pa.md (call, call_value): Always save the PIC register before a call.

	* pa.md (call, call_value): Always save the PIC register before
	a call.

From-SVN: r8836

diff --git a/gcc/config/pa/pa.md b/gcc/config/pa/pa.md
index 7c2be01c120c357895cfc22ce3a2cbccba5c01f6..62bd4e2072f767b60308f1df6462b86066e5575f 100644 (file)
--- a/gcc/config/pa/pa.md
+++ b/gcc/config/pa/pa.md
@@ -3426,13 +3426,19 @@
       use_reg (&CALL_INSN_FUNCTION_USAGE (call_insn), pic_offset_table_rtx);
 
       if (!hppa_save_pic_table_rtx)
-       {
-         hppa_save_pic_table_rtx = gen_reg_rtx (Pmode);
-         emit_insn_before (gen_rtx (SET, VOIDmode,
-                                   hppa_save_pic_table_rtx,
-                                   pic_offset_table_rtx),
-                          call_insn);
-       }
+       hppa_save_pic_table_rtx = gen_reg_rtx (Pmode);
+
+      /* We must save and restore the PIC register around every call
+        since we don't have flow information to determine if this save
+        is redundant with a previous save.  The old code assumed once
+        the register was saved it never needs to be saved again, but
+        the save could have been on a path which doesn't always
+        execute; a call site physically later in the program would
+        then attempt a restore from an uninitialized register!  */
+      emit_insn_before (gen_rtx (SET, VOIDmode,
+                                hppa_save_pic_table_rtx,
+                                pic_offset_table_rtx),
+                       call_insn);
 
       emit_insn (gen_rtx (SET, VOIDmode, pic_offset_table_rtx,
                          hppa_save_pic_table_rtx));
@@ -3522,13 +3528,19 @@
       use_reg (&CALL_INSN_FUNCTION_USAGE (call_insn), pic_offset_table_rtx);
 
       if (!hppa_save_pic_table_rtx)
-       {
-         hppa_save_pic_table_rtx = gen_reg_rtx (Pmode);
-         emit_insn_before (gen_rtx (SET, VOIDmode,
-                                   hppa_save_pic_table_rtx,
-                                   pic_offset_table_rtx),
-                          call_insn);
-       }
+       hppa_save_pic_table_rtx = gen_reg_rtx (Pmode);
+
+      /* We must save and restore the PIC register around every call
+        since we don't have flow information to determine if this save
+        is redundant with a previous save.  The old code assumed once
+        the register was saved it never needs to be saved again, but
+        the save could have been on a path which doesn't always
+        execute; a call site physically later in the program would
+        then attempt a restore from an uninitialized register!  */
+      emit_insn_before (gen_rtx (SET, VOIDmode,
+                                hppa_save_pic_table_rtx,
+                                pic_offset_table_rtx),
+                       call_insn);
 
       emit_insn (gen_rtx (SET, VOIDmode, pic_offset_table_rtx,
                          hppa_save_pic_table_rtx));