When the data type is single-precision real or single-precision complex,
converting it to double precision does not prevent overflow (as exposed in LAPACK tests).
The only solution is to follow C's approach: find the maximum value in the
array and divide each element by that maximum to avoid this issue

Fixed the error when the stride is zero

Do not check whether the input parameters c and s are zero,
as this may cause errors with special values (same as scal).
Although OpenBLAS's own test suite doesn't catch this, it will
cause LAPACK test cases to fail.

Fixed incorrect store operation

Signed-off-by: gxw <guxiwei-hf@loongson.cn>

Fixed index retrieval issue when there are
identical maximum absolute values

Signed-off-by: Hao Chen <chenhao@loongson.cn>
Signed-off-by: gxw <guxiwei-hf@loongson.cn>

Fixed incorrect register usage in instructions

Signed-off-by: gxw <guxiwei-hf@loongson.cn>

Fixed register zeroing operation

Signed-off-by: Hao Chen <chenhao@loongson.cn>
Signed-off-by: gxw <guxiwei-hf@loongson.cn>

Further rearranged the rotm kernel for the different architectures.

Signed-off-by: tingbo.liao <tingbo.liao@starfivetech.com>

"fmov.d $f2, $f4" leaves all the bits higher than the 63-th bit
unpredictable but it's obvious that the following code uses the value of
those high bits.  We actually want to replicate the lower 64 bits here,
so we should use xvreplve0.d instead.

LA464 (Loongson 3[A-Z]-5000) happens to replicate them for us due to
some uarch internal details so the issue was not detected, but for LA664
(Loongson 3[A-Z]-6000) and future uarch we need to do things correctly
or we end up getting a lot of test failures.

Closes: https://bbs.aosc.io/t/topic/302
Signed-off-by: Xi Ruoyao <xry111@xry111.site>

LoongArch64: Enable cmake cross-compilation

Use microarchitecture name instead of meaningless strings to name the core,
the legacy core is still retained.
1. Rename LOONGSONGENERIC to LA64_GENERIC
2. Rename LOONGSON3R5 to LA464
3. Rename LOONGSON2K1000 to LA264

Loongarch64: Improving the Performance and Stability of dgemm

Initialize the registers to prevent sporadic errors.

Optimized sgemv and dgemv kernel LSX for LoongArch