[PATCH 1/2] Negative numbers added for sreal class.

	* predict.c (propagate_freq): More elegant sreal API is used.
	(estimate_bb_frequencies): Precomputed constants replaced by integer
	constants.
	* sreal.c (sreal::normalize): New function.
	(sreal::to_int): Likewise.
	(sreal::operator+): Likewise.
	(sreal::operator-): Likewise.
	(sreal::signedless_plus): Likewise.
	(sreal::signedless_minus): Likewise.
	(sreal::operator/): Negative number support is added.
	* sreal.h: Definition of new functions added.
	(inline sreal operator<<): New function.
	(inline sreal operator>>): Likewise.

From-SVN: r218008

4 files changed, 190 insertions, 52 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 562ef8a..48dccf3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,19 @@
+2014-11-24  Martin Liska  <mliska@suse.cz>
+
+	* predict.c (propagate_freq): More elegant sreal API is used.
+	(estimate_bb_frequencies): Precomputed constants replaced by integer
+	constants.
+	* sreal.c (sreal::normalize): New function.
+	(sreal::to_int): Likewise.
+	(sreal::operator+): Likewise.
+	(sreal::operator-): Likewise.
+	(sreal::signedless_plus): Likewise.
+	(sreal::signedless_minus): Likewise.
+	(sreal::operator/): Negative number support is added.
+	* sreal.h: Definition of new functions added.
+	(inline sreal operator<<): New function.
+	(inline sreal operator>>): Likewise.
+
 2014-11-24  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	* config/aarch64/aarch64-protos.h (struct tune_params): Add
diff --git a/gcc/predict.c b/gcc/predict.c
index 779af11..0cfe4a9 100644
--- a/gcc/predict.c
+++ b/gcc/predict.c
@@ -82,7 +82,7 @@ along with GCC; see the file COPYING3.  If not see
 
 /* real constants: 0, 1, 1-1/REG_BR_PROB_BASE, REG_BR_PROB_BASE,
 		   1/REG_BR_PROB_BASE, 0.5, BB_FREQ_MAX.  */
-static sreal real_zero, real_one, real_almost_one, real_br_prob_base,
+static sreal real_almost_one, real_br_prob_base,
 	     real_inv_br_prob_base, real_one_half, real_bb_freq_max;
 
 static void combine_predictions_for_insn (rtx_insn *, basic_block);
@@ -2541,13 +2541,13 @@ propagate_freq (basic_block head, bitmap tovisit)
 	bb->count = bb->frequency = 0;
     }
 
-  BLOCK_INFO (head)->frequency = real_one;
+  BLOCK_INFO (head)->frequency = 1;
   last = head;
   for (bb = head; bb; bb = nextbb)
     {
       edge_iterator ei;
-      sreal cyclic_probability = real_zero;
-      sreal frequency = real_zero;
+      sreal cyclic_probability = 0;
+      sreal frequency = 0;
 
       nextbb = BLOCK_INFO (bb)->next;
       BLOCK_INFO (bb)->next = NULL;
@@ -2572,13 +2572,13 @@ propagate_freq (basic_block head, bitmap tovisit)
 				  * BLOCK_INFO (e->src)->frequency /
 				  REG_BR_PROB_BASE);  */
 
-		sreal tmp (e->probability, 0);
+		sreal tmp = e->probability;
 		tmp *= BLOCK_INFO (e->src)->frequency;
 		tmp *= real_inv_br_prob_base;
 		frequency += tmp;
 	      }
 
-	  if (cyclic_probability == real_zero)
+	  if (cyclic_probability == 0)
 	    {
 	      BLOCK_INFO (bb)->frequency = frequency;
 	    }
@@ -2590,7 +2590,7 @@ propagate_freq (basic_block head, bitmap tovisit)
 	      /* BLOCK_INFO (bb)->frequency = frequency
 					      / (1 - cyclic_probability) */
 
-	      cyclic_probability = real_one - cyclic_probability;
+	      cyclic_probability = sreal (1) - cyclic_probability;
 	      BLOCK_INFO (bb)->frequency = frequency / cyclic_probability;
 	    }
 	}
@@ -2604,7 +2604,7 @@ propagate_freq (basic_block head, bitmap tovisit)
 	     = ((e->probability * BLOCK_INFO (bb)->frequency)
 	     / REG_BR_PROB_BASE); */
 
-	  sreal tmp (e->probability, 0);
+	  sreal tmp = e->probability;
 	  tmp *= BLOCK_INFO (bb)->frequency;
 	  EDGE_INFO (e)->back_edge_prob = tmp * real_inv_br_prob_base;
 	}
@@ -2886,13 +2886,11 @@ estimate_bb_frequencies (bool force)
       if (!real_values_initialized)
         {
 	  real_values_initialized = 1;
-	  real_zero = sreal (0, 0);
-	  real_one = sreal (1, 0);
-	  real_br_prob_base = sreal (REG_BR_PROB_BASE, 0);
-	  real_bb_freq_max = sreal (BB_FREQ_MAX, 0);
+	  real_br_prob_base = REG_BR_PROB_BASE;
+	  real_bb_freq_max = BB_FREQ_MAX;
 	  real_one_half = sreal (1, -1);
-	  real_inv_br_prob_base = real_one / real_br_prob_base;
-	  real_almost_one = real_one - real_inv_br_prob_base;
+	  real_inv_br_prob_base = sreal (1) / real_br_prob_base;
+	  real_almost_one = sreal (1) - real_inv_br_prob_base;
 	}
 
       mark_dfs_back_edges ();
@@ -2910,7 +2908,7 @@ estimate_bb_frequencies (bool force)
 
 	  FOR_EACH_EDGE (e, ei, bb->succs)
 	    {
-	      EDGE_INFO (e)->back_edge_prob = sreal (e->probability, 0);
+	      EDGE_INFO (e)->back_edge_prob = e->probability;
 	      EDGE_INFO (e)->back_edge_prob *= real_inv_br_prob_base;
 	    }
 	}
@@ -2919,7 +2917,7 @@ estimate_bb_frequencies (bool force)
          to outermost to examine frequencies for back edges.  */
       estimate_loops ();
 
-      freq_max = real_zero;
+      freq_max = 0;
       FOR_EACH_BB_FN (bb, cfun)
 	if (freq_max < BLOCK_INFO (bb)->frequency)
 	  freq_max = BLOCK_INFO (bb)->frequency;
diff --git a/gcc/sreal.c b/gcc/sreal.c
index 3f5456a..0337f9e 100644
--- a/gcc/sreal.c
+++ b/gcc/sreal.c
@@ -1,4 +1,4 @@
-/* Simple data type for positive real numbers for the GNU compiler.
+/* Simple data type for real numbers for the GNU compiler.
    Copyright (C) 2002-2014 Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License
 along with GCC; see the file COPYING3.  If not see
 <http://www.gnu.org/licenses/>.  */
 
-/* This library supports positive real numbers and 0;
+/* This library supports real numbers;
    inf and nan are NOT supported.
    It is written to be simple and fast.
 
@@ -82,12 +82,12 @@ debug (sreal *ptr)
 void
 sreal::shift_right (int s)
 {
-  gcc_assert (s > 0);
-  gcc_assert (s <= SREAL_BITS);
+  gcc_checking_assert (s > 0);
+  gcc_checking_assert (s <= SREAL_BITS);
   /* Exponent should never be so large because shift_right is used only by
      sreal_add and sreal_sub ant thus the number cannot be shifted out from
      exponent range.  */
-  gcc_assert (m_exp + s <= SREAL_MAX_EXP);
+  gcc_checking_assert (m_exp + s <= SREAL_MAX_EXP);
 
   m_exp += s;
 
@@ -102,6 +102,7 @@ sreal::normalize ()
 {
   if (m_sig == 0)
     {
+      m_negative = 0;
       m_exp = -SREAL_MAX_EXP;
     }
   else if (m_sig < SREAL_MIN_SIG)
@@ -153,15 +154,17 @@ sreal::normalize ()
 int64_t
 sreal::to_int () const
 {
+  int64_t sign = m_negative ? -1 : 1;
+
   if (m_exp <= -SREAL_BITS)
     return 0;
   if (m_exp >= SREAL_PART_BITS)
-    return INTTYPE_MAXIMUM (int64_t);
+    return sign * INTTYPE_MAXIMUM (int64_t);
   if (m_exp > 0)
-    return m_sig << m_exp;
+    return sign * (m_sig << m_exp);
   if (m_exp < 0)
-    return m_sig >> -m_exp;
-  return m_sig;
+    return sign * (m_sig >> -m_exp);
+  return sign * m_sig;
 }
 
 /* Return *this + other.  */
@@ -169,18 +172,40 @@ sreal::to_int () const
 sreal
 sreal::operator+ (const sreal &other) const
 {
-  int dexp;
-  sreal tmp, r;
-const sreal *a_p = this, *b_p = &other, *bb;
+  const sreal *a_p = this, *b_p = &other;
 
-  if (*a_p < *b_p)
+  if (a_p->m_negative && !b_p->m_negative)
+    std::swap (a_p, b_p);
+
+  /* a + -b => a - b.  */
+  if (!a_p->m_negative && b_p->m_negative)
     {
-      const sreal *swap;
-      swap = a_p;
-      a_p = b_p;
-      b_p = swap;
+      sreal tmp = -(*b_p);
+      if (*a_p < tmp)
+	return signedless_minus (tmp, *a_p, false);
+      else
+	return signedless_minus (*a_p, tmp, true);
     }
 
+  gcc_checking_assert (a_p->m_negative == b_p->m_negative);
+
+  sreal r = signedless_plus (*a_p, *b_p, a_p->m_negative);
+
+  return r;
+}
+
+sreal
+sreal::signedless_plus (const sreal &a, const sreal &b, bool negative)
+{
+  const sreal *bb;
+  sreal r, tmp;
+  int dexp;
+  const sreal *a_p = &a;
+  const sreal *b_p = &b;
+
+  if (*a_p < *b_p)
+    std::swap (a_p, b_p);
+
   dexp = a_p->m_exp - b_p->m_exp;
   r.m_exp = a_p->m_exp;
   if (dexp > SREAL_BITS)
@@ -200,6 +225,8 @@ const sreal *a_p = this, *b_p = &other, *bb;
 
   r.m_sig = a_p->m_sig + bb->m_sig;
   r.normalize ();
+
+  r.m_negative = negative;
   return r;
 }
 
@@ -208,30 +235,60 @@ const sreal *a_p = this, *b_p = &other, *bb;
 sreal
 sreal::operator- (const sreal &other) const
 {
+  /* -a - b => -a + (-b).  */
+  if (m_negative && !other.m_negative)
+    return signedless_plus (*this, -other, true);
+
+  /* a - (-b) => a + b.  */
+  if (!m_negative && other.m_negative)
+    return signedless_plus (*this, -other, false);
+
+  gcc_checking_assert (m_negative == other.m_negative);
+
+  /* We want to substract a smaller number from bigger
+    for nonegative numbers.  */
+  if (!m_negative && *this < other)
+    return -signedless_minus (other, *this, true);
+
+  /* Example: -2 - (-3) => 3 - 2 */
+  if (m_negative && *this > other)
+    return signedless_minus (-other, -(*this), true);
+
+  sreal r = signedless_minus (*this, other, m_negative);
+
+  return r;
+}
+
+sreal
+sreal::signedless_minus (const sreal &a, const sreal &b, bool negative)
+{
   int dexp;
   sreal tmp, r;
   const sreal *bb;
+  const sreal *a_p = &a;
+  const sreal *b_p = &b;
 
-  gcc_assert (*this >= other);
+  dexp = a_p->m_exp - b_p->m_exp;
 
-  dexp = m_exp - other.m_exp;
-  r.m_exp = m_exp;
+  r.m_exp = a_p->m_exp;
   if (dexp > SREAL_BITS)
     {
-      r.m_sig = m_sig;
+      r.m_sig = a_p->m_sig;
       return r;
     }
   if (dexp == 0)
-    bb = &other;
+    bb = b_p;
   else
     {
-      tmp = other;
+      tmp = *b_p;
       tmp.shift_right (dexp);
       bb = &tmp;
     }
 
-  r.m_sig = m_sig - bb->m_sig;
+  r.m_sig = a_p->m_sig - bb->m_sig;
   r.normalize ();
+
+  r.m_negative = negative;
   return r;
 }
 
@@ -240,7 +297,7 @@ sreal::operator- (const sreal &other) const
 sreal
 sreal::operator* (const sreal &other) const
 {
-sreal r;
+  sreal r;
   if (m_sig < SREAL_MIN_SIG || other.m_sig < SREAL_MIN_SIG)
     {
       r.m_sig = 0;
@@ -252,6 +309,8 @@ sreal r;
       r.m_exp = m_exp + other.m_exp;
       r.normalize ();
     }
+
+  r.m_negative = m_negative ^ other.m_negative;
   return r;
 }
 
@@ -260,10 +319,11 @@ sreal r;
 sreal
 sreal::operator/ (const sreal &other) const
 {
-  gcc_assert (other.m_sig != 0);
-sreal r;
+  gcc_checking_assert (other.m_sig != 0);
+  sreal r;
   r.m_sig = (m_sig << SREAL_PART_BITS) / other.m_sig;
   r.m_exp = m_exp - other.m_exp - SREAL_PART_BITS;
+  r.m_negative = m_negative ^ other.m_negative;
   r.normalize ();
   return r;
 }
diff --git a/gcc/sreal.h b/gcc/sreal.h
index 461e28b..1362bf6 100644
--- a/gcc/sreal.h
+++ b/gcc/sreal.h
@@ -1,4 +1,4 @@
-/* Definitions for simple data type for positive real numbers.
+/* Definitions for simple data type for real numbers.
    Copyright (C) 2002-2014 Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -23,6 +23,8 @@ along with GCC; see the file COPYING3.  If not see
 /* SREAL_PART_BITS has to be an even number.  */
 #define SREAL_PART_BITS 32
 
+#define UINT64_BITS	64
+
 #define SREAL_MIN_SIG ((uint64_t) 1 << (SREAL_PART_BITS - 1))
 #define SREAL_MAX_SIG (((uint64_t) 1 << SREAL_PART_BITS) - 1)
 #define SREAL_MAX_EXP (INT_MAX / 4)
@@ -34,14 +36,23 @@ class sreal
 {
 public:
   /* Construct an uninitialized sreal.  */
-  sreal () : m_sig (-1), m_exp (-1) {}
+  sreal () : m_sig (-1), m_exp (-1), m_negative (0) {}
 
   /* Construct a sreal.  */
-  sreal (uint64_t sig, int exp) : m_sig (sig), m_exp (exp) { normalize (); }
+  sreal (int64_t sig, int exp = 0) : m_exp (exp)
+  {
+    m_negative = sig < 0;
+
+    if (sig < 0)
+      sig = -sig;
+
+    m_sig = (uint64_t) sig;
+
+    normalize ();
+  }
 
   void dump (FILE *) const;
   int64_t to_int () const;
-
   sreal operator+ (const sreal &other) const;
   sreal operator- (const sreal &other) const;
   sreal operator* (const sreal &other) const;
@@ -49,21 +60,64 @@ public:
 
   bool operator< (const sreal &other) const
   {
-    return m_exp < other.m_exp
+    if (m_negative != other.m_negative)
+      return m_negative > other.m_negative;
+
+    bool r = m_exp < other.m_exp
       || (m_exp == other.m_exp && m_sig < other.m_sig);
+
+    return m_negative ? !r : r;
   }
 
   bool operator== (const sreal &other) const
   {
-    return m_exp == other.m_exp && m_sig == other.m_sig;
+    return m_exp == other.m_exp && m_sig == other.m_sig
+		    && m_negative == other.m_negative;
+  }
+
+  sreal operator- () const
+  {
+    if (m_sig == 0)
+      return *this;
+
+    sreal tmp = *this;
+    tmp.m_negative = !tmp.m_negative;
+
+    return tmp;
+  }
+
+  sreal shift (int sig) const
+  {
+    sreal tmp = *this;
+    tmp.m_sig += sig;
+
+    return tmp;
+  }
+
+  /* Global minimum sreal can hold.  */
+  inline static sreal min ()
+  {
+    static sreal min = sreal (-SREAL_MAX_SIG, SREAL_MAX_EXP);
+    return min;
+  }
+
+  /* Global minimum sreal can hold.  */
+  inline static sreal max ()
+  {
+    static sreal max = sreal (SREAL_MAX_SIG, SREAL_MAX_EXP);
+    return max;
   }
 
 private:
   void normalize ();
   void shift_right (int amount);
 
-  uint64_t m_sig;		/* Significant.  */
+  static sreal signedless_plus (const sreal &a, const sreal &b, bool negative);
+  static sreal signedless_minus (const sreal &a, const sreal &b, bool negative);
+
+  uint64_t m_sig;			/* Significant.  */
   signed int m_exp;			/* Exponent.  */
+  bool m_negative;			/* Negative sign.  */
 };
 
 extern void debug (sreal &ref);
@@ -76,12 +130,12 @@ inline sreal &operator+= (sreal &a, const sreal &b)
 
 inline sreal &operator-= (sreal &a, const sreal &b)
 {
-return a = a - b;
+  return a = a - b;
 }
 
 inline sreal &operator/= (sreal &a, const sreal &b)
 {
-return a = a / b;
+  return a = a / b;
 }
 
 inline sreal &operator*= (sreal &a, const sreal &b)
@@ -109,4 +163,14 @@ inline bool operator>= (const sreal &a, const sreal &b)
   return a == b || a > b;
 }
 
+inline sreal operator<< (const sreal &a, int exp)
+{
+  return a.shift (exp);
+}
+
+inline sreal operator>> (const sreal &a, int exp)
+{
+  return a.shift (-exp);
+}
+
 #endif