Initial QSfera import

Server/vendor/github.com/pjbgf/sha1cd/sha1cdblock_amd64.go

@@ -0,0 +1,52 @@
+//go:build !noasm && gc && amd64 && !arm64
+// +build !noasm,gc,amd64,!arm64
+
+package sha1cd
+
+import (
+	"runtime"
+
+	"github.com/klauspost/cpuid/v2"
+	shared "github.com/pjbgf/sha1cd/internal"
+)
+
+var hasSHANI = (runtime.GOARCH == "amd64" &&
+	cpuid.CPU.Supports(cpuid.AVX) &&
+	cpuid.CPU.Supports(cpuid.SHA) &&
+	cpuid.CPU.Supports(cpuid.SSE3) &&
+	cpuid.CPU.Supports(cpuid.SSE4))
+
+// blockAMD64 hashes the message p into the current state in h.
+// Both m1 and cs are used to store intermediate results which are used by the collision detection logic.
+//
+//go:noescape
+func blockAMD64(h []uint32, p []byte, m1 []uint32, cs [][5]uint32)
+
+func block(dig *digest, p []byte) {
+	if forceGeneric || !hasSHANI {
+		blockGeneric(dig, p)
+		return
+	}
+
+	m1 := [shared.Rounds]uint32{}
+	cs := [shared.PreStepState][shared.WordBuffers]uint32{}
+
+	for len(p) >= shared.Chunk {
+		// The assembly code only supports processing a block at a time,
+		// so adjust the chunk accordingly.
+		chunk := p[:shared.Chunk]
+
+		blockAMD64(dig.h[:], chunk, m1[:], cs[:])
+		rectifyCompressionState(&m1, &cs)
+
+		col := checkCollision(&m1, &cs, &dig.h)
+		if col {
+			dig.col = true
+
+			blockAMD64(dig.h[:], chunk, m1[:], cs[:])
+			blockAMD64(dig.h[:], chunk, m1[:], cs[:])
+		}
+
+		p = p[shared.Chunk:]
+	}
+}