}
break;
}
+ /* If the constant is negative, we cannot simplify this. */
+ if (tree_int_cst_sgn (c) == -1)
+ break;
/* FALLTHROUGH */
case NEGATE_EXPR:
if ((t1 = extract_muldiv (op0, c, code, wide_type, strict_overflow_p))
return omit_one_operand (type, t1, arg0);
}
}
+
+ /* X + (X / CST) * -CST is X % CST. */
+ if (TREE_CODE (arg1) == MULT_EXPR
+ && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
+ && operand_equal_p (arg0,
+ TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0))
+ {
+ tree cst0 = TREE_OPERAND (TREE_OPERAND (arg1, 0), 1);
+ tree cst1 = TREE_OPERAND (arg1, 1);
+ tree sum = fold_binary (PLUS_EXPR, TREE_TYPE (cst1), cst1, cst0);
+ if (sum && integer_zerop (sum))
+ return fold_convert (type,
+ fold_build2 (TRUNC_MOD_EXPR,
+ TREE_TYPE (arg0), arg0, cst0));
+ }
}
/* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the
&& integer_all_onesp (arg0))
return fold_build1 (BIT_NOT_EXPR, type, op1);
+
+ /* X - (X / CST) * CST is X % CST. */
+ if (INTEGRAL_TYPE_P (type)
+ && TREE_CODE (arg1) == MULT_EXPR
+ && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
+ && operand_equal_p (arg0,
+ TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0)
+ && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg1, 0), 1),
+ TREE_OPERAND (arg1, 1), 0))
+ return fold_convert (type,
+ fold_build2 (TRUNC_MOD_EXPR, TREE_TYPE (arg0),
+ arg0, TREE_OPERAND (arg1, 1)));
+
if (! FLOAT_TYPE_P (type))
{
if (integer_zerop (arg0))
&& TREE_CODE (arg1) == INTEGER_CST
&& TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
{
- unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, mlo, mhi;
- int width = TYPE_PRECISION (type);
+ unsigned HOST_WIDE_INT hi1, lo1, hi2, lo2, hi3, lo3, mlo, mhi;
+ int width = TYPE_PRECISION (type), w;
hi1 = TREE_INT_CST_HIGH (TREE_OPERAND (arg0, 1));
lo1 = TREE_INT_CST_LOW (TREE_OPERAND (arg0, 1));
hi2 = TREE_INT_CST_HIGH (arg1);
return fold_build2 (BIT_IOR_EXPR, type,
TREE_OPERAND (arg0, 0), arg1);
- /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2. */
+ /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2,
+ unless (C1 & ~C2) | (C2 & C3) for some C3 is a mask of some
+ mode which allows further optimizations. */
hi1 &= mhi;
lo1 &= mlo;
- if ((hi1 & ~hi2) != hi1 || (lo1 & ~lo2) != lo1)
+ hi2 &= mhi;
+ lo2 &= mlo;
+ hi3 = hi1 & ~hi2;
+ lo3 = lo1 & ~lo2;
+ for (w = BITS_PER_UNIT;
+ w <= width && w <= HOST_BITS_PER_WIDE_INT;
+ w <<= 1)
+ {
+ unsigned HOST_WIDE_INT mask
+ = (unsigned HOST_WIDE_INT) -1 >> (HOST_BITS_PER_WIDE_INT - w);
+ if (((lo1 | lo2) & mask) == mask
+ && (lo1 & ~mask) == 0 && hi1 == 0)
+ {
+ hi3 = 0;
+ lo3 = mask;
+ break;
+ }
+ }
+ if (hi3 != hi1 || lo3 != lo1)
return fold_build2 (BIT_IOR_EXPR, type,
fold_build2 (BIT_AND_EXPR, type,
TREE_OPERAND (arg0, 0),
build_int_cst_wide (type,
- lo1 & ~lo2,
- hi1 & ~hi2)),
+ lo3, hi3)),
arg1);
}
return build_int_cst (type, residue & low);
}
+ /* Fold (X << C1) & C2 into (X << C1) & (C2 | ((1 << C1) - 1))
+ (X >> C1) & C2 into (X >> C1) & (C2 | ~((type) -1 >> C1))
+ if the new mask might be further optimized. */
+ if ((TREE_CODE (arg0) == LSHIFT_EXPR
+ || TREE_CODE (arg0) == RSHIFT_EXPR)
+ && host_integerp (TREE_OPERAND (arg0, 1), 1)
+ && host_integerp (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)))
+ && tree_low_cst (TREE_OPERAND (arg0, 1), 1)
+ < TYPE_PRECISION (TREE_TYPE (arg0))
+ && TYPE_PRECISION (TREE_TYPE (arg0)) <= HOST_BITS_PER_WIDE_INT
+ && tree_low_cst (TREE_OPERAND (arg0, 1), 1) > 0)
+ {
+ unsigned int shiftc = tree_low_cst (TREE_OPERAND (arg0, 1), 1);
+ unsigned HOST_WIDE_INT mask
+ = tree_low_cst (arg1, TYPE_UNSIGNED (TREE_TYPE (arg1)));
+ unsigned HOST_WIDE_INT newmask, zerobits = 0;
+ tree shift_type = TREE_TYPE (arg0);
+
+ if (TREE_CODE (arg0) == LSHIFT_EXPR)
+ zerobits = ((((unsigned HOST_WIDE_INT) 1) << shiftc) - 1);
+ else if (TREE_CODE (arg0) == RSHIFT_EXPR
+ && TYPE_PRECISION (TREE_TYPE (arg0))
+ == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg0))))
+ {
+ unsigned int prec = TYPE_PRECISION (TREE_TYPE (arg0));
+ tree arg00 = TREE_OPERAND (arg0, 0);
+ /* See if more bits can be proven as zero because of
+ zero extension. */
+ if (TREE_CODE (arg00) == NOP_EXPR
+ && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg00, 0))))
+ {
+ tree inner_type = TREE_TYPE (TREE_OPERAND (arg00, 0));
+ if (TYPE_PRECISION (inner_type)
+ == GET_MODE_BITSIZE (TYPE_MODE (inner_type))
+ && TYPE_PRECISION (inner_type) < prec)
+ {
+ prec = TYPE_PRECISION (inner_type);
+ /* See if we can shorten the right shift. */
+ if (shiftc < prec)
+ shift_type = inner_type;
+ }
+ }
+ zerobits = ~(unsigned HOST_WIDE_INT) 0;
+ zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
+ zerobits <<= prec - shiftc;
+ /* For arithmetic shift if sign bit could be set, zerobits
+ can contain actually sign bits, so no transformation is
+ possible, unless MASK masks them all away. In that
+ case the shift needs to be converted into logical shift. */
+ if (!TYPE_UNSIGNED (TREE_TYPE (arg0))
+ && prec == TYPE_PRECISION (TREE_TYPE (arg0)))
+ {
+ if ((mask & zerobits) == 0)
+ shift_type = unsigned_type_for (TREE_TYPE (arg0));
+ else
+ zerobits = 0;
+ }
+ }
+
+ /* ((X << 16) & 0xff00) is (X, 0). */
+ if ((mask & zerobits) == mask)
+ return omit_one_operand (type, build_int_cst (type, 0), arg0);
+
+ newmask = mask | zerobits;
+ if (newmask != mask && (newmask & (newmask + 1)) == 0)
+ {
+ unsigned int prec;
+
+ /* Only do the transformation if NEWMASK is some integer
+ mode's mask. */
+ for (prec = BITS_PER_UNIT;
+ prec < HOST_BITS_PER_WIDE_INT; prec <<= 1)
+ if (newmask == (((unsigned HOST_WIDE_INT) 1) << prec) - 1)
+ break;
+ if (prec < HOST_BITS_PER_WIDE_INT
+ || newmask == ~(unsigned HOST_WIDE_INT) 0)
+ {
+ if (shift_type != TREE_TYPE (arg0))
+ {
+ tem = fold_build2 (TREE_CODE (arg0), shift_type,
+ fold_convert (shift_type,
+ TREE_OPERAND (arg0, 0)),
+ TREE_OPERAND (arg0, 1));
+ tem = fold_convert (type, tem);
+ }
+ else
+ tem = op0;
+ return fold_build2 (BIT_AND_EXPR, type, tem,
+ build_int_cst_type (TREE_TYPE (op1),
+ newmask));
+ }
+ }
+ }
+
goto associate;
case RDIV_EXPR:
strict_overflow_p = false;
if (TREE_CODE (arg1) == LSHIFT_EXPR
&& (TYPE_UNSIGNED (type)
- || tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p)))
+ || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
{
tree sval = TREE_OPERAND (arg1, 0);
if (integer_pow2p (sval) && tree_int_cst_sgn (sval) > 0)
fold_convert (type, arg0), sh_cnt);
}
}
+
+ /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
+ TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
+ if (INTEGRAL_TYPE_P (type)
+ && TYPE_UNSIGNED (type)
+ && code == FLOOR_DIV_EXPR)
+ return fold_build2 (TRUNC_DIV_EXPR, type, op0, op1);
+
/* Fall thru */
case ROUND_DIV_EXPR:
strict_overflow_p = false;
if ((code == TRUNC_MOD_EXPR || code == FLOOR_MOD_EXPR)
&& (TYPE_UNSIGNED (type)
- || tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p)))
+ || tree_expr_nonnegative_warnv_p (op0, &strict_overflow_p)))
{
tree c = arg1;
/* Also optimize A % (C << N) where C is a power of 2,
== (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type))))
return TREE_OPERAND (arg0, 0);
+ /* Fold (X & C2) << C1 into (X << C1) & (C2 << C1)
+ (X & C2) >> C1 into (X >> C1) & (C2 >> C1)
+ if the latter can be further optimized. */
+ if ((code == LSHIFT_EXPR || code == RSHIFT_EXPR)
+ && TREE_CODE (arg0) == BIT_AND_EXPR
+ && TREE_CODE (arg1) == INTEGER_CST
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
+ {
+ tree mask = fold_build2 (code, type,
+ fold_convert (type, TREE_OPERAND (arg0, 1)),
+ arg1);
+ tree shift = fold_build2 (code, type,
+ fold_convert (type, TREE_OPERAND (arg0, 0)),
+ arg1);
+ tem = fold_binary (BIT_AND_EXPR, type, shift, mask);
+ if (tem)
+ return tem;
+ }
+
return NULL_TREE;
case MIN_EXPR:
/* bool_var != 1 becomes !bool_var. */
if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_onep (arg1)
&& code == NE_EXPR)
- return fold_build1 (TRUTH_NOT_EXPR, type, arg0);
+ return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
/* bool_var == 0 becomes !bool_var. */
if (TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE && integer_zerop (arg1)
&& code == EQ_EXPR)
- return fold_build1 (TRUTH_NOT_EXPR, type, arg0);
+ return fold_build1 (TRUTH_NOT_EXPR, type, fold_convert (type, arg0));
/* If this is an equality comparison of the address of two non-weak,
unaliased symbols neither of which are extern (since we do not
tree arg01 = TREE_OPERAND (arg0, 1);
if (TREE_CODE (arg00) == LSHIFT_EXPR
&& integer_onep (TREE_OPERAND (arg00, 0)))
- return
- fold_build2 (code, type,
- build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
- build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
- arg01, TREE_OPERAND (arg00, 1)),
- fold_convert (TREE_TYPE (arg0),
- integer_one_node)),
- arg1);
- else if (TREE_CODE (TREE_OPERAND (arg0, 1)) == LSHIFT_EXPR
- && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0, 1), 0)))
- return
- fold_build2 (code, type,
- build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
- build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
- arg00, TREE_OPERAND (arg01, 1)),
- fold_convert (TREE_TYPE (arg0),
- integer_one_node)),
- arg1);
+ {
+ tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg00),
+ arg01, TREE_OPERAND (arg00, 1));
+ tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
+ build_int_cst (TREE_TYPE (arg0), 1));
+ return fold_build2 (code, type,
+ fold_convert (TREE_TYPE (arg1), tem), arg1);
+ }
+ else if (TREE_CODE (arg01) == LSHIFT_EXPR
+ && integer_onep (TREE_OPERAND (arg01, 0)))
+ {
+ tree tem = fold_build2 (RSHIFT_EXPR, TREE_TYPE (arg01),
+ arg00, TREE_OPERAND (arg01, 1));
+ tem = fold_build2 (BIT_AND_EXPR, TREE_TYPE (arg0), tem,
+ build_int_cst (TREE_TYPE (arg0), 1));
+ return fold_build2 (code, type,
+ fold_convert (TREE_TYPE (arg1), tem), arg1);
+ }
}
/* If this is an NE or EQ comparison of zero against the result of a
OSDN Git Service
