OpenE2K
/
gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

simplify-rtx: Handle truncate of extract 

simplify_truncation changes the truncation of many operations into
the operation on the truncation.  This patch makes this code also
handle extracts.


	* simplify-rtx.c (simplify_truncation): Handle truncate of zero_extract
	and sign_extract.

From-SVN: r242946
This commit is contained in:
Segher Boessenkool 2016-11-29 02:48:30 +01:00 committed by Segher Boessenkool
parent deb2bb610e
commit 48cf0e51e9
2 changed files with 35 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
gcc/ChangeLog
View File

@ -1,3 +1,8 @@
2016-11-28 Segher Boessenkool <segher@kernel.crashing.org>
* simplify-rtx.c (simplify_truncation): Handle truncate of zero_extract
and sign_extract.
2016-11-28 Uros Bizjak <ubizjak@gmail.com>
* config/i386/i386.md (*and<mode>_1): Merge insn pattern from

30
gcc/simplify-rtx.c
View File

@ -747,6 +747,36 @@ simplify_truncation (machine_mode mode, rtx op,
}
}
/* Turn (truncate:M1 (*_extract:M2 (reg:M2) (len) (pos))) into
(*_extract:M1 (truncate:M1 (reg:M2)) (len) (pos')) if possible without
changing len. */
if ((GET_CODE (op) == ZERO_EXTRACT || GET_CODE (op) == SIGN_EXTRACT)
&& REG_P (XEXP (op, 0))
&& CONST_INT_P (XEXP (op, 1))
&& CONST_INT_P (XEXP (op, 2)))
{
rtx op0 = XEXP (op, 0);
unsigned HOST_WIDE_INT len = UINTVAL (XEXP (op, 1));
unsigned HOST_WIDE_INT pos = UINTVAL (XEXP (op, 2));
if (BITS_BIG_ENDIAN && pos >= op_precision - precision)
{
op0 = simplify_gen_unary (TRUNCATE, mode, op0, GET_MODE (op0));
if (op0)
{
pos -= op_precision - precision;
return simplify_gen_ternary (GET_CODE (op), mode, mode, op0,
XEXP (op, 1), GEN_INT (pos));
}
}
else if (!BITS_BIG_ENDIAN && precision >= len + pos)
{
op0 = simplify_gen_unary (TRUNCATE, mode, op0, GET_MODE (op0));
if (op0)
return simplify_gen_ternary (GET_CODE (op), mode, mode, op0,
XEXP (op, 1), XEXP (op, 2));
}
}
/* Recognize a word extraction from a multi-word subreg. */
if ((GET_CODE (op) == LSHIFTRT
|| GET_CODE (op) == ASHIFTRT)