[Bug rtl-optimization/55247] [4.8 Regression] internal compiler error: Max. number of generated reload insns per insn is achieved (90)

["hjl.tools at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55247

--- Comment #6 from H.J. Lu <hjl.tools at gmail dot com> 2012-11-10 02:30:16 UTC ---
Something like this:

diff --git a/gcc/explow.c b/gcc/explow.c
index 6109832..9ec38f9 100644
--- a/gcc/explow.c
+++ b/gcc/explow.c
@@ -84,12 +84,22 @@ plus_constant (enum machine_mode mode, rtx x, HOST_WIDE_INT 
c)
   rtx y;
   rtx tem;
   int all_constant = 0;
+  enum machine_mode zero_extend_mode;

   gcc_assert (GET_MODE (x) == VOIDmode || GET_MODE (x) == mode);

   if (c == 0)
     return x;

+  if (GET_CODE (x) == ZERO_EXTEND)
+    {
+      zero_extend_mode = GET_MODE (x);
+      x = XEXP (x, 0);
+      mode = GET_MODE (x);
+    }
+  else
+    zero_extend_mode = VOIDmode;
+
  restart:

   code = GET_CODE (x);
@@ -195,7 +205,11 @@ plus_constant (enum machine_mode mode, rtx x,
HOST_WIDE_INT
 c)
   else if (all_constant)
     return gen_rtx_CONST (mode, x);
   else
-    return x;
+    {
+      if (zero_extend_mode != VOIDmode)
+    x = gen_rtx_ZERO_EXTEND (zero_extend_mode, x);
+      return x;
+    }
 }
 ^L
 /* If X is a sum, return a new sum like X but lacking any constant terms.
diff --git a/gcc/recog.c b/gcc/recog.c
index ee68e30..d3dd591 100644
--- a/gcc/recog.c
+++ b/gcc/recog.c
@@ -1934,15 +1934,21 @@ int
 offsettable_address_addr_space_p (int strictp, enum machine_mode mode, rtx y,
                   addr_space_t as)
 {
-  enum rtx_code ycode = GET_CODE (y);
+  enum rtx_code ycode;
   rtx z;
-  rtx y1 = y;
+  rtx y1;
   rtx *y2;
   int (*addressp) (enum machine_mode, rtx, addr_space_t) =
     (strictp ? strict_memory_address_addr_space_p
          : memory_address_addr_space_p);
   unsigned int mode_sz = GET_MODE_SIZE (mode);

+  if (GET_CODE (y) == ZERO_EXTEND)
+    y = XEXP (y, 0);
+
+  ycode = GET_CODE (y);
+  y1 = y;
+
   if (CONSTANT_ADDRESS_P (y))
     return 1;