[APInt] Don't initialize VAL to 0 in APInt constructors. Push it down to the initSlow...

I'm not sure if zeroing VAL before writing pVal is really necessary, but at least one other place did it in code.

But by taking the store out of line, this reduces the opt binary by about 20k on my local x86-64 build.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298233 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/ADT/APInt.h b/include/llvm/ADT/APInt.h
index 8d8c898a053411ad1bc63c47f432d7f8b3111405..382a19e5d808e372a66f57dd5910f681b457ae16 100644 (file)
--- a/include/llvm/ADT/APInt.h
+++ b/include/llvm/ADT/APInt.h
@@ -232,7 +232,7 @@ public:
   /// \param val the initial value of the APInt
   /// \param isSigned how to treat signedness of val
   APInt(unsigned numBits, uint64_t val, bool isSigned = false)
-      : BitWidth(numBits), VAL(0) {
+      : BitWidth(numBits) {
     assert(BitWidth && "bitwidth too small");
     if (isSingleWord()) {
       VAL = val;
@@ -275,7 +275,7 @@ public:
 
   /// Simply makes *this a copy of that.
   /// @brief Copy Constructor.
-  APInt(const APInt &that) : BitWidth(that.BitWidth), VAL(0) {
+  APInt(const APInt &that) : BitWidth(that.BitWidth) {
     if (isSingleWord())
       VAL = that.VAL;
     else

diff --git a/lib/Support/APInt.cpp b/lib/Support/APInt.cpp
index d65dffec8c047d5bb51dce343a0c0192c3cb7342..58fa2f53690ac8b89bd730d2a1c77108f3634e96 100644 (file)
--- a/lib/Support/APInt.cpp
+++ b/lib/Support/APInt.cpp
@@ -76,6 +76,7 @@ inline static unsigned getDigit(char cdigit, uint8_t radix) {
 
 
 void APInt::initSlowCase(uint64_t val, bool isSigned) {
+  VAL = 0;
   pVal = getClearedMemory(getNumWords());
   pVal[0] = val;
   if (isSigned && int64_t(val) < 0)
@@ -85,6 +86,7 @@ void APInt::initSlowCase(uint64_t val, bool isSigned) {
 }
 
 void APInt::initSlowCase(const APInt& that) {
+  VAL = 0;
   pVal = getMemory(getNumWords());
   memcpy(pVal, that.pVal, getNumWords() * APINT_WORD_SIZE);
 }
@@ -96,6 +98,7 @@ void APInt::initFromArray(ArrayRef<uint64_t> bigVal) {
     VAL = bigVal[0];
   else {
     // Get memory, cleared to 0
+    VAL = 0;
     pVal = getClearedMemory(getNumWords());
     // Calculate the number of words to copy
     unsigned words = std::min<unsigned>(bigVal.size(), getNumWords());
@@ -107,12 +110,12 @@ void APInt::initFromArray(ArrayRef<uint64_t> bigVal) {
 }
 
 APInt::APInt(unsigned numBits, ArrayRef<uint64_t> bigVal)
-  : BitWidth(numBits), VAL(0) {
+  : BitWidth(numBits) {
   initFromArray(bigVal);
 }
 
 APInt::APInt(unsigned numBits, unsigned numWords, const uint64_t bigVal[])
-  : BitWidth(numBits), VAL(0) {
+  : BitWidth(numBits) {
   initFromArray(makeArrayRef(bigVal, numWords));
 }