diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/pr21294.c | 23 | ||||
| -rw-r--r-- | gcc/tree-vrp.c | 31 |
4 files changed, 64 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index d3d7f07..20bf784 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2005-05-02 Kazu Hirata <kazu@cs.umass.edu> + + PR tree-optimization/21294 + * tree-vrp.c (vrp_expr_computes_nonzero): New. + (extract_range_from_expr): Call vrp_expr_computes_nonzero. + 2005-05-02 Janis Johnson <janis187@us.ibm.com> PR 19985 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 7c5caab..46c9e1d 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2005-05-02 Kazu Hirata <kazu@cs.umass.edu> + + PR tree-optimization/21294 + * gcc.dg/tree-ssa/pr21294.c: New. + 2005-05-02 Paolo Bonzini <bonzini@gnu.org> * gcc.dg/altivec-3.c (vec_store): Do not use the old diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr21294.c b/gcc/testsuite/gcc.dg/tree-ssa/pr21294.c new file mode 100644 index 0000000..dc90dbd --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr21294.c @@ -0,0 +1,23 @@ +/* PR tree-optimization/21294 + VRP did not notice that an address of the form &p->i is nonnull + when p is known to be nonnull. In this testcase, noticing that + allows us to eliminate the second "if" statement. */ + +/* { dg-do compile } */ +/* { dg-options "-O2 -fno-tree-dominator-opts -fdump-tree-vrp-details" } */ + +struct f { + int i; +}; + +int +foo (struct f *p) +{ + if (p != 0) + if (&p->i != 0) + return 123; + return 0; +} + +/* { dg-final { scan-tree-dump-times "Folding predicate" 1 "vrp"} } */ +/* { dg-final { cleanup-tree-dump "vrp" } } */ diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index 0fe5c7b..e6cb017 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -717,6 +717,35 @@ extract_range_from_binary_expr (value_range *vr, tree expr) } +/* Like expr_computes_nonzero, but this function uses value ranges + obtained so far. */ + +static bool +vrp_expr_computes_nonzero (tree expr) +{ + if (expr_computes_nonzero (expr)) + return true; + + /* If we have an expression of the form &X->a, then the expression + is nonnull if X is nonnull. */ + if (TREE_CODE (expr) == ADDR_EXPR) + { + tree base = get_base_address (TREE_OPERAND (expr, 0)); + + if (base != NULL_TREE + && TREE_CODE (base) == INDIRECT_REF + && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) + { + value_range *vr = get_value_range (TREE_OPERAND (base, 0)); + if (range_is_nonnull (vr)) + return true; + } + } + + return false; +} + + /* Extract range information from a unary expression EXPR based on the range of its operand and the expression code. */ @@ -833,7 +862,7 @@ extract_range_from_expr (value_range *vr, tree expr) extract_range_from_binary_expr (vr, expr); else if (TREE_CODE_CLASS (code) == tcc_unary) extract_range_from_unary_expr (vr, expr); - else if (expr_computes_nonzero (expr)) + else if (vrp_expr_computes_nonzero (expr)) set_value_range_to_nonnull (vr, TREE_TYPE (expr)); else if (TREE_CODE (expr) == INTEGER_CST) set_value_range (vr, VR_RANGE, expr, expr); |