destexp = gen_rtx_PLUS (Pmode, destptr, countreg);
srcexp = gen_rtx_PLUS (Pmode, srcptr, countreg);
}
+ if (CONST_INT_P (count))
+ {
+ count = GEN_INT (INTVAL (count)
+ & ~((HOST_WIDE_INT) GET_MODE_SIZE (mode) - 1));
+ destmem = shallow_copy_rtx (destmem);
+ srcmem = shallow_copy_rtx (srcmem);
+ set_mem_size (destmem, count);
+ set_mem_size (srcmem, count);
+ }
+ else
+ {
+ if (MEM_SIZE (destmem))
+ set_mem_size (destmem, NULL_RTX);
+ if (MEM_SIZE (srcmem))
+ set_mem_size (srcmem, NULL_RTX);
+ }
emit_insn (gen_rep_mov (destptr, destmem, srcptr, srcmem, countreg,
destexp, srcexp));
}
Arguments have same meaning as for previous function */
static void
expand_setmem_via_rep_stos (rtx destmem, rtx destptr, rtx value,
- rtx count,
- enum machine_mode mode)
+ rtx count, enum machine_mode mode,
+ rtx orig_value)
{
rtx destexp;
rtx countreg;
}
else
destexp = gen_rtx_PLUS (Pmode, destptr, countreg);
+ if (orig_value == const0_rtx && CONST_INT_P (count))
+ {
+ count = GEN_INT (INTVAL (count)
+ & ~((HOST_WIDE_INT) GET_MODE_SIZE (mode) - 1));
+ destmem = shallow_copy_rtx (destmem);
+ set_mem_size (destmem, count);
+ }
+ else if (MEM_SIZE (destmem))
+ set_mem_size (destmem, NULL_RTX);
emit_insn (gen_rep_stos (destptr, countreg, destmem, value, destexp));
}
gcc_assert (desired_alignment <= 8);
}
+/* Copy enough from DST to SRC to align DST known to DESIRED_ALIGN.
+ ALIGN_BYTES is how many bytes need to be copied. */
+static rtx
+expand_constant_movmem_prologue (rtx dst, rtx *srcp, rtx destreg, rtx srcreg,
+ int desired_align, int align_bytes)
+{
+ rtx src = *srcp;
+ rtx src_size, dst_size;
+ int off = 0;
+ int src_align_bytes = get_mem_align_offset (src, desired_align * BITS_PER_UNIT);
+ if (src_align_bytes >= 0)
+ src_align_bytes = desired_align - src_align_bytes;
+ src_size = MEM_SIZE (src);
+ dst_size = MEM_SIZE (dst);
+ if (align_bytes & 1)
+ {
+ dst = adjust_automodify_address_nv (dst, QImode, destreg, 0);
+ src = adjust_automodify_address_nv (src, QImode, srcreg, 0);
+ off = 1;
+ emit_insn (gen_strmov (destreg, dst, srcreg, src));
+ }
+ if (align_bytes & 2)
+ {
+ dst = adjust_automodify_address_nv (dst, HImode, destreg, off);
+ src = adjust_automodify_address_nv (src, HImode, srcreg, off);
+ if (MEM_ALIGN (dst) < 2 * BITS_PER_UNIT)
+ set_mem_align (dst, 2 * BITS_PER_UNIT);
+ if (src_align_bytes >= 0
+ && (src_align_bytes & 1) == (align_bytes & 1)
+ && MEM_ALIGN (src) < 2 * BITS_PER_UNIT)
+ set_mem_align (src, 2 * BITS_PER_UNIT);
+ off = 2;
+ emit_insn (gen_strmov (destreg, dst, srcreg, src));
+ }
+ if (align_bytes & 4)
+ {
+ dst = adjust_automodify_address_nv (dst, SImode, destreg, off);
+ src = adjust_automodify_address_nv (src, SImode, srcreg, off);
+ if (MEM_ALIGN (dst) < 4 * BITS_PER_UNIT)
+ set_mem_align (dst, 4 * BITS_PER_UNIT);
+ if (src_align_bytes >= 0)
+ {
+ unsigned int src_align = 0;
+ if ((src_align_bytes & 3) == (align_bytes & 3))
+ src_align = 4;
+ else if ((src_align_bytes & 1) == (align_bytes & 1))
+ src_align = 2;
+ if (MEM_ALIGN (src) < src_align * BITS_PER_UNIT)
+ set_mem_align (src, src_align * BITS_PER_UNIT);
+ }
+ off = 4;
+ emit_insn (gen_strmov (destreg, dst, srcreg, src));
+ }
+ dst = adjust_automodify_address_nv (dst, BLKmode, destreg, off);
+ src = adjust_automodify_address_nv (src, BLKmode, srcreg, off);
+ if (MEM_ALIGN (dst) < (unsigned int) desired_align * BITS_PER_UNIT)
+ set_mem_align (dst, desired_align * BITS_PER_UNIT);
+ if (src_align_bytes >= 0)
+ {
+ unsigned int src_align = 0;
+ if ((src_align_bytes & 7) == (align_bytes & 7))
+ src_align = 8;
+ else if ((src_align_bytes & 3) == (align_bytes & 3))
+ src_align = 4;
+ else if ((src_align_bytes & 1) == (align_bytes & 1))
+ src_align = 2;
+ if (src_align > (unsigned int) desired_align)
+ src_align = desired_align;
+ if (MEM_ALIGN (src) < src_align * BITS_PER_UNIT)
+ set_mem_align (src, src_align * BITS_PER_UNIT);
+ }
+ if (dst_size)
+ set_mem_size (dst, GEN_INT (INTVAL (dst_size) - align_bytes));
+ if (src_size)
+ set_mem_size (dst, GEN_INT (INTVAL (src_size) - align_bytes));
+ *srcp = src;
+ return dst;
+}
+
/* Set enough from DEST to align DEST known to by aligned by ALIGN to
DESIRED_ALIGNMENT. */
static void
gcc_assert (desired_alignment <= 8);
}
+/* Set enough from DST to align DST known to by aligned by ALIGN to
+ DESIRED_ALIGN. ALIGN_BYTES is how many bytes need to be stored. */
+static rtx
+expand_constant_setmem_prologue (rtx dst, rtx destreg, rtx value,
+ int desired_align, int align_bytes)
+{
+ int off = 0;
+ rtx dst_size = MEM_SIZE (dst);
+ if (align_bytes & 1)
+ {
+ dst = adjust_automodify_address_nv (dst, QImode, destreg, 0);
+ off = 1;
+ emit_insn (gen_strset (destreg, dst,
+ gen_lowpart (QImode, value)));
+ }
+ if (align_bytes & 2)
+ {
+ dst = adjust_automodify_address_nv (dst, HImode, destreg, off);
+ if (MEM_ALIGN (dst) < 2 * BITS_PER_UNIT)
+ set_mem_align (dst, 2 * BITS_PER_UNIT);
+ off = 2;
+ emit_insn (gen_strset (destreg, dst,
+ gen_lowpart (HImode, value)));
+ }
+ if (align_bytes & 4)
+ {
+ dst = adjust_automodify_address_nv (dst, SImode, destreg, off);
+ if (MEM_ALIGN (dst) < 4 * BITS_PER_UNIT)
+ set_mem_align (dst, 4 * BITS_PER_UNIT);
+ off = 4;
+ emit_insn (gen_strset (destreg, dst,
+ gen_lowpart (SImode, value)));
+ }
+ dst = adjust_automodify_address_nv (dst, BLKmode, destreg, off);
+ if (MEM_ALIGN (dst) < (unsigned int) desired_align * BITS_PER_UNIT)
+ set_mem_align (dst, desired_align * BITS_PER_UNIT);
+ if (dst_size)
+ set_mem_size (dst, GEN_INT (INTVAL (dst_size) - align_bytes));
+ return dst;
+}
+
/* Given COUNT and EXPECTED_SIZE, decide on codegen of string operation. */
static enum stringop_alg
decide_alg (HOST_WIDE_INT count, HOST_WIDE_INT expected_size, bool memset,
unsigned HOST_WIDE_INT count = 0;
HOST_WIDE_INT expected_size = -1;
int size_needed = 0, epilogue_size_needed;
- int desired_align = 0;
+ int desired_align = 0, align_bytes = 0;
enum stringop_alg alg;
int dynamic_check;
bool need_zero_guard = false;
if (CONST_INT_P (expected_align_exp)
&& INTVAL (expected_align_exp) > align)
align = INTVAL (expected_align_exp);
+ /* ALIGN is the minimum of destination and source alignment, but we care here
+ just about destination alignment. */
+ else if (MEM_ALIGN (dst) > (unsigned HOST_WIDE_INT) align * BITS_PER_UNIT)
+ align = MEM_ALIGN (dst) / BITS_PER_UNIT;
+
if (CONST_INT_P (count_exp))
count = expected_size = INTVAL (count_exp);
if (CONST_INT_P (expected_size_exp) && count == 0)
/* Alignment code needs count to be in register. */
if (CONST_INT_P (count_exp) && desired_align > align)
- count_exp = force_reg (counter_mode (count_exp), count_exp);
+ {
+ if (INTVAL (count_exp) > desired_align
+ && INTVAL (count_exp) > size_needed)
+ {
+ align_bytes
+ = get_mem_align_offset (dst, desired_align * BITS_PER_UNIT);
+ if (align_bytes <= 0)
+ align_bytes = 0;
+ else
+ align_bytes = desired_align - align_bytes;
+ }
+ if (align_bytes == 0)
+ count_exp = force_reg (counter_mode (count_exp), count_exp);
+ }
gcc_assert (desired_align >= 1 && align >= 1);
/* Ensure that alignment prologue won't copy past end of block. */
if (desired_align > align)
{
- /* Except for the first move in epilogue, we no longer know
- constant offset in aliasing info. It don't seems to worth
- the pain to maintain it for the first move, so throw away
- the info early. */
- src = change_address (src, BLKmode, srcreg);
- dst = change_address (dst, BLKmode, destreg);
- expand_movmem_prologue (dst, src, destreg, srcreg, count_exp, align,
- desired_align);
+ if (align_bytes == 0)
+ {
+ /* Except for the first move in epilogue, we no longer know
+ constant offset in aliasing info. It don't seems to worth
+ the pain to maintain it for the first move, so throw away
+ the info early. */
+ src = change_address (src, BLKmode, srcreg);
+ dst = change_address (dst, BLKmode, destreg);
+ expand_movmem_prologue (dst, src, destreg, srcreg, count_exp, align,
+ desired_align);
+ }
+ else
+ {
+ /* If we know how many bytes need to be stored before dst is
+ sufficiently aligned, maintain aliasing info accurately. */
+ dst = expand_constant_movmem_prologue (dst, &src, destreg, srcreg,
+ desired_align, align_bytes);
+ count_exp = plus_constant (count_exp, -align_bytes);
+ count -= align_bytes;
+ }
if (need_zero_guard && !count)
{
/* It is possible that we copied enough so the main loop will not
unsigned HOST_WIDE_INT count = 0;
HOST_WIDE_INT expected_size = -1;
int size_needed = 0, epilogue_size_needed;
- int desired_align = 0;
+ int desired_align = 0, align_bytes = 0;
enum stringop_alg alg;
rtx promoted_val = NULL;
bool force_loopy_epilogue = false;
/* Alignment code needs count to be in register. */
if (CONST_INT_P (count_exp) && desired_align > align)
{
- enum machine_mode mode = SImode;
- if (TARGET_64BIT && (count & ~0xffffffff))
- mode = DImode;
- count_exp = force_reg (mode, count_exp);
+ if (INTVAL (count_exp) > desired_align
+ && INTVAL (count_exp) > size_needed)
+ {
+ align_bytes
+ = get_mem_align_offset (dst, desired_align * BITS_PER_UNIT);
+ if (align_bytes <= 0)
+ align_bytes = 0;
+ else
+ align_bytes = desired_align - align_bytes;
+ }
+ if (align_bytes == 0)
+ {
+ enum machine_mode mode = SImode;
+ if (TARGET_64BIT && (count & ~0xffffffff))
+ mode = DImode;
+ count_exp = force_reg (mode, count_exp);
+ }
}
/* Do the cheap promotion to allow better CSE across the
main loop and epilogue (ie one load of the big constant in the
if (size_needed > 1 || (desired_align > 1 && desired_align > align))
{
epilogue_size_needed = MAX (size_needed - 1, desired_align - align);
- /* Epilogue always copies COUNT_EXP & EPILOGUE_SIZE_NEEDED bytes.
+ /* Epilogue always copies COUNT_EXP & (EPILOGUE_SIZE_NEEDED - 1) bytes.
Make sure it is power of 2. */
epilogue_size_needed = smallest_pow2_greater_than (epilogue_size_needed);
if (desired_align > align)
{
- /* Except for the first move in epilogue, we no longer know
- constant offset in aliasing info. It don't seems to worth
- the pain to maintain it for the first move, so throw away
- the info early. */
- dst = change_address (dst, BLKmode, destreg);
- expand_setmem_prologue (dst, destreg, promoted_val, count_exp, align,
- desired_align);
+ if (align_bytes == 0)
+ {
+ /* Except for the first move in epilogue, we no longer know
+ constant offset in aliasing info. It don't seems to worth
+ the pain to maintain it for the first move, so throw away
+ the info early. */
+ dst = change_address (dst, BLKmode, destreg);
+ expand_setmem_prologue (dst, destreg, promoted_val, count_exp, align,
+ desired_align);
+ }
+ else
+ {
+ /* If we know how many bytes need to be stored before dst is
+ sufficiently aligned, maintain aliasing info accurately. */
+ dst = expand_constant_setmem_prologue (dst, destreg, promoted_val,
+ desired_align, align_bytes);
+ count_exp = plus_constant (count_exp, -align_bytes);
+ count -= align_bytes;
+ }
if (need_zero_guard && !count)
{
/* It is possible that we copied enough so the main loop will not
break;
case rep_prefix_8_byte:
expand_setmem_via_rep_stos (dst, destreg, promoted_val, count_exp,
- DImode);
+ DImode, val_exp);
break;
case rep_prefix_4_byte:
expand_setmem_via_rep_stos (dst, destreg, promoted_val, count_exp,
- SImode);
+ SImode, val_exp);
break;
case rep_prefix_1_byte:
expand_setmem_via_rep_stos (dst, destreg, promoted_val, count_exp,
- QImode);
+ QImode, val_exp);
break;
}
/* Adjust properly the offset of src and dest memory for aliasing. */
git://gcc.gnu.org / gcc.git / commitdiff