From b28e4264b5f9965ca5ab4f52ce6f4c9df00d4800 Mon Sep 17 00:00:00 2001
From: mliska <mliska@suse.cz>
Date: Fri, 21 Nov 2014 12:07:40 +0100
Subject: [PATCH 1/2] Negative numbers added for sreal class.
gcc/ChangeLog:
2014-11-13 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.h: Definition of new functions added.
---
gcc/predict.c | 30 ++++++++--------
gcc/sreal.c | 114 ++++++++++++++++++++++++++++++++++++++++++++--------------
gcc/sreal.h | 82 +++++++++++++++++++++++++++++++++++++-----
3 files changed, 174 insertions(+), 52 deletions(-)
@@ -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;
@@ -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;
}
@@ -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
--
2.1.2