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Fix (and simplify) 48-bit byte swap. 

Get pos/neg infinity the correct way.

llvm-svn: 35223
This commit is contained in:
Jeff Cohen 2007-03-20 20:42:36 +00:00
parent b39885d23d
commit e06855e684
1 changed files with 8 additions and 9 deletions
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17
llvm/lib/Support/APInt.cpp
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@ -18,6 +18,7 @@
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
#include <math.h>
#include <limits>
#include <cstring>
#include <cstdlib>
#ifndef NDEBUG
@ -762,17 +763,15 @@ uint32_t APInt::countPopulation() const {
APInt APInt::byteSwap() const {
assert(BitWidth >= 16 && BitWidth % 16 == 0 && "Cannot byteswap!");
if (BitWidth == 16)
return APInt(BitWidth, ByteSwap_16(VAL));
return APInt(BitWidth, ByteSwap_16(uint16_t(VAL)));
else if (BitWidth == 32)
return APInt(BitWidth, ByteSwap_32(VAL));
return APInt(BitWidth, ByteSwap_32(uint32_t(VAL)));
else if (BitWidth == 48) {
uint64_t Tmp1 = ((VAL >> 32) << 16) | (VAL & 0xFFFF);
uint32_t Tmp1 = uint32_t(VAL >> 16);
Tmp1 = ByteSwap_32(Tmp1);
uint64_t Tmp2 = (VAL >> 16) & 0xFFFF;
uint16_t Tmp2 = uint16_t(VAL);
Tmp2 = ByteSwap_16(Tmp2);
return
APInt(BitWidth,
(Tmp1 & 0xff) | ((Tmp1<<16) & 0xffff00000000ULL) | (Tmp2 << 16));
return APInt(BitWidth, (uint64_t(Tmp2) << 32) | Tmp1);
} else if (BitWidth == 64)
return APInt(BitWidth, ByteSwap_64(VAL));
else {
@ -869,9 +868,9 @@ double APInt::roundToDouble(bool isSigned) const {
// Return infinity for exponent overflow
if (exp > 1023) {
if (!isSigned || !isNeg)
return double(1.0E300 * 1.0E300); // positive infinity
return std::numeric_limits<double>::infinity();
else
return double(-1.0E300 * 1.0E300); // negative infinity
return -std::numeric_limits<double>::infinity();
}
exp += 1023; // Increment for 1023 bias