<html> <head> <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1"> </head> <body bgcolor="#FFFFFF" text="#000000"> While I was trying to understand how cpu features detection works, I noticed that every was coherent except for the TSC ( <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1"> Time Stamp Counter). I found many pages on the net that suggest that the right value for the corresponding shift would be 4 and not 8. Even the commented bitfields that represent the bit flag for each cpu feature seems to suggest that. From 17adc106ce2718343dd17750c928137441ef3086 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Maxence=20Le=20Dor=C3=A9?= <a class="moz-txt-link-rfc2396E" href="mailto:maxence.ledore@gmail.com"><maxence.ledore@gmail.com></a> Date: Thu, 7 Mar 2013 02:30:03 +0100 Subject: [PATCH] util: fix wrong shift val for a cpu feature detect --- src/gallium/auxiliary/util/u_cpu_detect.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/gallium/auxiliary/util/u_cpu_detect.c b/src/gallium/auxiliary/util/u_cpu_detect.c index d7f0be4..0328051 100644 --- a/src/gallium/auxiliary/util/u_cpu_detect.c +++ b/src/gallium/auxiliary/util/u_cpu_detect.c @@ -270,7 +270,7 @@ util_cpu_detect(void) util_cpu_caps.x86_cpu_type = 8 + ((regs2[0] >> 20) & 255); /* use extended family (P4, IA64) */ /* general feature flags */ - util_cpu_caps.has_tsc = (regs2[3] >> 8) & 1; /* 0x0000010 */ + util_cpu_caps.has_tsc = (regs2[3] >> 4) & 1; /* 0x0000010 */ util_cpu_caps.has_mmx = (regs2[3] >> 23) & 1; /* 0x0800000 */ util_cpu_caps.has_sse = (regs2[3] >> 25) & 1; /* 0x2000000 */ util_cpu_caps.has_sse2 = (regs2[3] >> 26) & 1; /* 0x4000000 */ -- 1.7.9.5 </body> </html>