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Switch between POWER7 and POWER4 (GH #656) 

This is kind of tricky. We automatically drop from POWER7 to POWER4 if 7 is notavailable. However, if POWER7 is available the runtime test checks for HasAltivec(), and not HasPower7(), if the drop does not occur.
All of this goodness is happening on an old Apple G4 laptop with Gentoo. It is a "new toolchain on old hardware".
pull/748/head
Jeffrey Walton 2018-11-18 12:42:04 -05:00
parent 70473f0cab
commit e28b2e0f02
No known key found for this signature in database
GPG Key ID: B36AB348921B1838
1 changed files with 24 additions and 3 deletions
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27
chacha.cpp
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@ -25,6 +25,8 @@ extern void ChaCha_OperateKeystream_AVX2(const word32 *state, const byte* input,
#endif
#if (CRYPTOPP_ALTIVEC_AVAILABLE)
// ChaCha_OperateKeystream_POWER7 may be compiled with either -mcpu=power7 or
// -mcpu=power4. The makefile drops to POWER4 if POWER7 is not available.
extern void ChaCha_OperateKeystream_POWER7(const word32 *state, const byte* input, byte *output, unsigned int rounds);
#endif
@ -85,8 +87,7 @@ std::string ChaCha_Policy::AlgorithmProvider() const
if (HasPower7())
return "Power7";
else
#endif
#if (CRYPTOPP_ALTIVEC_AVAILABLE)
#elif (CRYPTOPP_ALTIVEC_AVAILABLE)
if (HasAltivec())
return "Altivec";
else
@ -250,11 +251,31 @@ void ChaCha_Policy::OperateKeystream(KeystreamOperation operation,
}
#endif
#if (CRYPTOPP_ALTIVEC_AVAILABLE)
#if (CRYPTOPP_POWER7_AVAILABLE)
if (HasPower7())
{
while (iterationCount >= 4 && MultiBlockSafe(4))
{
// ChaCha_OperateKeystream_POWER7 compiled with -mcpu=power7 and -DCRYPTOPP_POWER7_AVAILABLE
const bool xorInput = (operation & INPUT_NULL) != INPUT_NULL;
ChaCha_OperateKeystream_POWER7(m_state, xorInput ? input : NULLPTR, output, m_rounds);
// MultiBlockSafe avoids overflow on the counter words
m_state[12] += 4;
//if (m_state[12] < 4)
// m_state[13]++;
input += (!!xorInput)*4*BYTES_PER_ITERATION;
output += 4*BYTES_PER_ITERATION;
iterationCount -= 4;
}
}
#elif (CRYPTOPP_ALTIVEC_AVAILABLE)
if (HasAltivec())
{
while (iterationCount >= 4 && MultiBlockSafe(4))
{
// ChaCha_OperateKeystream_POWER7 compiled with -mcpu=power4 and -DCRYPTOPP_ALTIVEC_AVAILABLE
const bool xorInput = (operation & INPUT_NULL) != INPUT_NULL;
ChaCha_OperateKeystream_POWER7(m_state, xorInput ? input : NULLPTR, output, m_rounds);