From: Fredrik Tolf <fredrik@dolda2000.com>
Date: Wed, 23 Jan 2019 15:43:07 +0000 (+0100)
Subject: loadcpu: Added SNB-optimized spinloop.
X-Git-Url: http://git.dolda2000.com/gitweb/?p=utils.git;a=commitdiff_plain;h=06282b33ce67d6918f6344c6536aa946cb06c344

loadcpu: Added SNB-optimized spinloop.
---

diff --git a/loadcpu.c b/loadcpu.c
index ca39f7f..68e0429 100644
--- a/loadcpu.c
+++ b/loadcpu.c
@@ -4,6 +4,31 @@
 #include <errno.h>
 #include <pthread.h>
 
+static void *spin_snb(void *uu)
+{
+    char __attribute__((aligned(32))) m[2][32];
+    
+    asm("vpxor %%xmm1, %%xmm1, %%xmm1;\n"
+	"vpxor %%xmm2, %%xmm2, %%xmm2;\n"
+	"0:\n"
+	"vmovaps (%0), %%ymm0;\n"
+	"vmovaps %%ymm1, (%1);\n"
+	"vaddps %%ymm1, %%ymm1, %%ymm2\n"
+	"vmulps %%ymm3, %%ymm3, %%ymm4\n"
+	"vmovaps (%0), %%ymm0;\n"
+	"vmovaps %%xmm1, (%1);\n"
+	"vaddps %%ymm1, %%ymm1, %%ymm2\n"
+	"vmulps %%ymm3, %%ymm3, %%ymm4\n"
+	"vmovaps (%0), %%ymm0;\n"
+	"vaddps %%ymm1, %%ymm1, %%ymm2\n"
+	"vmulps %%ymm3, %%ymm3, %%ymm4\n"
+	"jmp 0b;\n"
+	:
+	: "r" (&m[0]), "r" (&m[1])
+	: "rax", "rcx");
+    abort();
+}
+
 static void *spin(void *uu)
 {
     while(1) {