PR c/9530

	* config/i386/i386.c (ix86_function_ok_for_sibcall): Forbid sibcalls
	from functions that return a float to functions that don't.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@62480 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ea7c3c5..921d0d6 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2003-02-06  Eric Botcazou <ebotcazou@libertysurf.fr>
+            Richard Henderson <rth@redhat.com>
+
+       PR c/9530
+       * config/i386/i386.c (ix86_function_ok_for_sibcall): Forbid sibcalls
+       from functions that return a float to functions that don't.
+
 Thu Feb  6 00:18:38 CET 2003  Jan Hubicka  <jh@suse.cz>
 
        * i386.c (x86_inter_unit_moves): New variable.

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 2c71e1e..23f2494 100644 (file)
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -1482,11 +1482,9 @@ const struct attribute_spec ix86_attribute_table[] =
   { NULL,        0, 0, false, false, false, NULL }
 };
 
-/* If PIC, we cannot make sibling calls to global functions
-   because the PLT requires %ebx live.
-   If we are returning floats on the register stack, we cannot make
-   sibling calls to functions that return floats.  (The stack adjust
-   instruction will wind up after the sibcall jump, and not be executed.)  */
+/* Decide whether we can make a sibling call to a function.  DECL is the
+   declaration of the function being targeted by the call and EXP is the
+   CALL_EXPR representing the call.  */
 
 static bool
 ix86_function_ok_for_sibcall (decl, exp)
@@ -1501,10 +1499,11 @@ ix86_function_ok_for_sibcall (decl, exp)
 
   /* If we are returning floats on the 80387 register stack, we cannot
      make a sibcall from a function that doesn't return a float to a
-     function that does; the necessary stack adjustment will not be
-     executed.  */
+     function that does or, conversely, from a function that does return
+     a float to a function that doesn't; the necessary stack adjustment
+     would not be executed.  */
   if (STACK_REG_P (ix86_function_value (TREE_TYPE (exp)))
-      && ! STACK_REG_P (ix86_function_value (TREE_TYPE (DECL_RESULT (cfun->decl)))))
+      != STACK_REG_P (ix86_function_value (TREE_TYPE (DECL_RESULT (cfun->decl)))))
     return false;
 
   /* If this call is indirect, we'll need to be able to use a call-clobbered

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0d39f62..a4f6ad1 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2003-02-06  Eric Botcazou <ebotcazou@libertysurf.fr>
+
+       * gcc.c-torture/compile/20030206-1.c: New test.
+
 2003-02-05  Roger Sayle  <roger@eyesopen.com>
 
        * gcc.c-torture/compile/921206-1.c: Rename undeclared function from

diff --git a/gcc/testsuite/gcc.c-torture/compile/20030206-1.c b/gcc/testsuite/gcc.c-torture/compile/20030206-1.c
new file mode 100644 (file)
index 0000000..1e0d544
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/20030206-1.c
@@ -0,0 +1,14 @@
+/* PR c/9530 */
+/* Contributed by Volker Reichelt. */
+
+/* Verify that the call to 'foo' is not turned
+   into a sibling call.  */
+
+void foo(float d);
+
+float bar(float d);
+
+float baz(float d)
+{
+  foo(bar(d));
+}