re PR rtl-optimization/12828 (-floop-optimize is unstable on PowerPC (float to int...

2003-12-21  Dale Johannesen  <dalej@apple.com>

        PR optimization/12828
        * loop.c:  Add find_regs_nested to look inside CLOBBER(MEM).
        (scan_loop):  Call it.
        * regclass.c (reg_scan_mark_regs):  Look inside CLOBBER(MEM).

From-SVN: r74935

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 60244baf0c1728741446e9a631ae586dcffa17d1..6d077413ed3e63252abff825fa435af3a97c2b10 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2003-12-22  Dale Johannesen  <dalej@apple.com>
+
+        PR optimization/12828
+        * loop.c:  Add find_regs_nested to look inside CLOBBER(MEM).
+        (scan_loop):  Call it.
+        * regclass.c (reg_scan_mark_regs):  Look inside CLOBBER(MEM).
+
 2003-12-22  Andrew Pinski  <pinskia@physics.uc.edu>
 
        PR c/9163

diff --git a/gcc/loop.c b/gcc/loop.c
index 58fc1a0ac4eaf21b898382334f73a3be0e234507..4ee83447a6998eaac83c4599e73cf58f325d443d 100644 (file)
--- a/gcc/loop.c
+++ b/gcc/loop.c
@@ -255,6 +255,7 @@ static void count_one_set (struct loop_regs *, rtx, rtx, rtx *);
 static void note_addr_stored (rtx, rtx, void *);
 static void note_set_pseudo_multiple_uses (rtx, rtx, void *);
 static int loop_reg_used_before_p (const struct loop *, rtx, rtx);
+static rtx find_regs_nested (rtx, rtx);
 static void scan_loop (struct loop*, int);
 #if 0
 static void replace_call_address (rtx, rtx, rtx);
@@ -573,6 +574,32 @@ next_insn_in_loop (const struct loop *loop, rtx insn)
   return insn;
 }
 
+/* Find any register references hidden inside X and add them to
+   the dependency list DEPS.  This is used to look inside CLOBBER (MEM
+   when checking whether a PARALLEL can be pulled out of a loop.  */
+
+static rtx
+find_regs_nested (rtx deps, rtx x)
+{
+  enum rtx_code code = GET_CODE (x);
+  if (code == REG)
+    deps = gen_rtx_EXPR_LIST (VOIDmode, x, deps);
+  else
+    {
+      const char *fmt = GET_RTX_FORMAT (code);
+      int i, j;
+      for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
+       {
+         if (fmt[i] == 'e')
+           deps = find_regs_nested (deps, XEXP (x, i));
+         else if (fmt[i] == 'E')
+           for (j = 0; j < XVECLEN (x, i); j++)
+             deps = find_regs_nested (deps, XVECEXP (x, i, j));
+       }
+    }
+  return deps;
+}
+
 /* Optimize one loop described by LOOP.  */
 
 /* ??? Could also move memory writes out of loops if the destination address
@@ -776,7 +803,9 @@ scan_loop (struct loop *loop, int flags)
                }
 
              /* For parallels, add any possible uses to the dependencies, as
-                we can't move the insn without resolving them first.  */
+                we can't move the insn without resolving them first.
+                MEMs inside CLOBBERs may also reference registers; these
+                count as implicit uses.  */
              if (GET_CODE (PATTERN (p)) == PARALLEL)
                {
                  for (i = 0; i < XVECLEN (PATTERN (p), 0); i++)
@@ -786,6 +815,10 @@ scan_loop (struct loop *loop, int flags)
                        dependencies
                          = gen_rtx_EXPR_LIST (VOIDmode, XEXP (x, 0),
                                               dependencies);
+                     else if (GET_CODE (x) == CLOBBER 
+                              && GET_CODE (XEXP (x, 0)) == MEM)
+                       dependencies = find_regs_nested (dependencies, 
+                                                 XEXP (XEXP (x, 0), 0));
                    }
                }
 

diff --git a/gcc/regclass.c b/gcc/regclass.c
index 439f9f6b77340909c3c226ed7ce294e12d1b4b86..2e4dc61be32fd6a1698aa9ecec9d226a5f6e27ae 100644 (file)
--- a/gcc/regclass.c
+++ b/gcc/regclass.c
@@ -2406,6 +2406,8 @@ reg_scan_mark_refs (rtx x, rtx insn, int note_flag, unsigned int min_regno)
            REG_N_SETS (REGNO (reg))++;
            REG_N_REFS (REGNO (reg))++;
          }
+       else if (GET_CODE (reg) == MEM)
+         reg_scan_mark_refs (XEXP (reg, 0), insn, note_flag, min_regno);
       }
       break;