How to run CoreCLR with the AVX support?

[AndreyAkinshin]

Let's consider the following method:

[MethodImpl(MethodImplOptions.NoInlining)]
public double Run()
{
    return Math.Sqrt(1);
}

I have the following asm code from Visual Studio 2015 RC (x64, useLegacyJit=0, Release mode):

        return Math.Sqrt(1);
00007FF94F9B4A50  vsqrtsd     xmm0,xmm0,mmword ptr [7FF94F9B4A60h]  
00007FF94F9B4A59  ret  

But if I run this method with CoreCLR (SET COMPLUS_JitDisasm=Run), I have the following log:

; Assembly listing for method Program:Run():double:this
; Emitting BLENDED_CODE for X64 CPU with SSE2
; optimized code
; rsp based frame
; partially interruptible
; Final local variable assignments
;
;* V00 this         [V00    ] (  0,   0  )     ref  ->  zero ref    this
;# V01 OutArgs      [V01    ] (  1,   1  )  lclBlk ( 0) [rsp+0x00]
;
; Lcl frame size = 0

G_M43239_IG01:

G_M43239_IG02:
       F20F510508000000     sqrtsd   xmm0, qword ptr [@RWD00]

G_M43239_IG03:
       C3                   ret

; Total bytes of code 9, prolog size 0 for method Program:Run():double:this
; ============================================================

But I want see a log with AVX support and the vsqrtsd instruction. How I can do it?

[BruceForstall]

@CarolEidt Is this something you fixed recently?

[CarolEidt]

In an odd coincidence, I have just today discovered that neither FEATURE_SIMD or FEATURE_AVX_SUPPORT are enabled for CoreCLR. I'm actually working on enabling it now. If you want to turn it on, you can add the following line to the CMakeLists.txt in the jit directory:
add_definitions(-FEATURE_AVX_SUPPORT)
but be forewarned that I've just starting looking at this, so I'm not sure what issues I may encounter (and I still need to track down how to enable that only for amd64).

[CarolEidt]

Fixed with PR dotnet/coreclr#981

[AndreyAkinshin]

Now it works, thanks!