rtl.h (STRING_POOL_ADDRESS_P): Rename to DEFERRED_CONSTANT_P.

	* rtl.h (STRING_POOL_ADDRESS_P): Rename to DEFERRED_CONSTANT_P.
	* varasm.c (struct varasm_status): Add deferred_constants field.
	(n_deferred_strings): Delete variable.
	(n_deferred_constants): New #define.
	(struct constant_descriptor_tree): Kill next and label fields.
	(const_hash_table, MAX_HASH_TABLE): Delete.
	(const_desc_htab): New static variable.
	(const_hash): Rename const_desc_hash, and make it fit the
	hashtab.h interface.
	(const_desc_eq): New.
	(const_hash_1, compare_constant): Const-ify arguments.
	(build_constant_desc): Set DEFERRED_CONSTANT_P on all new
	SYMBOL_REFs.  Clarify comments.  Don't set desc->label.
	(output_constant_def): Do the lookup/insert using the
	hashtab.h interface.  Don't muck with n_deferred_constants or
	DEFERRED_CONSTANT_P here.
	Always call maybe_output_constant_def_contents.
	(maybe_output_constant_def_contents): Take a pointer to the
	descriptor, not the EXP and RTL separately.  Return
	immediately if this constant is not deferred.  Defer output of
	everything, except writable string constants.  Update
	n_deferred_constants here.
	(output_constant_def_contents): Now takes just one argument,
	an rtx.  Clear DEFERRED_CONSTANT_P here.
	(mark_constant_pool): Update for rename of n_deferred_strings.
	(mark_constant): Don't clear DEFERRED_CONSTANT_P here.

	(init_varasm_status): Clear p->deferred_constants.
	(init_varasm_once): Call htab_create_ggc for const_desc_htab.

	* gcc.dg/const-elim-1.c, gcc.dg/const-elim-2.c: New testcases.

From-SVN: r66505

3 files changed, 62 insertions, 0 deletions

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 90eb31b..05b06a0 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2003-05-05  Zack Weinberg  <zack@codesourcery.com>
+
+	* gcc.dg/const-elim-1.c, gcc.dg/const-elim-2.c: New testcases.
+
 2003-05-05  Jakub Jelinek  <jakub@redhat.com>
 
 	* gcc.c-torture/execute/string-opt-18.c (main): Add 3 new tests.
diff --git a/gcc/testsuite/gcc.dg/const-elim-1.c b/gcc/testsuite/gcc.dg/const-elim-1.c
new file mode 100644
index 0000000..b704408
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/const-elim-1.c
@@ -0,0 +1,48 @@
+/* Verify that constants in memory, referenced only by dead code,
+   are not emitted to the object file.
+   FIXME: Not presently possible to apply -pedantic to code with
+   complex constants in it.  The __extension__ should shut up the
+   warning but doesn't.  (Hard to fix -- the lexer is not aware of
+   the parser's state.)  */
+
+/* { dg-do compile } */
+/* { dg-options "-O2 -std=c99" } */
+/* { dg-final { scan-assembler-not "LC" } } */
+
+#define I (__extension__ 1.0iF)
+
+struct S { int a; double b[2]; void *c; };
+
+extern void use_str(const char *);
+extern void use_S(const struct S *);
+extern void use_cplx(__complex__ double);
+
+static inline int
+returns_23(void) { return 23; }
+
+void
+test1(void)
+{
+	if (returns_23() == 23)
+		return;
+
+	use_str("waltz, nymph, for quick jigs vex bud");
+	use_S(&(const struct S){12, {3.1415, 2.1828}, 0 });
+	use_cplx(3.1415 + 2.1828*I);
+}
+
+void
+test2(void)
+{
+	const char *str = "pack my box with five dozen liquor jugs";
+	const struct S S = { 23, { 1.414, 1.618 }, 0 };
+	const __complex__ double cplx = 1.414 + 1.618*I;
+
+	if (returns_23() == 23)
+		return;
+
+	use_str(str);
+	use_S(&S);
+	use_cplx(cplx);
+}
+
diff --git a/gcc/testsuite/gcc.dg/const-elim-2.c b/gcc/testsuite/gcc.dg/const-elim-2.c
new file mode 100644
index 0000000..ce55ba1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/const-elim-2.c
@@ -0,0 +1,10 @@
+/* The string constant in this test case should be emitted exactly once.  */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { scan-assembler-times "hi there" 1 } } */
+
+static inline int returns_23() { return 23; }
+
+const char *test1(void) { if (returns_23()) return 0; return "hi there"; }
+const char *test2(void) { return "hi there"; }
+const char *test3(void) { return "hi there"; }