Hi! We already have x - ((x - y) & -(z < w)) and x + ((y - x) & -(z < w)) simplifications, this one adds x ^ ((x ^ y) & -(z < w)) (not merged using for because of the :c that can be present on bit_xor and can't on minus).
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2020-05-08 Jakub Jelinek <ja...@redhat.com> PR tree-optimization/94786 * match.pd (A ^ ((A ^ B) & -(C cmp D)) -> (C cmp D) ? B : A): New simplification. * gcc.dg/tree-ssa/pr94786.c: New test. --- gcc/match.pd.jj 2020-05-07 16:37:22.377391704 +0200 +++ gcc/match.pd 2020-05-07 18:28:19.037182220 +0200 @@ -2791,6 +2791,18 @@ (define_operator_list COND_TERNARY && (TYPE_PRECISION (TREE_TYPE (@4)) >= TYPE_PRECISION (type) || !TYPE_UNSIGNED (TREE_TYPE (@4))) && (GIMPLE || !TREE_SIDE_EFFECTS (@1))) + (cond (cmp @2 @3) @1 @0))) + /* Similarly with ^ instead of - though in that case with :c. */ + (simplify + (bit_xor:c @0 (bit_and:c (bit_xor:c @0 @1) + (convert? (negate@4 (convert? (cmp@5 @2 @3)))))) + (if (INTEGRAL_TYPE_P (type) + && INTEGRAL_TYPE_P (TREE_TYPE (@4)) + && TREE_CODE (TREE_TYPE (@4)) != BOOLEAN_TYPE + && INTEGRAL_TYPE_P (TREE_TYPE (@5)) + && (TYPE_PRECISION (TREE_TYPE (@4)) >= TYPE_PRECISION (type) + || !TYPE_UNSIGNED (TREE_TYPE (@4))) + && (GIMPLE || !TREE_SIDE_EFFECTS (@1))) (cond (cmp @2 @3) @1 @0)))) /* Simplifications of shift and rotates. */ --- gcc/testsuite/gcc.dg/tree-ssa/pr94786.c.jj 2020-05-07 18:37:29.243891187 +0200 +++ gcc/testsuite/gcc.dg/tree-ssa/pr94786.c 2020-05-07 18:33:23.001601189 +0200 @@ -0,0 +1,66 @@ +/* PR tree-optimization/94786 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ +/* { dg-final { scan-tree-dump-times "MIN_EXPR <" 4 "optimized" } } */ +/* { dg-final { scan-tree-dump-times "MAX_EXPR <" 4 "optimized" } } */ + +static inline unsigned +umax1 (unsigned a, unsigned b) +{ + return a ^ ((a ^ b) & -(a < b)); +} + +static inline unsigned +umin1 (unsigned a, unsigned b) +{ + return a ^ ((a ^ b) & -(a > b)); +} + +static inline int +smax1 (int a, int b) +{ + return a ^ ((a ^ b) & -(a < b)); +} + +static inline int +smin1 (int a, int b) +{ + return a ^ ((a ^ b) & -(a > b)); +} + +static inline unsigned long long +umax2 (unsigned long long a, unsigned long long b) +{ + return a ^ ((a ^ b) & -(a <= b)); +} + +static inline unsigned long long +umin2 (unsigned long long a, unsigned long long b) +{ + return a ^ ((a ^ b) & -(a >= b)); +} + +static inline long long +smax2 (long long a, long long b) +{ + return a ^ ((a ^ b) & -(a <= b)); +} + +static inline long long +smin2 (long long a, long long b) +{ + return a ^ ((a ^ b) & -(a >= b)); +} + +void +test (unsigned *x, int *y, unsigned long long *z, long long *w) +{ + x[2] = umax1 (x[0], x[1]); + x[5] = umin1 (x[2], x[3]); + y[2] = smax1 (y[0], y[1]); + y[5] = smin1 (y[2], y[3]); + z[2] = umax2 (z[0], z[1]); + z[5] = umin2 (z[2], z[3]); + w[2] = smax2 (w[0], w[1]); + w[5] = smin2 (w[2], w[3]); +} Jakub