auto import from //depot/cupcake/@135843
diff --git a/libm/i387/s_trunc.S b/libm/i387/s_trunc.S
new file mode 100644
index 0000000..1d78e1c
--- /dev/null
+++ b/libm/i387/s_trunc.S
@@ -0,0 +1,26 @@
+/*
+ * Based on code written by J.T. Conklin <jtc@NetBSD.org>.
+ * Public domain.
+ */
+
+#include <machine/asm.h>
+__FBSDID("$FreeBSD: src/lib/msun/i387/s_trunc.S,v 1.1 2005/04/16 21:12:55 das Exp $")
+
+ENTRY(trunc)
+ pushl %ebp
+ movl %esp,%ebp
+ subl $8,%esp
+
+ fstcw -4(%ebp) /* store fpu control word */
+ movw -4(%ebp),%dx
+ orw $0x0c00,%dx /* round towards -oo */
+ movw %dx,-8(%ebp)
+ fldcw -8(%ebp) /* load modfied control word */
+
+ fldl 8(%ebp) /* round */
+ frndint
+
+ fldcw -4(%ebp) /* restore original control word */
+
+ leave
+ ret