unsigned HOST_WIDE_INT bitpos = bitnum % unit;
rtx op0 = str_rtx;
int byte_offset;
+ rtx orig_value;
enum machine_mode op_mode = mode_for_extraction (EP_insv, 3);
corresponding size. This can occur on a machine with 64 bit registers
that uses SFmode for float. This can also occur for unaligned float
structure fields. */
+ orig_value = value;
if (GET_MODE_CLASS (GET_MODE (value)) != MODE_INT
&& GET_MODE_CLASS (GET_MODE (value)) != MODE_PARTIAL_INT)
value = gen_lowpart ((GET_MODE (value) == VOIDmode
/* Fetch that unit, store the bitfield in it, then store
the unit. */
tempreg = copy_to_reg (op0);
- store_bit_field (tempreg, bitsize, bitpos, fieldmode, value);
+ store_bit_field (tempreg, bitsize, bitpos, fieldmode, orig_value);
emit_move_insn (op0, tempreg);
return value;
}
return immed_double_const (low, high, mode);
}
\f
+/* Extract a bit field from a memory by forcing the alignment of the
+ memory. This efficient only if the field spans at least 4 boundaries.
+
+ OP0 is the MEM.
+ BITSIZE is the field width; BITPOS is the position of the first bit.
+ UNSIGNEDP is true if the result should be zero-extended. */
+
+static rtx
+extract_force_align_mem_bit_field (rtx op0, unsigned HOST_WIDE_INT bitsize,
+ unsigned HOST_WIDE_INT bitpos,
+ int unsignedp)
+{
+ enum machine_mode mode, dmode;
+ unsigned int m_bitsize, m_size;
+ unsigned int sign_shift_up, sign_shift_dn;
+ rtx base, a1, a2, v1, v2, comb, shift, result, start;
+
+ /* Choose a mode that will fit BITSIZE. */
+ mode = smallest_mode_for_size (bitsize, MODE_INT);
+ m_size = GET_MODE_SIZE (mode);
+ m_bitsize = GET_MODE_BITSIZE (mode);
+
+ /* Choose a mode twice as wide. Fail if no such mode exists. */
+ dmode = mode_for_size (m_bitsize * 2, MODE_INT, false);
+ if (dmode == BLKmode)
+ return NULL;
+
+ do_pending_stack_adjust ();
+ start = get_last_insn ();
+
+ /* At the end, we'll need an additional shift to deal with sign/zero
+ extension. By default this will be a left+right shift of the
+ appropriate size. But we may be able to eliminate one of them. */
+ sign_shift_up = sign_shift_dn = m_bitsize - bitsize;
+
+ if (STRICT_ALIGNMENT)
+ {
+ base = plus_constant (XEXP (op0, 0), bitpos / BITS_PER_UNIT);
+ bitpos %= BITS_PER_UNIT;
+
+ /* We load two values to be concatenate. There's an edge condition
+ that bears notice -- an aligned value at the end of a page can
+ only load one value lest we segfault. So the two values we load
+ are at "base & -size" and "(base + size - 1) & -size". If base
+ is unaligned, the addresses will be aligned and sequential; if
+ base is aligned, the addresses will both be equal to base. */
+
+ a1 = expand_simple_binop (Pmode, AND, force_operand (base, NULL),
+ GEN_INT (-(HOST_WIDE_INT)m_size),
+ NULL, true, OPTAB_LIB_WIDEN);
+ mark_reg_pointer (a1, m_bitsize);
+ v1 = gen_rtx_MEM (mode, a1);
+ set_mem_align (v1, m_bitsize);
+ v1 = force_reg (mode, validize_mem (v1));
+
+ a2 = plus_constant (base, GET_MODE_SIZE (mode) - 1);
+ a2 = expand_simple_binop (Pmode, AND, force_operand (a2, NULL),
+ GEN_INT (-(HOST_WIDE_INT)m_size),
+ NULL, true, OPTAB_LIB_WIDEN);
+ v2 = gen_rtx_MEM (mode, a2);
+ set_mem_align (v2, m_bitsize);
+ v2 = force_reg (mode, validize_mem (v2));
+
+ /* Combine these two values into a double-word value. */
+ if (m_bitsize == BITS_PER_WORD)
+ {
+ comb = gen_reg_rtx (dmode);
+ emit_insn (gen_rtx_CLOBBER (VOIDmode, comb));
+ emit_move_insn (gen_rtx_SUBREG (mode, comb, 0), v1);
+ emit_move_insn (gen_rtx_SUBREG (mode, comb, m_size), v2);
+ }
+ else
+ {
+ if (BYTES_BIG_ENDIAN)
+ comb = v1, v1 = v2, v2 = comb;
+ v1 = convert_modes (dmode, mode, v1, true);
+ if (v1 == NULL)
+ goto fail;
+ v2 = convert_modes (dmode, mode, v2, true);
+ v2 = expand_simple_binop (dmode, ASHIFT, v2, GEN_INT (m_bitsize),
+ NULL, true, OPTAB_LIB_WIDEN);
+ if (v2 == NULL)
+ goto fail;
+ comb = expand_simple_binop (dmode, IOR, v1, v2, NULL,
+ true, OPTAB_LIB_WIDEN);
+ if (comb == NULL)
+ goto fail;
+ }
+
+ shift = expand_simple_binop (Pmode, AND, base, GEN_INT (m_size - 1),
+ NULL, true, OPTAB_LIB_WIDEN);
+ shift = expand_mult (Pmode, shift, GEN_INT (BITS_PER_UNIT), NULL, 1);
+
+ if (bitpos != 0)
+ {
+ if (sign_shift_up <= bitpos)
+ bitpos -= sign_shift_up, sign_shift_up = 0;
+ shift = expand_simple_binop (Pmode, PLUS, shift, GEN_INT (bitpos),
+ NULL, true, OPTAB_LIB_WIDEN);
+ }
+ }
+ else
+ {
+ unsigned HOST_WIDE_INT offset = bitpos / BITS_PER_UNIT;
+ bitpos %= BITS_PER_UNIT;
+
+ /* When strict alignment is not required, we can just load directly
+ from memory without masking. If the remaining BITPOS offset is
+ small enough, we may be able to do all operations in MODE as
+ opposed to DMODE. */
+ if (bitpos + bitsize <= m_bitsize)
+ dmode = mode;
+ comb = adjust_address (op0, dmode, offset);
+
+ if (sign_shift_up <= bitpos)
+ bitpos -= sign_shift_up, sign_shift_up = 0;
+ shift = GEN_INT (bitpos);
+ }
+
+ /* Shift down the double-word such that the requested value is at bit 0. */
+ if (shift != const0_rtx)
+ comb = expand_simple_binop (dmode, unsignedp ? LSHIFTRT : ASHIFTRT,
+ comb, shift, NULL, unsignedp, OPTAB_LIB_WIDEN);
+ if (comb == NULL)
+ goto fail;
+
+ /* If the field exactly matches MODE, then all we need to do is return the
+ lowpart. Otherwise, shift to get the sign bits set properly. */
+ result = force_reg (mode, gen_lowpart (mode, comb));
+
+ if (sign_shift_up)
+ result = expand_simple_binop (mode, ASHIFT, result,
+ GEN_INT (sign_shift_up),
+ NULL_RTX, 0, OPTAB_LIB_WIDEN);
+ if (sign_shift_dn)
+ result = expand_simple_binop (mode, unsignedp ? LSHIFTRT : ASHIFTRT,
+ result, GEN_INT (sign_shift_dn),
+ NULL_RTX, 0, OPTAB_LIB_WIDEN);
+
+ return result;
+
+ fail:
+ delete_insns_since (start);
+ return NULL;
+}
+
/* Extract a bit field that is split across two words
and return an RTX for the result.
if (REG_P (op0) || GET_CODE (op0) == SUBREG)
unit = BITS_PER_WORD;
else
- unit = MIN (MEM_ALIGN (op0), BITS_PER_WORD);
+ {
+ unit = MIN (MEM_ALIGN (op0), BITS_PER_WORD);
+ if (0 && bitsize / unit > 2)
+ {
+ rtx tmp = extract_force_align_mem_bit_field (op0, bitsize, bitpos,
+ unsignedp);
+ if (tmp)
+ return tmp;
+ }
+ }
while (bitsdone < bitsize)
{
static rtx
expand_smod_pow2 (enum machine_mode mode, rtx op0, HOST_WIDE_INT d)
{
- unsigned HOST_WIDE_INT mask;
+ unsigned HOST_WIDE_INT masklow, maskhigh;
rtx result, temp, shift, label;
int logd;
if (signmask)
{
signmask = force_reg (mode, signmask);
- mask = ((HOST_WIDE_INT) 1 << logd) - 1;
+ masklow = ((HOST_WIDE_INT) 1 << logd) - 1;
shift = GEN_INT (GET_MODE_BITSIZE (mode) - logd);
/* Use the rtx_cost of a LSHIFTRT instruction to determine
which instruction sequence to use. If logical right shifts
are expensive the use 2 XORs, 2 SUBs and an AND, otherwise
use a LSHIFTRT, 1 ADD, 1 SUB and an AND. */
-
+
temp = gen_rtx_LSHIFTRT (mode, result, shift);
if (lshr_optab->handlers[mode].insn_code == CODE_FOR_nothing
|| rtx_cost (temp, SET) > COSTS_N_INSNS (2))
NULL_RTX, 1, OPTAB_LIB_WIDEN);
temp = expand_binop (mode, sub_optab, temp, signmask,
NULL_RTX, 1, OPTAB_LIB_WIDEN);
- temp = expand_binop (mode, and_optab, temp, GEN_INT (mask),
+ temp = expand_binop (mode, and_optab, temp, GEN_INT (masklow),
NULL_RTX, 1, OPTAB_LIB_WIDEN);
temp = expand_binop (mode, xor_optab, temp, signmask,
NULL_RTX, 1, OPTAB_LIB_WIDEN);
temp = expand_binop (mode, add_optab, op0, signmask,
NULL_RTX, 1, OPTAB_LIB_WIDEN);
- temp = expand_binop (mode, and_optab, temp, GEN_INT (mask),
+ temp = expand_binop (mode, and_optab, temp, GEN_INT (masklow),
NULL_RTX, 1, OPTAB_LIB_WIDEN);
temp = expand_binop (mode, sub_optab, temp, signmask,
NULL_RTX, 1, OPTAB_LIB_WIDEN);
can avoid an explicit compare operation in the following comparison
against zero. */
- mask = (HOST_WIDE_INT) -1 << (GET_MODE_BITSIZE (mode) - 1)
- | (((HOST_WIDE_INT) 1 << logd) - 1);
+ masklow = ((HOST_WIDE_INT) 1 << logd) - 1;
+ if (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT)
+ {
+ masklow |= (HOST_WIDE_INT) -1 << (GET_MODE_BITSIZE (mode) - 1);
+ maskhigh = -1;
+ }
+ else
+ maskhigh = (HOST_WIDE_INT) -1
+ << (GET_MODE_BITSIZE (mode) - HOST_BITS_PER_WIDE_INT - 1);
- temp = expand_binop (mode, and_optab, op0, GEN_INT (mask), result,
- 1, OPTAB_LIB_WIDEN);
+ temp = expand_binop (mode, and_optab, op0,
+ immed_double_const (masklow, maskhigh, mode),
+ result, 1, OPTAB_LIB_WIDEN);
if (temp != result)
emit_move_insn (result, temp);
temp = expand_binop (mode, sub_optab, result, const1_rtx, result,
0, OPTAB_LIB_WIDEN);
- mask = (HOST_WIDE_INT) -1 << logd;
- temp = expand_binop (mode, ior_optab, temp, GEN_INT (mask), result,
- 1, OPTAB_LIB_WIDEN);
+ masklow = (HOST_WIDE_INT) -1 << logd;
+ maskhigh = -1;
+ temp = expand_binop (mode, ior_optab, temp,
+ immed_double_const (masklow, maskhigh, mode),
+ result, 1, OPTAB_LIB_WIDEN);
temp = expand_binop (mode, add_optab, temp, const1_rtx, result,
0, OPTAB_LIB_WIDEN);
if (temp != result)
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