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cse.c (cse_insn): Calculate src_eqv for ZERO_EXTRACT.

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gcc/ChangeLog:

2015-07-12  Kugan Vivekanandarajah  <kuganv@linaro.org>

	* cse.c (cse_insn): Calculate src_eqv for ZERO_EXTRACT.
	* emit-rtl.c (set_for_reg_notes): Allow ZERO_EXTRACT to set
	REG_EQUAL note.

From-SVN: r225721
This commit is contained in:
Kugan Vivekanandarajah 2015-07-12 11:16:30 +00:00 • committed by Kugan Vivekanandarajah
parent 01169386a0
commit 7f7379f6f4
3 changed files with 50 additions and 8 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2015-07-12 Kugan Vivekanandarajah <kuganv@linaro.org>
* cse.c (cse_insn): Calculate src_eqv for ZERO_EXTRACT.
* emit-rtl.c (set_for_reg_notes): Allow ZERO_EXTRACT to set
REG_EQUAL note.
2015-07-11 Marek Polacek <polacek@redhat.com>
PR middle-end/66353

49
gcc/cse.c
View file

@ -4524,14 +4524,49 @@ cse_insn (rtx_insn *insn)
canonicalize_insn (insn, &sets, n_sets);
/* If this insn has a REG_EQUAL note, store the equivalent value in SRC_EQV,
if different, or if the DEST is a STRICT_LOW_PART. The latter condition
is necessary because SRC_EQV is handled specially for this case, and if
it isn't set, then there will be no equivalence for the destination. */
if different, or if the DEST is a STRICT_LOW_PART/ZERO_EXTRACT. The
latter condition is necessary because SRC_EQV is handled specially for
this case, and if it isn't set, then there will be no equivalence
for the destination. */
if (n_sets == 1 && REG_NOTES (insn) != 0
&& (tem = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0
&& (! rtx_equal_p (XEXP (tem, 0), SET_SRC (sets[0].rtl))
|| GET_CODE (SET_DEST (sets[0].rtl)) == STRICT_LOW_PART))
src_eqv = copy_rtx (XEXP (tem, 0));
&& (tem = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0)
{
if ((! rtx_equal_p (XEXP (tem, 0), SET_SRC (sets[0].rtl)))
|| GET_CODE (SET_DEST (sets[0].rtl)) == STRICT_LOW_PART)
src_eqv = copy_rtx (XEXP (tem, 0));
/* If DEST is of the form ZERO_EXTACT, as in:
(set (zero_extract:SI (reg:SI 119)
(const_int 16 [0x10])
(const_int 16 [0x10]))
(const_int 51154 [0xc7d2]))
REG_EQUAL note will specify the value of register (reg:SI 119) at this
point. Note that this is different from SRC_EQV. We can however
calculate SRC_EQV with the position and width of ZERO_EXTRACT. */
else if (GET_CODE (SET_DEST (sets[0].rtl)) == ZERO_EXTRACT
&& CONST_INT_P (src_eqv)
&& CONST_INT_P (XEXP (SET_DEST (sets[0].rtl), 1))
&& CONST_INT_P (XEXP (SET_DEST (sets[0].rtl), 2)))
{
rtx dest_reg = XEXP (SET_DEST (sets[0].rtl), 0);
rtx width = XEXP (SET_DEST (sets[0].rtl), 1);
rtx pos = XEXP (SET_DEST (sets[0].rtl), 2);
HOST_WIDE_INT val = INTVAL (src_eqv);
HOST_WIDE_INT mask;
unsigned int shift;
if (BITS_BIG_ENDIAN)
shift = GET_MODE_PRECISION (GET_MODE (dest_reg))
- INTVAL (pos) - INTVAL (width);
else
shift = INTVAL (pos);
if (INTVAL (width) == HOST_BITS_PER_WIDE_INT)
mask = ~(HOST_WIDE_INT) 0;
else
mask = ((HOST_WIDE_INT) 1 << INTVAL (width)) - 1;
val = (val >> shift) & mask;
src_eqv = GEN_INT (val);
}
}
/* Set sets[i].src_elt to the class each source belongs to.
Detect assignments from or to volatile things

3
gcc/emit-rtl.c
View file

@ -5221,7 +5221,8 @@ set_for_reg_notes (rtx insn)
reg = SET_DEST (pat);
/* Notes apply to the contents of a STRICT_LOW_PART. */
if (GET_CODE (reg) == STRICT_LOW_PART)
if (GET_CODE (reg) == STRICT_LOW_PART
|| GET_CODE (reg) == ZERO_EXTRACT)
reg = XEXP (reg, 0);
/* Check that we have a register. */