This adds BIT_XOR_EXPR support to propagation, similar to how we
have BIT_IOR_EXPR and BIT_AND_EXPR support (but without the
adjustment for constant vr0/1 min/max which I think we cannot do
for XOR).
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2011-08-05 Richard Guenther <rguent...@suse.de>
PR tree-optimization/49984
* tree-vrp.c (extract_range_from_binary_expr_1): Handle BIT_XOR_EXPR.
* gcc.dg/tree-ssa/vrp59.c: New testcase.
Index: gcc/tree-vrp.c
===================================================================
*** gcc/tree-vrp.c (revision 177423)
--- gcc/tree-vrp.c (working copy)
*************** extract_range_from_binary_expr_1 (value_
*** 2214,2220 ****
&& code != MIN_EXPR
&& code != MAX_EXPR
&& code != BIT_AND_EXPR
! && code != BIT_IOR_EXPR)
{
set_value_range_to_varying (vr);
return;
--- 2214,2221 ----
&& code != MIN_EXPR
&& code != MAX_EXPR
&& code != BIT_AND_EXPR
! && code != BIT_IOR_EXPR
! && code != BIT_XOR_EXPR)
{
set_value_range_to_varying (vr);
return;
*************** extract_range_from_binary_expr_1 (value_
*** 2635,2641 ****
min = vrp_int_const_binop (code, vr0.min, vr1.max);
max = vrp_int_const_binop (code, vr0.max, vr1.min);
}
! else if (code == BIT_AND_EXPR || code == BIT_IOR_EXPR)
{
bool int_cst_range0, int_cst_range1;
double_int may_be_nonzero0, may_be_nonzero1;
--- 2636,2642 ----
min = vrp_int_const_binop (code, vr0.min, vr1.max);
max = vrp_int_const_binop (code, vr0.max, vr1.min);
}
! else if (code == BIT_AND_EXPR || code == BIT_IOR_EXPR || code ==
BIT_XOR_EXPR)
{
bool int_cst_range0, int_cst_range1;
double_int may_be_nonzero0, may_be_nonzero1;
*************** extract_range_from_binary_expr_1 (value_
*** 2694,2699 ****
--- 2695,2729 ----
if (int_cst_range1)
min = vrp_int_const_binop (MAX_EXPR, min, vr1.min);
}
+ else if (code == BIT_XOR_EXPR)
+ {
+ double_int result_zero_bits, result_one_bits;
+ result_zero_bits
+ = double_int_ior (double_int_and (must_be_nonzero0,
+ must_be_nonzero1),
+ double_int_not
+ (double_int_ior (may_be_nonzero0,
+ may_be_nonzero1)));
+ result_one_bits
+ = double_int_ior (double_int_and
+ (must_be_nonzero0,
+ double_int_not (may_be_nonzero1)),
+ double_int_and
+ (must_be_nonzero1,
+ double_int_not (may_be_nonzero0)));
+ max = double_int_to_tree (expr_type,
+ double_int_not (result_zero_bits));
+ min = double_int_to_tree (expr_type, result_one_bits);
+ /* Return a [min, max] range if we know the
+ result range is either positive or negative. */
+ if (tree_int_cst_sgn (max) >= 0)
+ /* The range is bound by a lower value of 0. */;
+ else if (tree_int_cst_sgn (min) < 0)
+ /* The range is bound by an upper value of -1. */;
+ else
+ /* We don't know whether the sign bit is set or not. */
+ max = min = NULL_TREE;
+ }
else
{
set_value_range_to_varying (vr);
Index: gcc/testsuite/gcc.dg/tree-ssa/vrp59.c
===================================================================
*** gcc/testsuite/gcc.dg/tree-ssa/vrp59.c (revision 0)
--- gcc/testsuite/gcc.dg/tree-ssa/vrp59.c (revision 0)
***************
*** 0 ****
--- 1,35 ----
+ /* { dg-do compile } */
+ /* { dg-options "-O2 -fno-tree-ccp -fdump-tree-vrp1" } */
+
+ int f(int x)
+ {
+ if (x >= 0 && x <= 3)
+ {
+ x = x ^ 3;
+ x = x & 3;
+ }
+ return x;
+ }
+
+ int g(int x)
+ {
+ if (x >= 0 && x <= 3)
+ {
+ x = x ^ 2;
+ x = x & 3;
+ }
+ return x;
+ }
+
+ int h(int x)
+ {
+ if (x >= 0 && x <= 3)
+ {
+ x = x ^ 1;
+ x = x & 3;
+ }
+ return x;
+ }
+
+ /* { dg-final { scan-tree-dump-not " & 3;" "vrp1" } } */
+ /* { dg-final { cleanup-tree-dump "vrp1" } } */
