, int *, int *, enum machine_mode *, int *, - int *, tree *)); + int *, tree *, tree *)); static int all_ones_mask_p PROTO((tree, int)); static int simple_operand_p PROTO((tree)); static tree range_test PROTO((enum tree_code, tree, enum tree_code, enum tree_code, tree, tree, tree)); -static tree unextend PROTO((tree, int, int)); +static tree unextend PROTO((tree, int, int, tree)); static tree fold_truthop PROTO((enum tree_code, tree, tree, tree)); static tree strip_compound_expr PROTO((tree, tree)); @@ -2382,17 +2382,20 @@ optimize_bit_field_compare (code, compare_type, lhs, rhs) *PMASK is set to the mask used. This is either contained in a BIT_AND_EXPR or derived from the width of the field. + *PAND_MASK is set the the mask found in a BIT_AND_EXPR, if any. + Return 0 if this is not a component reference or is one that we can't do anything with. */ static tree decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp, - pvolatilep, pmask) + pvolatilep, pmask, pand_mask) tree exp; int *pbitsize, *pbitpos; enum machine_mode *pmode; int *punsignedp, *pvolatilep; tree *pmask; + tree *pand_mask; { tree and_mask = 0; tree mask, inner, offset; @@ -2439,6 +2442,7 @@ decode_field_reference (exp, pbitsize, pbitpos, pmode, punsignedp, convert (unsigned_type, and_mask), mask)); *pmask = mask; + *pand_mask = and_mask; return inner; } @@ -2621,13 +2625,15 @@ range_test (jcode, type, lo_code, hi_code, var, lo_cst, hi_cst) /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P bit value. Arrange things so the extra bits will be set to zero if and - only if C is signed-extended to its full width. */ + only if C is signed-extended to its full width. If MASK is nonzero, + it is an INTEGER_CST that should be AND'ed with the extra bits. */ static tree -unextend (c, p, unsignedp) +unextend (c, p, unsignedp, mask) tree c; int p; int unsignedp; + tree mask; { tree type = TREE_TYPE (c); int modesize = GET_MODE_BITSIZE (TYPE_MODE (type)); @@ -2646,6 +2652,9 @@ unextend (c, p, unsignedp) temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0); temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0); temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0); + if (mask != 0) + temp = const_binop (BIT_AND_EXPR, temp, convert (TREE_TYPE (c), mask), 0); + return convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0)); } @@ -2699,6 +2708,7 @@ fold_truthop (code, truth_type, lhs, rhs) enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode; enum machine_mode lnmode, rnmode; tree ll_mask, lr_mask, rl_mask, rr_mask; + tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask; tree l_const, r_const; tree type, result; int first_bit, end_bit; @@ -2788,16 +2798,20 @@ fold_truthop (code, truth_type, lhs, rhs) volatilep = 0; ll_inner = decode_field_reference (ll_arg, &ll_bitsize, &ll_bitpos, &ll_mode, - &ll_unsignedp, &volatilep, &ll_mask); + &ll_unsignedp, &volatilep, &ll_mask, + &ll_and_mask); lr_inner = decode_field_reference (lr_arg, &lr_bitsize, &lr_bitpos, &lr_mode, - &lr_unsignedp, &volatilep, &lr_mask); + &lr_unsignedp, &volatilep, &lr_mask, + &lr_and_mask); rl_inner = decode_field_reference (rl_arg, &rl_bitsize, &rl_bitpos, &rl_mode, - &rl_unsignedp, &volatilep, &rl_mask); + &rl_unsignedp, &volatilep, &rl_mask, + &rl_and_mask); rr_inner = decode_field_reference (rr_arg, &rr_bitsize, &rr_bitpos, &rr_mode, - &rr_unsignedp, &volatilep, &rr_mask); + &rr_unsignedp, &volatilep, &rr_mask, + &rr_and_mask); /* It must be true that the inner operation on the lhs of each comparison must be the same if we are to be able to do anything. @@ -2866,7 +2880,8 @@ fold_truthop (code, truth_type, lhs, rhs) if (l_const) { - l_const = unextend (convert (type, l_const), ll_bitsize, ll_unsignedp); + l_const = convert (type, l_const); + l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask); l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0); if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const, fold (build1 (BIT_NOT_EXPR, @@ -2883,7 +2898,8 @@ fold_truthop (code, truth_type, lhs, rhs) } if (r_const) { - r_const = unextend (convert (type, r_const), rl_bitsize, rl_unsignedp); + r_const = convert (type, r_const); + r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask); r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0); if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const, fold (build1 (BIT_NOT_EXPR, |