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authorcharles forsyth <charles.forsyth@gmail.com>2014-05-18 14:19:01 +0100
committercharles forsyth <charles.forsyth@gmail.com>2014-05-18 14:19:01 +0100
commit37e9221a5d1905cba45c96ac44dbe26d947bc4af (patch)
tree87bf6a76dc94bc638418883e0ca21afcfa2ad78f /lib9/setfcr-OpenBSD-386.c
parent7e479951464b9bb71e87aeef19d908e9fb9be494 (diff)
20140518-1419
Diffstat (limited to 'lib9/setfcr-OpenBSD-386.c')
-rw-r--r--lib9/setfcr-OpenBSD-386.c57
1 files changed, 57 insertions, 0 deletions
diff --git a/lib9/setfcr-OpenBSD-386.c b/lib9/setfcr-OpenBSD-386.c
new file mode 100644
index 00000000..c512f033
--- /dev/null
+++ b/lib9/setfcr-OpenBSD-386.c
@@ -0,0 +1,57 @@
+/*
+ * 386 fpu support
+ * Mimic Plan9 floating point support
+ */
+
+#include "lib9.h"
+
+
+void
+setfcr(ulong fcr)
+{
+ __asm__( "xorb $0x3f, %%al\n\t"
+ "pushw %%ax\n\t"
+ "fwait\n\t"
+ "fldcw (%%esp)\n\t"
+ "popw %%ax\n\t"
+ : /* no output */
+ : "al" (fcr)
+ );
+}
+
+ulong
+getfcr(void)
+{
+ ulong fcr = 0;
+
+ __asm__( "pushl %%eax\n\t"
+ "fwait\n\t"
+ "fstcw (%%esp)\n\t"
+ "popl %%eax\n\t"
+ "xorb $0x3f, %%al\n\t"
+ : "=a" (fcr)
+ : "eax" (fcr)
+ );
+ return fcr;
+}
+
+ulong
+getfsr(void)
+{
+ ulong fsr = -1;
+
+ __asm__( "fwait\n\t"
+ "fstsw (%%eax)\n\t"
+ "movl (%%eax), %%eax\n\t"
+ "andl $0xffff, %%eax\n\t"
+ : "=a" (fsr)
+ : "eax" (&fsr)
+ );
+ return fsr;
+}
+
+void
+setfsr(ulong fsr)
+{
+ __asm__("fclex\n\t");
+}