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matrix: work around instruction selection bug in clang

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This commit is contained in:
Danny Robson 2017-10-10 14:09:07 +11:00
parent 720a45deb8
commit 2e5d69c095
2 changed files with 25 additions and 24 deletions
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26
matrix.hpp
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@ -216,7 +216,31 @@ namespace util {
>
constexpr
matrix<R1,C2,T>
operator* (const matrix<R1,C1,T>&, const matrix<R2,C2,T>&);
operator* (const matrix<R1,C1,T> &a, const matrix<R2,C2,T> &b) noexcept
{
static_assert (R2 == C1);
matrix<R1,C2,T> res {0};
// TODO: iterating over r,c rather than c,r will cause an ICE with
// clang#xxxx: 'X86 DAG->DAG Instruction Selection'.
//
// this is likely related to gold and LTO support. for the time being
// we switch the orders because it appears to confuse the optimiser
// sufficiently. :(
for (size_t c = 0; c < C2; ++c) {
for (size_t r = 0; r < R1; ++r) {
T accum{0};
for (size_t i = 0; i < R2; ++i)
accum += a[r][i] * b[i][c];
res[r][c] = accum;
}
}
return res;
}
//-------------------------------------------------------------------------

23
matrix.ipp
View File

@ -99,29 +99,6 @@ MATRIX_SCALAR_OP(-)
#undef MATRIX_SCALAR_OP
///////////////////////////////////////////////////////////////////////////////
template <
std::size_t R1, std::size_t C1,
std::size_t R2, std::size_t C2,
typename T
>
constexpr
util::matrix<R1,C2,T>
util::operator* (const matrix<R1,C1,T> &a, const matrix<R2,C2,T> &b)
{
static_assert (R2 == C1);
matrix<R1,C2,T> res {0};
for (size_t r = 0; r < R1; ++r)
for (size_t c = 0; c < C2; ++c)
for (size_t i = 0; i < R2; ++i)
res[r][c] += a[r][i] * b[i][c];
return res;
}
///////////////////////////////////////////////////////////////////////////////
template <size_t Rows, size_t Cols, typename T>
constexpr