regmove.c (optimize_reg_copy_1): Undo Aug 18 change.

        * regmove.c (optimize_reg_copy_1): Undo Aug 18 change.  Update
        REG_N_CALLS_CROSSED and REG_LIVE_LENGH if and only if we change
        where a register is live.

From-SVN: r24718

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d80ee4922511cacaa51555e0b675f2e22f9bab22..b299bcdb1d96c46177bf1484a536d6a68919eafb 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+Sun Jan 17 19:23:20 1999  Jeffrey A Law  (law@cygnus.com)
+
+        * regmove.c (optimize_reg_copy_1): Undo Aug 18 change.  Update
+        REG_N_CALLS_CROSSED and REG_LIVE_LENGH if and only if we change
+        where a register is live.
+
+Sun Jan 17 03:20:47 1999  H.J. Lu  (hjl@gnu.org)
+
+       * reg-stack.c (subst_stack_regs_pat): Abort if the destination
+       of a FP conditional move is not on the FP register stack.
+
 Sun Jan 17 01:15:04 PST 1999 Jeff Law  (law@cygnus.com)
 
        * version.c: Bump for snapshot.

diff --git a/gcc/regmove.c b/gcc/regmove.c
index 87de0fb9808b3c7eb789ca07bd9d78553e05a670..9697fa23dc80274ffcf6ce6a13398ec36620ed1a 100644 (file)
--- a/gcc/regmove.c
+++ b/gcc/regmove.c
@@ -253,10 +253,10 @@ optimize_reg_copy_1 (insn, dest, src)
          && GET_MODE (XEXP (note, 0)) == GET_MODE (src))
        {
          int failed = 0;
-         int length = 0;
          int d_length = 0;
-         int n_calls = 0;
+         int s_length = 0;
          int d_n_calls = 0;
+         int s_n_calls = 0;
 
          /* We can do the optimization.  Scan forward from INSN again,
             replacing regs as we go.  Set FAILED if a replacement can't
@@ -290,42 +290,14 @@ optimize_reg_copy_1 (insn, dest, src)
                         insn in the REG_N_REFS updates below.  If this is not
                         correct, no great harm is done.
 
-
-                        We do not undo this substitution if something later
-                        fails.  Therefore, we must update the other REG_N_*
-                        counters now to keep them accurate.  */
+                        Since we do not know if we will change the lifetime of
+                        SREGNO or DREGNO, we must not update REG_LIVE_LENGTH
+                        or REG_N_CALLS_CROSSED at this time.   */
                      if (sregno >= FIRST_PSEUDO_REGISTER)
-                       {
-                         REG_N_REFS (sregno) -= loop_depth;
-
-                         if (REG_LIVE_LENGTH (sregno) >= 0)
-                           {
-                             REG_LIVE_LENGTH (sregno) -= length;
-                             /* REG_LIVE_LENGTH is only an approximation after
-                                combine if sched is not run, so make sure that
-                                we still have a reasonable value.  */
-                             if (REG_LIVE_LENGTH (sregno) < 2)
-                               REG_LIVE_LENGTH (sregno) = 2;
-                           }
-
-                         REG_N_CALLS_CROSSED (sregno) -= n_calls;
-                       }
+                       REG_N_REFS (sregno) -= loop_depth;
 
                      if (dregno >= FIRST_PSEUDO_REGISTER)
-                       {
-                         REG_N_REFS (dregno) += loop_depth;
-
-                         if (REG_LIVE_LENGTH (dregno) >= 0)
-                           REG_LIVE_LENGTH (dregno) += d_length;
-
-                         REG_N_CALLS_CROSSED (dregno) += d_n_calls;
-                       }
-
-                     /* We've done a substitution, clear the counters.  */
-                     length = 0;
-                     d_length = 0;
-                     n_calls = 0;
-                     d_n_calls = 0;
+                       REG_N_REFS (dregno) += loop_depth;
                    }
                  else
                    {
@@ -334,9 +306,10 @@ optimize_reg_copy_1 (insn, dest, src)
                    }
                }
 
-             /* Count the insns and CALL_INSNs passed.  If we passed the
-                death note of DEST, show increased live length.  */
-             length++;
+             /* For SREGNO, count the total number of insns scanned.
+                For DREGNO, count the total number of insns scanned after
+                passing the death note for DREGNO.  */
+             s_length++;
              if (dest_death)
                d_length++;
 
@@ -344,7 +317,9 @@ optimize_reg_copy_1 (insn, dest, src)
                 as a call that has been crossed.  Otherwise, count it.  */
              if (q != p && GET_CODE (q) == CALL_INSN)
                {
-                 n_calls++;
+                 /* Similarly, total calls for SREGNO, total calls beyond
+                    the death note for DREGNO.  */
+                 s_n_calls++;
                  if (dest_death)
                    d_n_calls++;
                }
@@ -364,11 +339,13 @@ optimize_reg_copy_1 (insn, dest, src)
 
          if (! failed)
            {
+             /* These counters need to be updated if and only if we are
+                going to move the REG_DEAD note.  */
              if (sregno >= FIRST_PSEUDO_REGISTER)
                {
                  if (REG_LIVE_LENGTH (sregno) >= 0)
                    {
-                     REG_LIVE_LENGTH (sregno) -= length;
+                     REG_LIVE_LENGTH (sregno) -= s_length;
                      /* REG_LIVE_LENGTH is only an approximation after
                         combine if sched is not run, so make sure that we
                         still have a reasonable value.  */
@@ -376,15 +353,7 @@ optimize_reg_copy_1 (insn, dest, src)
                        REG_LIVE_LENGTH (sregno) = 2;
                    }
 
-                 REG_N_CALLS_CROSSED (sregno) -= n_calls;
-               }
-
-             if (dregno >= FIRST_PSEUDO_REGISTER)
-               {
-                 if (REG_LIVE_LENGTH (dregno) >= 0)
-                   REG_LIVE_LENGTH (dregno) += d_length;
-
-                 REG_N_CALLS_CROSSED (dregno) += d_n_calls;
+                 REG_N_CALLS_CROSSED (sregno) -= s_n_calls;
                }
 
              /* Move death note of SRC from P to INSN.  */
@@ -398,6 +367,15 @@ optimize_reg_copy_1 (insn, dest, src)
            {
              XEXP (dest_death, 1) = REG_NOTES (p);
              REG_NOTES (p) = dest_death;
+
+             if (dregno >= FIRST_PSEUDO_REGISTER)
+               {
+                 /* If and only if we are moving the death note for DREGNO,
+                    then we need to update its counters.  */
+                 if (REG_LIVE_LENGTH (dregno) >= 0)
+                   REG_LIVE_LENGTH (dregno) += d_length;
+                 REG_N_CALLS_CROSSED (dregno) += d_n_calls;
+               }
            }
 
          return ! failed;