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combine.c (simplify_logical): Recognize xor pattern that encodes rotation.

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* combine.c (simplify_logical): Recognize xor pattern that encodes
        rotation.

From-SVN: r29965
This commit is contained in:
Marc Espie 1999-10-14 08:18:30 +00:00 committed by Jeff Law
parent 866623d4d1
commit 0918eca064
2 changed files with 20 additions and 0 deletions
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5
gcc/ChangeLog
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@ -1,3 +1,8 @@
Thu Oct 14 02:18:19 1999 Marc Espie <espie@cvs.openbsd.org>
* combine.c (simplify_logical): Recognize xor pattern that encodes
rotation.
Wed Oct 13 23:23:45 1999 Franz Sirl <Franz.Sirl-kernel@lauterbach.com>
* rs6000.c (expand_block_move): Use INTVAL, not XINT to access

15
gcc/combine.c
View File

@ -5231,6 +5231,21 @@ simplify_logical (x, last)
&& reversible_comparison_p (op0))
return gen_rtx_combine (reverse_condition (GET_CODE (op0)),
mode, XEXP (op0, 0), XEXP (op0, 1));
/* Convert (xor (ashift A CX) (lshiftrt A CY)) where CX+CY equals the
mode size to (rotate A CX). */
if (((GET_CODE (op0) == ASHIFT && GET_CODE (op1) == LSHIFTRT)
|| (GET_CODE (op1) == ASHIFT && GET_CODE (op0) == LSHIFTRT))
&& rtx_equal_p (XEXP (op0, 0), XEXP (op1, 0))
&& GET_CODE (XEXP (op0, 1)) == CONST_INT
&& GET_CODE (XEXP (op1, 1)) == CONST_INT
&& (INTVAL (XEXP (op0, 1)) + INTVAL (XEXP (op1, 1))
== GET_MODE_BITSIZE (mode)))
return gen_rtx_ROTATE (mode, XEXP (op0, 0),
(GET_CODE (op0) == ASHIFT
? XEXP (op0, 1) : XEXP (op1, 1)));
break;
default: