Another attempt at fixing the i686-mingw32-RA-on-linux buildbot.

[oota-llvm.git] / lib / Support / BlockFrequency.cpp

diff --git a/lib/Support/BlockFrequency.cpp b/lib/Support/BlockFrequency.cpp
index 6e4d6b1b33c016f655bb144e06459bb8d5f82eda..e7f3e1764c52d3a6131f022b081227b2f0887f06 100644 (file)
--- a/lib/Support/BlockFrequency.cpp
+++ b/lib/Support/BlockFrequency.cpp
@@ -11,103 +11,35 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Support/BranchProbability.h"
 #include "llvm/Support/BlockFrequency.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
 
 using namespace llvm;
 
-/// Multiply FREQ by N and store result in W array.
-static void mult96bit(uint64_t freq, uint32_t N, uint64_t W[2]) {
-  uint64_t u0 = freq & UINT32_MAX;
-  uint64_t u1 = freq >> 32;
-
-  // Represent 96-bit value as w[2]:w[1]:w[0];
-  uint32_t w[3] = { 0, 0, 0 };
-
-  uint64_t t = u0 * N;
-  uint64_t k = t >> 32;
-  w[0] = t;
-  t = u1 * N + k;
-  w[1] = t;
-  w[2] = t >> 32;
-
-  // W[1] - higher bits.
-  // W[0] - lower bits.
-  W[0] = w[0] + ((uint64_t) w[1] << 32);
-  W[1] = w[2];
-}
-
-
-/// Divide 96-bit value stored in W array by D.
-/// Return 64-bit quotient, saturated to UINT64_MAX on overflow.
-static uint64_t div96bit(uint64_t W[2], uint32_t D) {
-  uint64_t y = W[0];
-  uint64_t x = W[1];
-  unsigned i;
-
-  // This long division algorithm automatically saturates on overflow.
-  for (i = 0; i < 64 && x; ++i) {
-    uint32_t t = (int)x >> 31;
-    x = (x << 1) | (y >> 63);
-    y = y << 1;
-    if ((x | t) >= D) {
-      x -= D;
-      ++y;
-    }
-  }
-
-  return y << (64 - i);
-}
-
-
-void BlockFrequency::scale(uint32_t N, uint32_t D) {
-  assert(D != 0 && "Division by zero");
-
-  // Calculate Frequency * N.
-  uint64_t MulLo = (Frequency & UINT32_MAX) * N;
-  uint64_t MulHi = (Frequency >> 32) * N;
-  uint64_t MulRes = (MulHi << 32) + MulLo;
-
-  // If the product fits in 64 bits, just use built-in division.
-  if (MulHi <= UINT32_MAX && MulRes <= MulLo) {
-    Frequency = MulRes / D;
-    return;
-  }
-
-  // Product overflowed, use 96-bit operations.
-  // 96-bit value represented as W[1]:W[0].
-  uint64_t W[2];
-  mult96bit(Frequency, N, W);
-  Frequency = div96bit(W, D);
-  return;
-}
-
-BlockFrequency &BlockFrequency::operator*=(const BranchProbability &Prob) {
-  scale(Prob.getNumerator(), Prob.getDenominator());
+BlockFrequency &BlockFrequency::operator*=(BranchProbability Prob) {
+  Frequency = Prob.scale(Frequency);
   return *this;
 }
 
-const BlockFrequency
-BlockFrequency::operator*(const BranchProbability &Prob) const {
+BlockFrequency BlockFrequency::operator*(BranchProbability Prob) const {
   BlockFrequency Freq(Frequency);
   Freq *= Prob;
   return Freq;
 }
 
-BlockFrequency &BlockFrequency::operator/=(const BranchProbability &Prob) {
-  scale(Prob.getDenominator(), Prob.getNumerator());
+BlockFrequency &BlockFrequency::operator/=(BranchProbability Prob) {
+  Frequency = Prob.scaleByInverse(Frequency);
   return *this;
 }
 
-BlockFrequency BlockFrequency::operator/(const BranchProbability &Prob) const {
+BlockFrequency BlockFrequency::operator/(BranchProbability Prob) const {
   BlockFrequency Freq(Frequency);
   Freq /= Prob;
   return Freq;
 }
 
-BlockFrequency &BlockFrequency::operator+=(const BlockFrequency &Freq) {
+BlockFrequency &BlockFrequency::operator+=(BlockFrequency Freq) {
   uint64_t Before = Freq.Frequency;
   Frequency += Freq.Frequency;
 
@@ -118,31 +50,35 @@ BlockFrequency &BlockFrequency::operator+=(const BlockFrequency &Freq) {
   return *this;
 }
 
-const BlockFrequency
-BlockFrequency::operator+(const BlockFrequency &Prob) const {
-  BlockFrequency Freq(Frequency);
-  Freq += Prob;
-  return Freq;
+BlockFrequency BlockFrequency::operator+(BlockFrequency Freq) const {
+  BlockFrequency NewFreq(Frequency);
+  NewFreq += Freq;
+  return NewFreq;
 }
 
-void BlockFrequency::print(raw_ostream &OS) const {
-  // Convert fixed-point number to decimal.
-  OS << Frequency / getEntryFrequency() << ".";
-  uint64_t Rem = Frequency % getEntryFrequency();
-  uint64_t Eps = 1;
-  do {
-    Rem *= 10;
-    Eps *= 10;
-    OS << Rem / getEntryFrequency();
-    Rem = Rem % getEntryFrequency();
-  } while (Rem >= Eps/2);
+BlockFrequency &BlockFrequency::operator-=(BlockFrequency Freq) {
+  // If underflow, set frequency to 0.
+  if (Frequency <= Freq.Frequency)
+    Frequency = 0;
+  else
+    Frequency -= Freq.Frequency;
+  return *this;
 }
 
-namespace llvm {
-
-raw_ostream &operator<<(raw_ostream &OS, const BlockFrequency &Freq) {
-  Freq.print(OS);
-  return OS;
+BlockFrequency BlockFrequency::operator-(BlockFrequency Freq) const {
+  BlockFrequency NewFreq(Frequency);
+  NewFreq -= Freq;
+  return NewFreq;
 }
 
+BlockFrequency &BlockFrequency::operator>>=(const unsigned count) {
+  // Frequency can never be 0 by design.
+  assert(Frequency != 0);
+
+  // Shift right by count.
+  Frequency >>= count;
+
+  // Saturate to 1 if we are 0.
+  Frequency |= Frequency == 0;
+  return *this;
 }