re PR target/15832 (ICE in move_for_stack_reg, at reg-stack.c:1120)

2004-09-03  Vladimir Makarov  <vmakarov@redhat.com>

	PR target/15832
	* global.c (modify_reg_pav): New function.
	(make_accurate_live_analysis): Call the new function.  Move pavin
	modification by earlyclobber set into the new function.

From-SVN: r87035

2 files changed, 64 insertions, 6 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index da4164b..98cd604 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2004-09-03  Vladimir Makarov  <vmakarov@redhat.com>
+
+	PR target/15832
+	* global.c (modify_reg_pav): New function.
+	(make_accurate_live_analysis): Call the new function.  Move pavin
+	modification by earlyclobber set into the new function.
+
 2004-09-03  Andreas Schwab  <schwab@suse.de>
 
 	* config/m68k/m68k.c (output_andsi3): Use -1 instead of
diff --git a/gcc/global.c b/gcc/global.c
index ab50844..9964d72 100644
--- a/gcc/global.c
+++ b/gcc/global.c
@@ -319,6 +319,7 @@ static void set_up_bb_rts_numbers (void);
 static int rpost_cmp (const void *, const void *);
 static bool modify_bb_reg_pav (basic_block, basic_block, bool);
 static void calculate_reg_pav (void);
+static void modify_reg_pav (void);
 static void make_accurate_live_analysis (void);
 
 
@@ -2360,6 +2361,61 @@ calculate_reg_pav (void)
   sbitmap_free (wset);
 }
 
+/* The function modifies partial availability information for two
+   special cases to prevent incorrect work of the subsequent passes
+   with the accurate live information based on the partial
+   availability.  */
+
+static void
+modify_reg_pav (void)
+{
+  basic_block bb;
+  struct bb_info *bb_info;
+#ifdef STACK_REGS
+  int i;
+  HARD_REG_SET zero, stack_hard_regs, used;
+  bitmap stack_regs;
+
+  CLEAR_HARD_REG_SET (zero);
+  CLEAR_HARD_REG_SET (stack_hard_regs);
+  for (i = FIRST_STACK_REG; i <= LAST_STACK_REG; i++)
+    SET_HARD_REG_BIT(stack_hard_regs, i);
+  stack_regs = BITMAP_XMALLOC ();
+  for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
+    {
+      COPY_HARD_REG_SET (used, reg_class_contents[reg_preferred_class (i)]);
+      IOR_HARD_REG_SET (used, reg_class_contents[reg_alternate_class (i)]);
+      AND_HARD_REG_SET (used, stack_hard_regs);
+      GO_IF_HARD_REG_EQUAL(used, zero, skip);
+      bitmap_set_bit (stack_regs, i);
+    skip:
+      ;
+    }
+#endif
+  FOR_EACH_BB (bb)
+    {
+      bb_info = BB_INFO (bb);
+      
+      /* Reload can assign the same hard register to uninitialized
+	 pseudo-register and early clobbered pseudo-register in an
+	 insn if the pseudo-register is used first time in given BB
+	 and not lived at the BB start.  To prevent this we don't
+	 change life information for such pseudo-registers.  */
+      bitmap_a_or_b (bb_info->pavin, bb_info->pavin, bb_info->earlyclobber);
+#ifdef STACK_REGS
+      /* We can not use the same stack register for uninitialized
+	 pseudo-register and another living pseudo-register because if the
+	 uninitialized pseudo-register dies, subsequent pass reg-stack
+	 will be confused (it will believe that the other register
+	 dies).  */
+      bitmap_a_or_b (bb_info->pavin, bb_info->pavin, stack_regs);
+#endif
+    }
+#ifdef STACK_REGS
+  BITMAP_XFREE (stack_regs);
+#endif
+}
+
 /* The following function makes live information more accurate by
    modifying global_live_at_start and global_live_at_end of basic
    blocks.  After the function call a register lives at a program
@@ -2379,16 +2435,11 @@ make_accurate_live_analysis (void)
   calculate_local_reg_bb_info ();
   set_up_bb_rts_numbers ();
   calculate_reg_pav ();
+  modify_reg_pav ();
   FOR_EACH_BB (bb)
     {
       bb_info = BB_INFO (bb);
       
-      /* Reload can assign the same hard register to uninitialized
-	 pseudo-register and early clobbered pseudo-register in an
-	 insn if the pseudo-register is used first time in given BB
-	 and not lived at the BB start.  To prevent this we don't
-	 change life information for such pseudo-registers.  */
-      bitmap_a_or_b (bb_info->pavin, bb_info->pavin, bb_info->earlyclobber);
       bitmap_a_and_b (bb->global_live_at_start, bb->global_live_at_start,
 		      bb_info->pavin);
       bitmap_a_and_b (bb->global_live_at_end, bb->global_live_at_end,