re PR tree-optimization/20100 (LIM is pulling out a pure function even though there is something which can modify global memory)

	PR tree-optimization/20100
	PR tree-optimization/20115
	* tree-optimize.c (init_tree_optimization_passes): Remove
	pass_maybe_create_global_var.
	* tree-pass.h (pass_maybe_create_global_var): Remove.
	* tree-ssa-alias.c (aliases_computed_p): Declare.
	(struct alias_info): Add field NUM_PURE_CONST_CALLS_FOUND.
	(count_calls_and_maybe_create_global_var): Remove.
	(pass_maybe_create_global_var): Remove.
	(init_alias_info): Do not declare aliases_computed_p.
	(maybe_create_global_var): If the function contains no
	call-clobbered variables and a mix of pure/const and regular
	function calls, create .GLOBAL_VAR.
	Mark all call-clobbered variables for renaming.
	(merge_pointed_to_info): Update comment.
	(add_pointed_to_var): Likewise.
	(is_escape_site): Likewise.
	Accept struct alias_info * instead of size_t *.
	Update all users.
	Update AI->NUM_CALLS_FOUND and AI->NUM_PURE_CONST_CALLS_FOUND
	as necessary.
	* tree-ssa-operands.c (get_call_expr_operands): If
	ALIASES_COMPUTED_P is false, do not add call-clobbering
	operands.
	* tree-ssa.c (init_tree_ssa): Set ALIASES_COMPUTED_P to false.
	(delete_tree_ssa): Likewise.

testsuite/ChangeLog

	PR tree-optimization/20100
	PR tree-optimization/20115
	* gcc.dg/pr20115.c: New test.
	* gcc.dg/pr20115-1.c: New test.
	* gcc.dg/pr20100.c: New test.
	* gcc.dg/tree-ssa/20040517-1.c: Expect virtual operands for
	call-clobbered variables after alias1.

From-SVN: r95437

1 files changed, 28 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/pr20115.c b/gcc/testsuite/gcc.dg/pr20115.c
new file mode 100644
index 0000000..cea4b48
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr20115.c
@@ -0,0 +1,28 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+int func_pure (void);
+void func_other (int);
+int global_int;
+int func_pure (void) { return global_int; }
+void func_other (int a)
+{
+  global_int = a + 1;
+}
+int f(void)
+{
+  int a;
+  a = func_pure();
+  func_other (a);
+  a = func_pure (); // We were removing this function call
+  return a;
+}
+void abort (void);
+
+int main(void)
+{
+  global_int = 10;
+  if (f() != 11)
+    abort ();
+  return 0;
+}