Import gcc-3.3.2. Only the compiler. ada frontend removed for space

considerations.

1 files changed, 25 insertions, 33 deletions

diff --git a/gnu/usr.bin/gcc/gcc/flow.c b/gnu/usr.bin/gcc/gcc/flow.c
index 9f5e1924e91..7882b25ae9a 100644
--- a/gnu/usr.bin/gcc/gcc/flow.c
+++ b/gnu/usr.bin/gcc/gcc/flow.c
@@ -1,6 +1,6 @@
 /* Data flow analysis for GNU compiler.
    Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-   1999, 2000, 2001, 2002, 2004 Free Software Foundation, Inc.
+   1999, 2000, 2001, 2002 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -431,8 +431,9 @@ life_analysis (f, file, flags)
   SET_HARD_REG_BIT (elim_reg_set, FRAME_POINTER_REGNUM);
 #endif
 
+
 #ifdef CANNOT_CHANGE_MODE_CLASS
-  init_subregs_of_mode ();
+  bitmap_initialize (&subregs_of_mode, 1);
 #endif
 
   if (! optimize)
@@ -1798,9 +1799,8 @@ propagate_one_insn (pbi, insn)
 					      current_function_return_rtx,
 					      (rtx *) 0)))
 	      {
-		enum rtx_code code = global_regs[i] ? SET : CLOBBER;
 		/* We do not want REG_UNUSED notes for these registers.  */
-		mark_set_1 (pbi, code, regno_reg_rtx[i], cond, insn,
+		mark_set_1 (pbi, CLOBBER, regno_reg_rtx[i], cond, insn,
 			    pbi->flags & ~(PROP_DEATH_NOTES | PROP_REG_INFO));
 	      }
 	}
@@ -2292,22 +2292,14 @@ insn_dead_p (pbi, x, call_ok, notes)
     }
 
   /* A CLOBBER of a pseudo-register that is dead serves no purpose.  That
-     is not necessarily true for hard registers until after reload.  */
-  else if (code == CLOBBER)
-    {
-      if (GET_CODE (XEXP (x, 0)) == REG
-	  && (REGNO (XEXP (x, 0)) >= FIRST_PSEUDO_REGISTER
-	      || reload_completed)
-	  && ! REGNO_REG_SET_P (pbi->reg_live, REGNO (XEXP (x, 0))))
-	return 1;
-    }
-
-  /* ??? A base USE is a historical relic.  It ought not be needed anymore.
-     Instances where it is still used are either (1) temporary and the USE
-     escaped the pass, (2) cruft and the USE need not be emitted anymore,
-     or (3) hiding bugs elsewhere that are not properly representing data
-     flow.  */
-
+     is not necessarily true for hard registers.  */
+  else if (code == CLOBBER && GET_CODE (XEXP (x, 0)) == REG
+	   && REGNO (XEXP (x, 0)) >= FIRST_PSEUDO_REGISTER
+	   && ! REGNO_REG_SET_P (pbi->reg_live, REGNO (XEXP (x, 0))))
+    return 1;
+
+  /* We do not check other CLOBBER or USE here.  An insn consisting of just
+     a CLOBBER or just a USE should not be deleted.  */
   return 0;
 }
 
@@ -2821,18 +2813,10 @@ mark_set_1 (pbi, code, reg, cond, insn, flags)
 		     in ASM_OPERANDs.  If these registers get replaced,
 		     we might wind up changing the semantics of the insn,
 		     even if reload can make what appear to be valid
-		     assignments later.
-
-		     We don't build a LOG_LINK for global registers to
-		     or from a function call.  We don't want to let
-		     combine think that it knows what is going on with
-		     global registers.  */
+		     assignments later.  */
 		  if (y && (BLOCK_NUM (y) == blocknum)
 		      && (regno_first >= FIRST_PSEUDO_REGISTER
-			  || (asm_noperands (PATTERN (y)) < 0
-			      && ! ((GET_CODE (insn) == CALL_INSN
-				     || GET_CODE (y) == CALL_INSN)
-				    && global_regs[regno_first]))))
+			  || asm_noperands (PATTERN (y)) < 0))
 		    LOG_LINKS (y) = alloc_INSN_LIST (insn, LOG_LINKS (y));
 		}
 	    }
@@ -3850,7 +3834,11 @@ mark_used_regs (pbi, x, cond, insn)
 
     case SUBREG:
 #ifdef CANNOT_CHANGE_MODE_CLASS
-      record_subregs_of_mode (x);
+      if (GET_CODE (SUBREG_REG (x)) == REG
+	  && REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER)
+	bitmap_set_bit (&subregs_of_mode, REGNO (SUBREG_REG (x))
+					  * MAX_MACHINE_MODE
+					  + GET_MODE (x));
 #endif
 
       /* While we're here, optimize this case.  */
@@ -3895,8 +3883,12 @@ mark_used_regs (pbi, x, cond, insn)
 	       || GET_CODE (testreg) == SUBREG)
 	  {
 #ifdef CANNOT_CHANGE_MODE_CLASS
-	    if (GET_CODE (testreg) == SUBREG)
-	      record_subregs_of_mode (testreg);
+	    if (GET_CODE (testreg) == SUBREG
+		&& GET_CODE (SUBREG_REG (testreg)) == REG
+		&& REGNO (SUBREG_REG (testreg)) >= FIRST_PSEUDO_REGISTER)
+	      bitmap_set_bit (&subregs_of_mode, REGNO (SUBREG_REG (testreg))
+						* MAX_MACHINE_MODE
+						+ GET_MODE (testreg));
 #endif
 
 	    /* Modifying a single register in an alternate mode