base/dispatch.c, base/dispatch.h: Add proper detection for AVX2.

[catacomb] / base / dispatch-x86ish.S

diff --git a/base/dispatch-x86ish.S b/base/dispatch-x86ish.S
index 57d8d32..9510f96 100644 (file)
--- a/base/dispatch-x86ish.S
+++ b/base/dispatch-x86ish.S
@@ -155,6 +155,39 @@ FUNC(dispatch_x86ish_xmmregisters_p)
 ENDFUNC
 
 ///--------------------------------------------------------------------------
+/// Checking extended control registers.
+
+FUNC(dispatch_x86ish_xgetbv)
+       // Call with two arguments: a pointer Z_OUT to 8 bytes of output space, and
+       // a 32-bit integer C.  Read the 64-bit value of XCR(C), and store it
+       // at Z_OUT.
+
+#if CPUFAM_X86
+#  define Z_OUT edi
+       mov     edi, [esp + 4]
+       mov     ecx, [esp + 8]
+#endif
+#if CPUFAM_AMD64 && ABI_SYSV
+#  define Z_OUT rdi
+       mov     ecx, esi
+#endif
+#if CPUFAM_AMD64 && ABI_WIN
+#  define Z_OUT r8
+       mov     r8, rcx
+       mov     ecx, edx
+#endif
+  endprologue
+
+       xgetbv
+       mov     [Z_OUT + 0], eax
+       mov     [Z_OUT + 4], edx
+
+       ret
+
+#undef Z_OUT
+ENDFUNC
+
+///--------------------------------------------------------------------------
 /// Checking `rdrand'.
 
 FUNC(dispatch_x86ish_rdrand)