combine.c: Fix header comments.

2003-05-14  Eric Christopher  <echristo@redhat.com>

	* combine.c: Fix header comments.
	(distribute_notes): Remove usage of elim_i1, elim_i2. Propagate
	to all calls and prototype.

From-SVN: r66813

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 81d9028302b737157742a1ea7d8b4e8d8562c7cd..f58515ea3e23e887c362522ae8f59d0fecd11b18 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,7 +1,13 @@
+2003-05-14  Eric Christopher  <echristo@redhat.com>
+
+       * combine.c: Fix header comments.
+       (distribute_notes): Remove usage of elim_i1, elim_i2. Propagate
+       to all calls and prototype.
+
 2003-05-14  Roger Sayle  <roger@eyesopen.com>
 
        PR optimization/10764
-       * config/i386/i386.md (atan2df3, atan2sf3, atan2xf3, atan2tf3): 
+       * config/i386/i386.md (atan2df3, atan2sf3, atan2xf3, atan2tf3):
        Add an explicit clobber to show that UNSPEC_FPATAN clobbers st(1).
        (*fyl2x_sfxf3, *fyl2x_dfxf3, *fyl2x_xf3, *fyl2x_tfxf3):  Likewise,
        add an explicit clobber to show that UNSPEC_FYL2X clobbers st(1).
@@ -67,7 +73,7 @@
        (libgcov.a): Depend on libgcc.a.
        (gcov.o, gcov-dump.o): Add gcov-io.c.
        * mklibgcc.in (libgcov_c_dep): Use $(srcdir).
-       
+
        * loop.c (check_dbra_loop): Factor common test.
 
 2003-05-14  Ben Elliston  <bje@wasabisystems.com>

diff --git a/gcc/combine.c b/gcc/combine.c
index 6e3bbb2fb56d0bb59ea5be9cc9ea35c03f884b39..bff8b08f5bfa61770a5fe8d67dca71136d959161 100644 (file)
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -53,10 +53,6 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
    flow.c aren't completely updated:
 
    - reg_live_length is not updated
-   - reg_n_refs is not adjusted in the rare case when a register is
-     no longer required in a computation
-   - there are extremely rare cases (see distribute_regnotes) when a
-     REG_DEAD note is lost
    - a LOG_LINKS entry that refers to an insn with multiple SETs may be
      removed because there is no way to know which register it was
      linking
@@ -413,7 +409,7 @@ static void reg_dead_at_p_1 PARAMS ((rtx, rtx, void *));
 static int reg_dead_at_p       PARAMS ((rtx, rtx));
 static void move_deaths                PARAMS ((rtx, rtx, int, rtx, rtx *));
 static int reg_bitfield_target_p  PARAMS ((rtx, rtx));
-static void distribute_notes   PARAMS ((rtx, rtx, rtx, rtx, rtx, rtx));
+static void distribute_notes   PARAMS ((rtx, rtx, rtx, rtx));
 static void distribute_links   PARAMS ((rtx));
 static void mark_used_regs_combine PARAMS ((rtx));
 static int insn_cuid           PARAMS ((rtx));
@@ -2492,7 +2488,7 @@ try_combine (i3, i2, i1, new_direct_jump_p)
          REG_N_DEATHS (REGNO (XEXP (note, 0)))++;
 
       distribute_notes (new_other_notes, undobuf.other_insn,
-                       undobuf.other_insn, NULL_RTX, NULL_RTX, NULL_RTX);
+                       undobuf.other_insn, NULL_RTX);
     }
 #ifdef HAVE_cc0
   /* If I2 is the setter CC0 and I3 is the user CC0 then check whether
@@ -2516,15 +2512,6 @@ try_combine (i3, i2, i1, new_direct_jump_p)
     rtx i3links, i2links, i1links = 0;
     rtx midnotes = 0;
     unsigned int regno;
-    /* Compute which registers we expect to eliminate.  newi2pat may be setting
-       either i3dest or i2dest, so we must check it.  Also, i1dest may be the
-       same as i3dest, in which case newi2pat may be setting i1dest.  */
-    rtx elim_i2 = ((newi2pat && reg_set_p (i2dest, newi2pat))
-                  || i2dest_in_i2src || i2dest_in_i1src
-                  ? 0 : i2dest);
-    rtx elim_i1 = (i1 == 0 || i1dest_in_i1src
-                  || (newi2pat && reg_set_p (i1dest, newi2pat))
-                  ? 0 : i1dest);
 
     /* Get the old REG_NOTES and LOG_LINKS from all our insns and
        clear them.  */
@@ -2655,17 +2642,13 @@ try_combine (i3, i2, i1, new_direct_jump_p)
 
     /* Distribute all the LOG_LINKS and REG_NOTES from I1, I2, and I3.  */
     if (i3notes)
-      distribute_notes (i3notes, i3, i3, newi2pat ? i2 : NULL_RTX,
-                       elim_i2, elim_i1);
+      distribute_notes (i3notes, i3, i3, newi2pat ? i2 : NULL_RTX);
     if (i2notes)
-      distribute_notes (i2notes, i2, i3, newi2pat ? i2 : NULL_RTX,
-                       elim_i2, elim_i1);
+      distribute_notes (i2notes, i2, i3, newi2pat ? i2 : NULL_RTX);
     if (i1notes)
-      distribute_notes (i1notes, i1, i3, newi2pat ? i2 : NULL_RTX,
-                       elim_i2, elim_i1);
+      distribute_notes (i1notes, i1, i3, newi2pat ? i2 : NULL_RTX);
     if (midnotes)
-      distribute_notes (midnotes, NULL_RTX, i3, newi2pat ? i2 : NULL_RTX,
-                       elim_i2, elim_i1);
+      distribute_notes (midnotes, NULL_RTX, i3, newi2pat ? i2 : NULL_RTX);
 
     /* Distribute any notes added to I2 or I3 by recog_for_combine.  We
        know these are REG_UNUSED and want them to go to the desired insn,
@@ -2678,7 +2661,7 @@ try_combine (i3, i2, i1, new_direct_jump_p)
          if (GET_CODE (XEXP (temp, 0)) == REG)
            REG_N_DEATHS (REGNO (XEXP (temp, 0)))++;
 
-       distribute_notes (new_i2_notes, i2, i2, NULL_RTX, NULL_RTX, NULL_RTX);
+       distribute_notes (new_i2_notes, i2, i2, NULL_RTX);
       }
 
     if (new_i3_notes)
@@ -2687,7 +2670,7 @@ try_combine (i3, i2, i1, new_direct_jump_p)
          if (GET_CODE (XEXP (temp, 0)) == REG)
            REG_N_DEATHS (REGNO (XEXP (temp, 0)))++;
 
-       distribute_notes (new_i3_notes, i3, i3, NULL_RTX, NULL_RTX, NULL_RTX);
+       distribute_notes (new_i3_notes, i3, i3, NULL_RTX);
       }
 
     /* If I3DEST was used in I3SRC, it really died in I3.  We may need to
@@ -2705,12 +2688,11 @@ try_combine (i3, i2, i1, new_direct_jump_p)
        if (newi2pat && reg_set_p (i3dest_killed, newi2pat))
          distribute_notes (gen_rtx_EXPR_LIST (REG_DEAD, i3dest_killed,
                                               NULL_RTX),
-                           NULL_RTX, i2, NULL_RTX, elim_i2, elim_i1);
+                           NULL_RTX, i2, NULL_RTX);
        else
          distribute_notes (gen_rtx_EXPR_LIST (REG_DEAD, i3dest_killed,
                                               NULL_RTX),
-                           NULL_RTX, i3, newi2pat ? i2 : NULL_RTX,
-                           elim_i2, elim_i1);
+                           NULL_RTX, i3, newi2pat ? i2 : NULL_RTX);
       }
 
     if (i2dest_in_i2src)
@@ -2720,11 +2702,10 @@ try_combine (i3, i2, i1, new_direct_jump_p)
 
        if (newi2pat && reg_set_p (i2dest, newi2pat))
          distribute_notes (gen_rtx_EXPR_LIST (REG_DEAD, i2dest, NULL_RTX),
-                           NULL_RTX, i2, NULL_RTX, NULL_RTX, NULL_RTX);
+                           NULL_RTX, i2, NULL_RTX);
        else
          distribute_notes (gen_rtx_EXPR_LIST (REG_DEAD, i2dest, NULL_RTX),
-                           NULL_RTX, i3, newi2pat ? i2 : NULL_RTX,
-                           NULL_RTX, NULL_RTX);
+                           NULL_RTX, i3, newi2pat ? i2 : NULL_RTX);
       }
 
     if (i1dest_in_i1src)
@@ -2734,11 +2715,10 @@ try_combine (i3, i2, i1, new_direct_jump_p)
 
        if (newi2pat && reg_set_p (i1dest, newi2pat))
          distribute_notes (gen_rtx_EXPR_LIST (REG_DEAD, i1dest, NULL_RTX),
-                           NULL_RTX, i2, NULL_RTX, NULL_RTX, NULL_RTX);
+                           NULL_RTX, i2, NULL_RTX);
        else
          distribute_notes (gen_rtx_EXPR_LIST (REG_DEAD, i1dest, NULL_RTX),
-                           NULL_RTX, i3, newi2pat ? i2 : NULL_RTX,
-                           NULL_RTX, NULL_RTX);
+                           NULL_RTX, i3, newi2pat ? i2 : NULL_RTX);
       }
 
     distribute_links (i3links);
@@ -12550,19 +12530,14 @@ reg_bitfield_target_p (x, body)
    as appropriate.  I3 and I2 are the insns resulting from the combination
    insns including FROM (I2 may be zero).
 
-   ELIM_I2 and ELIM_I1 are either zero or registers that we know will
-   not need REG_DEAD notes because they are being substituted for.  This
-   saves searching in the most common cases.
-
    Each note in the list is either ignored or placed on some insns, depending
    on the type of note.  */
 
 static void
-distribute_notes (notes, from_insn, i3, i2, elim_i2, elim_i1)
+distribute_notes (notes, from_insn, i3, i2)
      rtx notes;
      rtx from_insn;
      rtx i3, i2;
-     rtx elim_i2, elim_i1;
 {
   rtx note, next_note;
   rtx tem;
@@ -12824,10 +12799,6 @@ distribute_notes (notes, from_insn, i3, i2, elim_i2, elim_i1)
                   && reg_referenced_p (XEXP (note, 0), PATTERN (i2)))
            place = i2;
 
-         if (rtx_equal_p (XEXP (note, 0), elim_i2)
-             || rtx_equal_p (XEXP (note, 0), elim_i1))
-           break;
-
          if (place == 0)
            {
              basic_block bb = this_basic_block;
@@ -12885,7 +12856,7 @@ distribute_notes (notes, from_insn, i3, i2, elim_i2, elim_i1)
                          PATTERN (tem) = pc_rtx;
 
                          distribute_notes (REG_NOTES (tem), tem, tem,
-                                           NULL_RTX, NULL_RTX, NULL_RTX);
+                                           NULL_RTX);
                          distribute_links (LOG_LINKS (tem));
 
                          PUT_CODE (tem, NOTE);
@@ -12900,7 +12871,7 @@ distribute_notes (notes, from_insn, i3, i2, elim_i2, elim_i1)
 
                              distribute_notes (REG_NOTES (cc0_setter),
                                                cc0_setter, cc0_setter,
-                                               NULL_RTX, NULL_RTX, NULL_RTX);
+                                               NULL_RTX);
                              distribute_links (LOG_LINKS (cc0_setter));
 
                              PUT_CODE (cc0_setter, NOTE);
@@ -13048,7 +13019,7 @@ distribute_notes (notes, from_insn, i3, i2, elim_i2, elim_i1)
                                = gen_rtx_EXPR_LIST (REG_DEAD, piece, NULL_RTX);
 
                              distribute_notes (new_note, place, place,
-                                               NULL_RTX, NULL_RTX, NULL_RTX);
+                                               NULL_RTX);
                            }
                          else if (! refers_to_regno_p (i, i + 1,
                                                        PATTERN (place), 0)