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Optimize two patterns with three xors

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gcc/
	PR tree-optimization/96671
	* match.pd (three xor patterns): New patterns.
This commit is contained in:
Eugene Rozenfeld 2020-11-18 14:29:49 -05:00 committed by Jeff Law
parent 6fae7eda96
commit f44e609162
1 changed files with 10 additions and 0 deletions
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gcc/match.pd
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@ -901,6 +901,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(bit_not (bit_ior:cs (bit_not @0) @1))
(bit_and @0 (bit_not @1)))
/* (a ^ b) & ((b ^ c) ^ a) --> (a ^ b) & ~c */
(simplify
(bit_and:c (bit_xor:c@3 @0 @1) (bit_xor:cs (bit_xor:cs @1 @2) @0))
(bit_and @3 (bit_not @2)))
/* (a ^ b) | ((b ^ c) ^ a) --> (a ^ b) | c */
(simplify
(bit_ior:c (bit_xor:c@3 @0 @1) (bit_xor:c (bit_xor:c @1 @2) @0))
(bit_ior @3 @2))
/* Simplify (~X & Y) to X ^ Y if we know that (X & ~Y) is 0. */
#if GIMPLE
(simplify