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

4 files changed, 93 insertions, 6 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 68b9043..2493946 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2016-02-01  Jakub Jelinek  <jakub@redhat.com>
+
+	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.
+
 2016-02-01  Jeff Law  <law@redhat.com>
 
 	PR tree-optimization/69580
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:
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 73b0ce8..1f8ddd0 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2016-02-01  Jakub Jelinek  <jakub@redhat.com>
 
+	PR rtl-optimization/69592
+	* gcc.dg/pr69592.c: New test.
+
 	PR preprocessor/69543
 	PR c/69558
 	* gcc.dg/pr69543.c: New test.
diff --git a/gcc/testsuite/gcc.dg/pr69592.c b/gcc/testsuite/gcc.dg/pr69592.c
new file mode 100644
index 0000000..c791fe9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr69592.c
@@ -0,0 +1,16 @@
+/* PR rtl-optimization/69592 */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+unsigned int
+foo (unsigned int a, unsigned int *b, unsigned int c)
+{
+  unsigned int d;
+#define A(n) d = a + b[n]; if (d < a) c++; a = d;
+#define B(n) A(n##0) A(n##1) A(n##2) A(n##3) A(n##4) A(n##5) A(n##6) A(n##7) A(n##8) A(n##9)
+#define C(n) B(n##0) B(n##1) B(n##2) B(n##3) B(n##4) B(n##5) B(n##6) B(n##7) B(n##8) B(n##9)
+#define D(n) C(n##0) C(n##1) C(n##2) C(n##3) C(n##4) C(n##5) C(n##6) C(n##7) C(n##8) C(n##9)
+#define E(n) D(n##0) D(n##1) D(n##2) D(n##3) D(n##4) D(n##5) D(n##6) D(n##7) D(n##8) D(n##9)
+  C(1) C(2) C(3) C(4) C(5) C(6)
+  return d + c;
+}