Fix TEA and XTE hand with IBM XL C/C++ compiler (GH #503)

It looks like Sun compilers had problems with the loop in the past, too. The Sun workarounds did not help with XL C/C++, however.

1 files changed, 12 insertions, 24 deletions

diff --git a/tea.cpp b/tea.cpp
index 3c0daa4c..7ca65367 100644
--- a/tea.cpp
+++ b/tea.cpp
@@ -19,11 +19,11 @@ void TEA::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const
 

 void TEA::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const

 {

-	word32 y, z;

+	word32 y, z, sum = 0;

 	Block::Get(inBlock)(y)(z);

 

-	word32 sum = 0;

-	while (sum != m_limit)

+	// http://github.com/weidai11/cryptopp/issues/503

+	while (*const_cast<volatile word32*>(&sum) != m_limit)

 	{

 		sum += DELTA;

 		y += ((z << 4) + m_k[0]) ^ (z + sum) ^ ((z >> 5) + m_k[1]);

@@ -35,11 +35,11 @@ void TEA::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byt
 

 void TEA::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const

 {

-	word32 y, z;

+	word32 y, z, sum = m_limit;

 	Block::Get(inBlock)(y)(z);

 

-	word32 sum = m_limit;

-	while (sum != 0)

+	// http://github.com/weidai11/cryptopp/issues/503

+	while (*const_cast<volatile word32*>(&sum) != 0)

 	{

 		z -= ((y << 4) + m_k[2]) ^ (y + sum) ^ ((y >> 5) + m_k[3]);

 		y -= ((z << 4) + m_k[0]) ^ (z + sum) ^ ((z >> 5) + m_k[1]);

@@ -59,17 +59,11 @@ void XTEA::Base::UncheckedSetKey(const byte *userKey, unsigned int length,  cons
 

 void XTEA::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const

 {

-	word32 y, z;

+	word32 y, z, sum = 0;

 	Block::Get(inBlock)(y)(z);

 

-#ifdef __SUNPRO_CC

-	// workaround needed on Sun Studio 12u1 Sun C++ 5.10 SunOS_i386 128229-02 2009/09/21

-	size_t sum = 0;

-	while ((sum&0xffffffff) != m_limit)

-#else

-	word32 sum = 0;

-	while (sum != m_limit)

-#endif

+	// http://github.com/weidai11/cryptopp/issues/503

+	while (*const_cast<volatile word32*>(&sum) != m_limit)

 	{

 		y += ((z<<4 ^ z>>5) + z) ^ (sum + m_k[sum&3]);

 		sum += DELTA;

@@ -81,17 +75,11 @@ void XTEA::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, by
 

 void XTEA::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const

 {

-	word32 y, z;

+	word32 y, z, sum = m_limit;

 	Block::Get(inBlock)(y)(z);

 

-#ifdef __SUNPRO_CC

-	// workaround needed on Sun Studio 12u1 Sun C++ 5.10 SunOS_i386 128229-02 2009/09/21

-	size_t sum = m_limit;

-	while ((sum&0xffffffff) != 0)

-#else

-	word32 sum = m_limit;

-	while (sum != 0)

-#endif

+	// http://github.com/weidai11/cryptopp/issues/503

+	while (*const_cast<volatile word32*>(&sum) != 0)

 	{

 		z -= ((y<<4 ^ y>>5) + y) ^ (sum + m_k[sum>>11 & 3]);

 		sum -= DELTA;