diff options
| -rw-r--r-- | gcc/match.pd | 21 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/pr107699.c | 15 |
2 files changed, 28 insertions, 8 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index f48cbd9..127cef9 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -2260,6 +2260,19 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) && (CONSTANT_CLASS_P (@1) || (single_use (@2) && single_use (@3)))) (op @1 { build_zero_cst (TREE_TYPE (@1)); })))) +/* (&a + b) !=/== (&a[1] + c) -> (&a[0] - &a[1]) + b !=/== c */ +(for neeq (ne eq) + (simplify + (neeq:c ADDR_EXPR@0 (pointer_plus ADDR_EXPR@2 @3)) + (with { poly_int64 diff; tree inner_type = TREE_TYPE (@3);} + (if (ptr_difference_const (@0, @2, &diff)) + (neeq { build_int_cst_type (inner_type, diff); } @3)))) + (simplify + (neeq (pointer_plus ADDR_EXPR@0 @1) (pointer_plus ADDR_EXPR@2 @3)) + (with { poly_int64 diff; tree inner_type = TREE_TYPE (@1);} + (if (ptr_difference_const (@0, @2, &diff)) + (neeq (plus { build_int_cst_type (inner_type, diff); } @1) @3))))) + /* X - Y < X is the same as Y > 0 when there is no overflow. For equality, this is also true with wrapping overflow. */ (for op (simple_comparison) @@ -2439,14 +2452,6 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (if (ptr_difference_const (@0, @2, &diff)) (plus { build_int_cst_type (type, diff); } (convert (minus @1 @3)))))) -/* (&a+b) !=/== (&a[1] + c) -> sizeof(a[0]) + b !=/== c */ -(for neeq (ne eq) - (simplify - (neeq (pointer_plus ADDR_EXPR@0 @1) (pointer_plus ADDR_EXPR@2 @3)) - (with { poly_int64 diff; tree inner_type = TREE_TYPE (@1);} - (if (ptr_difference_const (@0, @2, &diff)) - (neeq (plus { build_int_cst_type (inner_type, diff); } @1) @3))))) - /* Canonicalize (T *)(ptr - ptr-cst) to &MEM[ptr + -ptr-cst]. */ (simplify (convert (pointer_diff @0 INTEGER_CST@1)) diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr107699.c b/gcc/testsuite/gcc.dg/tree-ssa/pr107699.c new file mode 100644 index 0000000..4bf864d --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr107699.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-forwprop1" } */ + +struct { int data[16]; } x; + +int foo (int n) +{ + int *p = x.data + n; + /* Should simplify this to n * 4 != 0. */ + if ((void *)&x != (void *)p) + return 1; + return 0; +} + +/* { dg-final { scan-tree-dump " != 0" "forwprop1" } } */ |