re PR rtl-optimization/69592 (Compile-time and memory-use hog in combine)

	PR rtl-optimization/69592
	* rtlanal.c (nonzero_bits_binary_arith_p): New inline function.
	(cached_nonzero_bits): Use it instead of ARITHMETIC_P.
	(num_sign_bit_copies_binary_arith_p): New inline function.
	(cached_num_sign_bit_copies): Use it instead of ARITHMETIC_P.

	* gcc.dg/pr69592.c: New test.

From-SVN: r233059

1 files changed, 66 insertions, 6 deletions

diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c
index 71dfd33..642611f 100644
--- a/gcc/rtlanal.c
+++ b/gcc/rtlanal.c
@@ -4163,6 +4163,36 @@ num_sign_bit_copies (const_rtx x, machine_mode mode)
   return cached_num_sign_bit_copies (x, mode, NULL_RTX, VOIDmode, 0);
 }
 
+/* Return true if nonzero_bits1 might recurse into both operands
+   of X.  */
+
+static inline bool
+nonzero_bits_binary_arith_p (const_rtx x)
+{
+  if (!ARITHMETIC_P (x))
+    return false;
+  switch (GET_CODE (x))
+    {
+    case AND:
+    case XOR:
+    case IOR:
+    case UMIN:
+    case UMAX:
+    case SMIN:
+    case SMAX:
+    case PLUS:
+    case MINUS:
+    case MULT:
+    case DIV:
+    case UDIV:
+    case MOD:
+    case UMOD:
+      return true;
+    default:
+      return false;
+    }
+}
+
 /* The function cached_nonzero_bits is a wrapper around nonzero_bits1.
    It avoids exponential behavior in nonzero_bits1 when X has
    identical subexpressions on the first or the second level.  */
@@ -4179,7 +4209,7 @@ cached_nonzero_bits (const_rtx x, machine_mode mode, const_rtx known_x,
      nonzero_bits1 on X with the subexpressions as KNOWN_X and the
      precomputed value for the subexpression as KNOWN_RET.  */
 
-  if (ARITHMETIC_P (x))
+  if (nonzero_bits_binary_arith_p (x))
     {
       rtx x0 = XEXP (x, 0);
       rtx x1 = XEXP (x, 1);
@@ -4191,13 +4221,13 @@ cached_nonzero_bits (const_rtx x, machine_mode mode, const_rtx known_x,
 						   known_mode, known_ret));
 
       /* Check the second level.  */
-      if (ARITHMETIC_P (x0)
+      if (nonzero_bits_binary_arith_p (x0)
 	  && (x1 == XEXP (x0, 0) || x1 == XEXP (x0, 1)))
 	return nonzero_bits1 (x, mode, x1, mode,
 			      cached_nonzero_bits (x1, mode, known_x,
 						   known_mode, known_ret));
 
-      if (ARITHMETIC_P (x1)
+      if (nonzero_bits_binary_arith_p (x1)
 	  && (x0 == XEXP (x1, 0) || x0 == XEXP (x1, 1)))
 	return nonzero_bits1 (x, mode, x0, mode,
 			      cached_nonzero_bits (x0, mode, known_x,
@@ -4269,6 +4299,8 @@ nonzero_bits1 (const_rtx x, machine_mode mode, const_rtx known_x,
       return nonzero;
     }
 
+  /* Please keep nonzero_bits_binary_arith_p above in sync with
+     the code in the switch below.  */
   code = GET_CODE (x);
   switch (code)
     {
@@ -4672,6 +4704,32 @@ nonzero_bits1 (const_rtx x, machine_mode mode, const_rtx known_x,
 #undef cached_num_sign_bit_copies
 
 
+/* Return true if num_sign_bit_copies1 might recurse into both operands
+   of X.  */
+
+static inline bool
+num_sign_bit_copies_binary_arith_p (const_rtx x)
+{
+  if (!ARITHMETIC_P (x))
+    return false;
+  switch (GET_CODE (x))
+    {
+    case IOR:
+    case AND:
+    case XOR:
+    case SMIN:
+    case SMAX:
+    case UMIN:
+    case UMAX:
+    case PLUS:
+    case MINUS:
+    case MULT:
+      return true;
+    default:
+      return false;
+    }
+}
+
 /* The function cached_num_sign_bit_copies is a wrapper around
    num_sign_bit_copies1.  It avoids exponential behavior in
    num_sign_bit_copies1 when X has identical subexpressions on the
@@ -4689,7 +4747,7 @@ cached_num_sign_bit_copies (const_rtx x, machine_mode mode, const_rtx known_x,
      num_sign_bit_copies1 on X with the subexpressions as KNOWN_X and
      the precomputed value for the subexpression as KNOWN_RET.  */
 
-  if (ARITHMETIC_P (x))
+  if (num_sign_bit_copies_binary_arith_p (x))
     {
       rtx x0 = XEXP (x, 0);
       rtx x1 = XEXP (x, 1);
@@ -4703,7 +4761,7 @@ cached_num_sign_bit_copies (const_rtx x, machine_mode mode, const_rtx known_x,
 							    known_ret));
 
       /* Check the second level.  */
-      if (ARITHMETIC_P (x0)
+      if (num_sign_bit_copies_binary_arith_p (x0)
 	  && (x1 == XEXP (x0, 0) || x1 == XEXP (x0, 1)))
 	return
 	  num_sign_bit_copies1 (x, mode, x1, mode,
@@ -4711,7 +4769,7 @@ cached_num_sign_bit_copies (const_rtx x, machine_mode mode, const_rtx known_x,
 							    known_mode,
 							    known_ret));
 
-      if (ARITHMETIC_P (x1)
+      if (num_sign_bit_copies_binary_arith_p (x1)
 	  && (x0 == XEXP (x1, 0) || x0 == XEXP (x1, 1)))
 	return
 	  num_sign_bit_copies1 (x, mode, x0, mode,
@@ -4777,6 +4835,8 @@ num_sign_bit_copies1 (const_rtx x, machine_mode mode, const_rtx known_x,
 	return 1;
     }
 
+  /* Please keep num_sign_bit_copies_binary_arith_p above in sync with
+     the code in the switch below.  */
   switch (code)
     {
     case REG: