[newlib-cygwin] fhandler_proc.cc(format_proc_cpuinfo): fix cpuid level count

[Ken Brown]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=74aa6e3cdb167bdbfa02d5781e9efb154a15bcdb

commit 74aa6e3cdb167bdbfa02d5781e9efb154a15bcdb
Author: Brian Inglis <Brian.Inglis@SystematicSW.ab.ca>
Date:   Mon Oct 7 10:22:59 2019 -0600

    fhandler_proc.cc(format_proc_cpuinfo): fix cpuid level count
    
    Fix cpuid level count as number of non-zero leafs excluding sub-leafs.

Diff:
---
 winsup/cygwin/fhandler_proc.cc | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/winsup/cygwin/fhandler_proc.cc b/winsup/cygwin/fhandler_proc.cc
index 13cc368..78518ba 100644
--- a/winsup/cygwin/fhandler_proc.cc
+++ b/winsup/cygwin/fhandler_proc.cc
@@ -927,13 +927,30 @@ format_proc_cpuinfo (void *, char *&destbuf)
 
 	}
 
+      /* level is number of non-zero leafs exc. sub-leafs */
+      int level = maxf + 1 + (maxe & 0x7fffffff) + 1;
+
+      for (uint32_t l = maxe; 0x80000001 < l; --l)
+        {
+	  uint32_t a, b, c, d;
+	  cpuid (&a, &b, &c, &d, l);
+	  if (!(a | b | c | d))	--level;
+        }
+
+      for (uint32_t l = maxf; 1 < l; --l)
+        {
+	  uint32_t a, b, c, d;
+	  cpuid (&a, &b, &c, &d, l);
+	  if (!(a | b | c | d))	--level;
+        }
+
       bufptr += __small_sprintf (bufptr, "fpu\t\t: %s\n"
 					 "fpu_exception\t: %s\n"
 					 "cpuid level\t: %d\n"
 					 "wp\t\t: yes\n",
 				 (features1 & (1 << 0)) ? "yes" : "no",
 				 (features1 & (1 << 0)) ? "yes" : "no",
-				 maxf);
+				 level);
       print ("flags\t\t:");
       if (features1 & (1 << 0))
 	print (" fpu");