diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.c-torture/execute/20071011-1.c | 19 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/forwprop-3.c | 18 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-9.c | 2 | ||||
| -rw-r--r-- | gcc/tree-ssa-forwprop.c | 32 |
6 files changed, 76 insertions, 9 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 28590a6c41b..9abace31683 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2007-10-12 Richard Guenther <rguenther@suse.de> + + PR middle-end/26198 + * tree-ssa-forwprop.c (can_propagate_from): Do not propagate from + a rhs with side-effects or which is a load. + (forward_propagate_into_cond): Also try combining both operands. + 2007-10-12 Uros Bizjak <ubizjak@gmail.com> PR tree-optimization/33742 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index cacf0a9ed7d..97d93ea5ef1 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,10 @@ +2007-10-12 Richard Guenther <rguenther@suse.de> + + PR middle-end/26198 + * gcc.dg/tree-ssa/forwprop-3.c: New testcase. + * gcc.c-torture/execute/20071011-1.c: Likewise. + * gcc.dg/tree-ssa/ssa-pre-9.c: Adjust. + 2007-10-12 Uros Bizjak <ubizjak@gmail.com> PR tree-optimization/33742 diff --git a/gcc/testsuite/gcc.c-torture/execute/20071011-1.c b/gcc/testsuite/gcc.c-torture/execute/20071011-1.c new file mode 100644 index 00000000000..631658540b3 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/20071011-1.c @@ -0,0 +1,19 @@ +extern void abort(void); +void foo(int *p) +{ + int x; + int y; + x = *p; + *p = 0; + y = *p; + if (x != y) + return; + abort (); +} + +int main() +{ + int a = 1; + foo(&a); + return 0; +} diff --git a/gcc/testsuite/gcc.dg/tree-ssa/forwprop-3.c b/gcc/testsuite/gcc.dg/tree-ssa/forwprop-3.c new file mode 100644 index 00000000000..0d26b8d9cf3 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/forwprop-3.c @@ -0,0 +1,18 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-forwprop1" } */ + +struct bar { + int a[2]; +}; + +int foo(struct bar *x) +{ + int *p = &x->a[0]; + int *q = &x->a[1]; + if (p < q) + return 1; + return 0; +} + +/* { dg-final { scan-tree-dump "Replaced .p_. < q_.. with .1." "forwprop1" } } */ +/* { dg-final { cleanup-tree-dump "forwprop1" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-9.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-9.c index 32e37b99703..30d968b7c53 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-9.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-9.c @@ -9,5 +9,5 @@ foo (unsigned long a) return 1; return 0; } -/* { dg-final { scan-tree-dump-times "Eliminated: 1" 1 "fre"} } */ +/* { dg-final { scan-tree-dump-times "return 0;" 0 "fre"} } */ /* { dg-final { cleanup-tree-dump "fre" } } */ diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c index 3b72b6c44af..b92a9f13f48 100644 --- a/gcc/tree-ssa-forwprop.c +++ b/gcc/tree-ssa-forwprop.c @@ -237,6 +237,14 @@ can_propagate_from (tree def_stmt) { tree rhs = GIMPLE_STMT_OPERAND (def_stmt, 1); + /* If the rhs has side-effects we cannot propagate from it. */ + if (TREE_SIDE_EFFECTS (rhs)) + return false; + + /* If the rhs is a load we cannot propagate from it. */ + if (REFERENCE_CLASS_P (rhs)) + return false; + /* We cannot propagate ssa names that occur in abnormal phi nodes. */ switch (TREE_CODE_LENGTH (TREE_CODE (rhs))) { @@ -351,7 +359,7 @@ forward_propagate_into_cond (tree cond_expr, tree stmt) do { tree tmp = NULL_TREE; tree cond = COND_EXPR_COND (cond_expr); - tree name, def_stmt, rhs; + tree name, def_stmt, rhs0 = NULL_TREE, rhs1 = NULL_TREE; bool single_use_p; /* We can do tree combining on SSA_NAME and comparison expressions. */ @@ -366,9 +374,9 @@ forward_propagate_into_cond (tree cond_expr, tree stmt) && can_propagate_from (def_stmt)) { tree op1 = TREE_OPERAND (cond, 1); - rhs = GIMPLE_STMT_OPERAND (def_stmt, 1); + rhs0 = GIMPLE_STMT_OPERAND (def_stmt, 1); tmp = combine_cond_expr_cond (TREE_CODE (cond), boolean_type_node, - fold_convert (TREE_TYPE (op1), rhs), + fold_convert (TREE_TYPE (op1), rhs0), op1, !single_use_p); } /* If that wasn't successful, try the second operand. */ @@ -382,12 +390,20 @@ forward_propagate_into_cond (tree cond_expr, tree stmt) || !can_propagate_from (def_stmt)) return did_something; - rhs = GIMPLE_STMT_OPERAND (def_stmt, 1); + rhs1 = GIMPLE_STMT_OPERAND (def_stmt, 1); tmp = combine_cond_expr_cond (TREE_CODE (cond), boolean_type_node, op0, - fold_convert (TREE_TYPE (op0), rhs), + fold_convert (TREE_TYPE (op0), rhs1), !single_use_p); } + /* If that wasn't successful either, try both operands. */ + if (tmp == NULL_TREE + && rhs0 != NULL_TREE + && rhs1 != NULL_TREE) + tmp = combine_cond_expr_cond (TREE_CODE (cond), boolean_type_node, + rhs0, + fold_convert (TREE_TYPE (rhs0), rhs1), + !single_use_p); } else if (TREE_CODE (cond) == SSA_NAME) { @@ -397,9 +413,9 @@ forward_propagate_into_cond (tree cond_expr, tree stmt) || !can_propagate_from (def_stmt)) return did_something; - rhs = GIMPLE_STMT_OPERAND (def_stmt, 1); - tmp = combine_cond_expr_cond (NE_EXPR, boolean_type_node, rhs, - build_int_cst (TREE_TYPE (rhs), 0), + rhs0 = GIMPLE_STMT_OPERAND (def_stmt, 1); + tmp = combine_cond_expr_cond (NE_EXPR, boolean_type_node, rhs0, + build_int_cst (TREE_TYPE (rhs0), 0), false); } |