From: Jeff Law <law@gcc.gnu.org>
Date: Sat, 28 Jan 1995 18:55:00 +0000 (-0700)
Subject: pa.md (call, call_value): Always save the PIC register before a call.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=da6f15cdef9251ed945e2435e12aa3713cf0d808;p=gcc.git

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 7c2be01c120..62bd4e2072f 100644
--- 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));