simplify-rtx.c (avoid_constant_pool_reference): Support offsetted addresses in the...

2005-05-26  Paolo Bonzini  <bonzini@gnu.org>

	* simplify-rtx.c (avoid_constant_pool_reference): Support
	offsetted addresses in the constant pool.

From-SVN: r100198

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3c79b2a478ab3ab9a43c3f2ec296d53654bc5a55..ffd7b7f0bed912c24e50e94b5022999e2134711a 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2005-05-26  Paolo Bonzini  <bonzini@gnu.org>
+
+       * simplify-rtx.c (avoid_constant_pool_reference): Support
+       offsetted addresses in the constant pool.
+
 2005-05-26  Paolo Bonzini  <bonzini@gnu.org>
 
        * df.h (DF_SUBREGS, df_local_def_available_p, df_insn_modified_p): New.

diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index d7e9da6062f2a2b60380fa10ce2560ae5dfc22b8..338978992df8b1e8b6f41d5d76447ad26608c063 100644 (file)
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -145,6 +145,7 @@ avoid_constant_pool_reference (rtx x)
 {
   rtx c, tmp, addr;
   enum machine_mode cmode;
+  HOST_WIDE_INT offset = 0;
 
   switch (GET_CODE (x))
     {
@@ -173,26 +174,40 @@ avoid_constant_pool_reference (rtx x)
   /* Call target hook to avoid the effects of -fpic etc....  */
   addr = targetm.delegitimize_address (addr);
 
+  /* Split the address into a base and integer offset.  */
+  if (GET_CODE (addr) == CONST
+      && GET_CODE (XEXP (addr, 0)) == PLUS
+      && GET_CODE (XEXP (XEXP (addr, 0), 1)) == CONST_INT)
+    {
+      offset = INTVAL (XEXP (XEXP (addr, 0), 1));
+      addr = XEXP (XEXP (addr, 0), 0);
+    }
+
   if (GET_CODE (addr) == LO_SUM)
     addr = XEXP (addr, 1);
 
-  if (GET_CODE (addr) != SYMBOL_REF
-      || ! CONSTANT_POOL_ADDRESS_P (addr))
-    return x;
-
-  c = get_pool_constant (addr);
-  cmode = get_pool_mode (addr);
-
-  /* If we're accessing the constant in a different mode than it was
-     originally stored, attempt to fix that up via subreg simplifications.
-     If that fails we have no choice but to return the original memory.  */
-  if (cmode != GET_MODE (x))
+  /* If this is a constant pool reference, we can turn it into its
+     constant and hope that simplifications happen.  */
+  if (GET_CODE (addr) == SYMBOL_REF
+      && CONSTANT_POOL_ADDRESS_P (addr))
     {
-      c = simplify_subreg (GET_MODE (x), c, cmode, 0);
-      return c ? c : x;
+      c = get_pool_constant (addr);
+      cmode = get_pool_mode (addr);
+
+      /* If we're accessing the constant in a different mode than it was
+         originally stored, attempt to fix that up via subreg simplifications.
+         If that fails we have no choice but to return the original memory.  */
+      if (offset != 0 || cmode != GET_MODE (x))
+        {
+          rtx tem = simplify_subreg (GET_MODE (x), c, cmode, offset);
+          if (tem && CONSTANT_P (tem))
+            return tem;
+        }
+      else
+        return c;
     }
 
-  return c;
+  return x;
 }
 \f
 /* Make a unary operation by first seeing if it folds and otherwise making