Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/arch/sparc/lib/mul.S b/arch/sparc/lib/mul.S
new file mode 100644
index 0000000..83dffbc
--- /dev/null
+++ b/arch/sparc/lib/mul.S
@@ -0,0 +1,135 @@
+/* $Id: mul.S,v 1.4 1996/09/30 02:22:32 davem Exp $
+ * mul.S: This routine was taken from glibc-1.09 and is covered
+ * by the GNU Library General Public License Version 2.
+ */
+
+/*
+ * Signed multiply, from Appendix E of the Sparc Version 8
+ * Architecture Manual.
+ */
+
+/*
+ * Returns %o0 * %o1 in %o1%o0 (i.e., %o1 holds the upper 32 bits of
+ * the 64-bit product).
+ *
+ * This code optimizes short (less than 13-bit) multiplies.
+ */
+
+ .globl .mul
+.mul:
+ mov %o0, %y ! multiplier -> Y
+ andncc %o0, 0xfff, %g0 ! test bits 12..31
+ be Lmul_shortway ! if zero, can do it the short way
+ andcc %g0, %g0, %o4 ! zero the partial product and clear N and V
+
+ /*
+ * Long multiply. 32 steps, followed by a final shift step.
+ */
+ mulscc %o4, %o1, %o4 ! 1
+ mulscc %o4, %o1, %o4 ! 2
+ mulscc %o4, %o1, %o4 ! 3
+ mulscc %o4, %o1, %o4 ! 4
+ mulscc %o4, %o1, %o4 ! 5
+ mulscc %o4, %o1, %o4 ! 6
+ mulscc %o4, %o1, %o4 ! 7
+ mulscc %o4, %o1, %o4 ! 8
+ mulscc %o4, %o1, %o4 ! 9
+ mulscc %o4, %o1, %o4 ! 10
+ mulscc %o4, %o1, %o4 ! 11
+ mulscc %o4, %o1, %o4 ! 12
+ mulscc %o4, %o1, %o4 ! 13
+ mulscc %o4, %o1, %o4 ! 14
+ mulscc %o4, %o1, %o4 ! 15
+ mulscc %o4, %o1, %o4 ! 16
+ mulscc %o4, %o1, %o4 ! 17
+ mulscc %o4, %o1, %o4 ! 18
+ mulscc %o4, %o1, %o4 ! 19
+ mulscc %o4, %o1, %o4 ! 20
+ mulscc %o4, %o1, %o4 ! 21
+ mulscc %o4, %o1, %o4 ! 22
+ mulscc %o4, %o1, %o4 ! 23
+ mulscc %o4, %o1, %o4 ! 24
+ mulscc %o4, %o1, %o4 ! 25
+ mulscc %o4, %o1, %o4 ! 26
+ mulscc %o4, %o1, %o4 ! 27
+ mulscc %o4, %o1, %o4 ! 28
+ mulscc %o4, %o1, %o4 ! 29
+ mulscc %o4, %o1, %o4 ! 30
+ mulscc %o4, %o1, %o4 ! 31
+ mulscc %o4, %o1, %o4 ! 32
+ mulscc %o4, %g0, %o4 ! final shift
+
+ ! If %o0 was negative, the result is
+ ! (%o0 * %o1) + (%o1 << 32))
+ ! We fix that here.
+
+#if 0
+ tst %o0
+ bge 1f
+ rd %y, %o0
+
+ ! %o0 was indeed negative; fix upper 32 bits of result by subtracting
+ ! %o1 (i.e., return %o4 - %o1 in %o1).
+ retl
+ sub %o4, %o1, %o1
+
+1:
+ retl
+ mov %o4, %o1
+#else
+ /* Faster code adapted from tege@sics.se's code for umul.S. */
+ sra %o0, 31, %o2 ! make mask from sign bit
+ and %o1, %o2, %o2 ! %o2 = 0 or %o1, depending on sign of %o0
+ rd %y, %o0 ! get lower half of product
+ retl
+ sub %o4, %o2, %o1 ! subtract compensation
+ ! and put upper half in place
+#endif
+
+Lmul_shortway:
+ /*
+ * Short multiply. 12 steps, followed by a final shift step.
+ * The resulting bits are off by 12 and (32-12) = 20 bit positions,
+ * but there is no problem with %o0 being negative (unlike above).
+ */
+ mulscc %o4, %o1, %o4 ! 1
+ mulscc %o4, %o1, %o4 ! 2
+ mulscc %o4, %o1, %o4 ! 3
+ mulscc %o4, %o1, %o4 ! 4
+ mulscc %o4, %o1, %o4 ! 5
+ mulscc %o4, %o1, %o4 ! 6
+ mulscc %o4, %o1, %o4 ! 7
+ mulscc %o4, %o1, %o4 ! 8
+ mulscc %o4, %o1, %o4 ! 9
+ mulscc %o4, %o1, %o4 ! 10
+ mulscc %o4, %o1, %o4 ! 11
+ mulscc %o4, %o1, %o4 ! 12
+ mulscc %o4, %g0, %o4 ! final shift
+
+ /*
+ * %o4 has 20 of the bits that should be in the low part of the
+ * result; %y has the bottom 12 (as %y's top 12). That is:
+ *
+ * %o4 %y
+ * +----------------+----------------+
+ * | -12- | -20- | -12- | -20- |
+ * +------(---------+------)---------+
+ * --hi-- ----low-part----
+ *
+ * The upper 12 bits of %o4 should be sign-extended to form the
+ * high part of the product (i.e., highpart = %o4 >> 20).
+ */
+
+ rd %y, %o5
+ sll %o4, 12, %o0 ! shift middle bits left 12
+ srl %o5, 20, %o5 ! shift low bits right 20, zero fill at left
+ or %o5, %o0, %o0 ! construct low part of result
+ retl
+ sra %o4, 20, %o1 ! ... and extract high part of result
+
+ .globl .mul_patch
+.mul_patch:
+ smul %o0, %o1, %o0
+ retl
+ rd %y, %o1
+ nop