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[Committed] PR middle-end/23670: Optimize (X&Y)|Y as (X,Y)
- From: Roger Sayle <roger at eyesopen dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Tue, 14 Feb 2006 14:13:31 -0700 (MST)
- Subject: [Committed] PR middle-end/23670: Optimize (X&Y)|Y as (X,Y)
The following patch is the generic solution to PR middle-end/23670
that I'd previously promised Andrew Pinski.
This patch has been tested on i686-pc-linux-gnu, with a full "make
bootstrap", all default languages including Ada, and regression
checked with a top-level "make -k check" with no new failures.
Committed to mainline as revision 110997.
2006-02-14 Roger Sayle <roger@eyesopen.com>
PR middle-end/23670
* fold-const.c (fold_binary) <BIT_IOR_EXPR>: Optimize (X&Y)|Y into
(X,Y) and the corresponding symmetry related transformations.
(fold_binary) <BIT_AND_EXPR>: Likewise, optimize (X|Y)&Y into
(X,Y) and its symmetry related transformations.
* gcc.dg/tree-ssa/andor-2.c: New test case.
Index: fold-const.c
===================================================================
*** fold-const.c (revision 110920)
--- fold-const.c (working copy)
*************** fold_binary (enum tree_code code, tree t
*** 8161,8166 ****
--- 8161,8186 ----
arg1);
}
+ /* (X & Y) | Y is (X, Y). */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
+ return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
+ /* (X & Y) | X is (Y, X). */
+ if (TREE_CODE (arg0) == BIT_AND_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
+ && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
+ return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
+ /* X | (X & Y) is (Y, X). */
+ if (TREE_CODE (arg1) == BIT_AND_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
+ && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
+ return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
+ /* X | (Y & X) is (Y, X). */
+ if (TREE_CODE (arg1) == BIT_AND_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
+ && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
+ return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
+
t1 = distribute_bit_expr (code, type, arg0, arg1);
if (t1 != NULL_TREE)
return t1;
*************** fold_binary (enum tree_code code, tree t
*** 8313,8318 ****
--- 8333,8358 ----
fold_build2 (BIT_AND_EXPR, type,
TREE_OPERAND (arg0, 1), arg1));
+ /* (X | Y) & Y is (X, Y). */
+ if (TREE_CODE (arg0) == BIT_IOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
+ return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
+ /* (X | Y) & X is (Y, X). */
+ if (TREE_CODE (arg0) == BIT_IOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
+ && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
+ return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
+ /* X & (X | Y) is (Y, X). */
+ if (TREE_CODE (arg1) == BIT_IOR_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
+ && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
+ return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
+ /* X & (Y | X) is (Y, X). */
+ if (TREE_CODE (arg1) == BIT_IOR_EXPR
+ && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
+ && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
+ return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
+
t1 = distribute_bit_expr (code, type, arg0, arg1);
if (t1 != NULL_TREE)
return t1;
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-original" } */
int test1(int a, int b)
{
return (a & b) | b;
}
int test2(int c, int d)
{
return (c & d) | c;
}
int test3(int e, int f)
{
return e | (e & f);
}
int test4(int g, int h)
{
return g | (h & g);
}
int test5(int i, int j)
{
return (i | j) & j;
}
int test6(int k, int l)
{
return (k | l) & k;
}
int test7(int m, int n)
{
return m & (m | n);
}
int test8(int o, int p)
{
return o & (p | o);
}
/* { dg-final { scan-tree-dump-times "return b;" 1 "original" } } */
/* { dg-final { scan-tree-dump-times "return c;" 1 "original" } } */
/* { dg-final { scan-tree-dump-times "return e;" 1 "original" } } */
/* { dg-final { scan-tree-dump-times "return g;" 1 "original" } } */
/* { dg-final { scan-tree-dump-times "return j;" 1 "original" } } */
/* { dg-final { scan-tree-dump-times "return k;" 1 "original" } } */
/* { dg-final { scan-tree-dump-times "return m;" 1 "original" } } */
/* { dg-final { scan-tree-dump-times "return o;" 1 "original" } } */
/* { dg-final { cleanup-tree-dump "original" } } */
Roger
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