* sysdeps/sparc/Makefile (routines): Reference `dotmul.S', not `mul.S', ...

diff --git a/sysdeps/sparc/dotmul.S b/sysdeps/sparc/dotmul.S
new file mode 100644 (file)
index 0000000..1c59a27
--- /dev/null
+++ b/sysdeps/sparc/dotmul.S
@@ -0,0 +1,123 @@
+/*
+ * 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.
+ */
+
+#include "DEFS.h"
+FUNC(.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