Displaying 5 results from an estimated 5 matches for "avxbits".
Did you mean:
avx_bit
2013 Nov 22
2
[LLVMdev] [PATCH] Detect Haswell subarchitecture (i.e. using -march=native)
...anged, 10 insertions(+), 1 deletion(-)
diff --git a/lib/Support/Host.cpp b/lib/Support/Host.cpp
index 380df6b..2235456 100644
--- a/lib/Support/Host.cpp
+++ b/lib/Support/Host.cpp
@@ -138,6 +138,8 @@ std::string sys::getHostCPUName() {
// switch, then we have full AVX support.
const unsigned AVXBits = (1 << 27) | (1 << 28);
bool HasAVX = ((ECX & AVXBits) == AVXBits) && OSHasAVXSupport();
+ bool HasAVX2 = HasAVX && !GetX86CpuIDAndInfo(0x7, &EAX, &EBX, &ECX, &EDX) &&
+ (EBX & 0x20);
GetX86CpuIDAndInfo(0x80000001,...
2013 Sep 12
0
[LLVMdev] [PATCH] Detect Haswell subarchitecture (i.e. using -march=native)
Hi Adam,
> OK. I know the reason you cannot reproduce it, before posting
> the patch I've decided to check for AVX before checking AVX2,
> just not to cpuid AVX2 when we don't have AVX1 anyway.
I suspect it was also incompetence on my part. Given the differences
I'm seeing now I can't believe there'd be *no* difference in my tests
if I'd done them properly.
2013 Nov 23
0
[LLVMdev] [PATCH] Detect Haswell subarchitecture (i.e. using -march=native)
...+
+ unsigned MaxLeaf = EAX;
bool HasSSE3 = (ECX & 0x1);
bool HasSSE41 = (ECX & 0x80000);
// If CPUID indicates support for XSAVE, XRESTORE and AVX, and XGETBV
@@ -138,15 +215,12 @@ std::string sys::getHostCPUName() {
// switch, then we have full AVX support.
const unsigned AVXBits = (1 << 27) | (1 << 28);
bool HasAVX = ((ECX & AVXBits) == AVXBits) && OSHasAVXSupport();
+ bool HasAVX2 = HasAVX && MaxLeaf >= 0x7 &&
+ !GetX86CpuIDAndInfoEx(0x7, 0x0, &EAX, &EBX, &ECX, &EDX) &&
+...
2013 Sep 12
3
[LLVMdev] [PATCH] Detect Haswell subarchitecture (i.e. using -march=native)
> That's far more worrying to me than not being able to detect Haswell.
> I can't reproduce the problem here at the moment: both debug and
> release builds give identical assembly for Host.cpp.
OK. I know the reason you cannot reproduce it, before posting the patch I've decided to check for AVX before checking AVX2, just not to cpuid AVX2 when we don't have AVX1 anyway.
2013 Nov 23
2
[LLVMdev] [PATCH] Detect Haswell subarchitecture (i.e. using -march=native)
I agree with Tim, you need to implement a GetCpuIDAndInfoEx function in
Host.cpp and pass the correct value to ecx. Also you need to verify that 7
is a valid leaf because an invalid leaf is defined to return the highest
supported leaf on that processor. So if a processor supports say leaf 6 and
not leaf 7, then an access leaf 7 will return the data from leaf 6 causing
unrelated bits to be