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authorZack Weinberg <zackw@panix.com>2017-06-08 15:39:03 -0400
committerZack Weinberg <zackw@panix.com>2017-06-08 15:39:03 -0400
commit5046dbb4a7eba5eccfd258f92f4735c9ffc8d069 (patch)
tree4470480d904b65cf14ca524f96f79eca818c3eaf /sysdeps/sparc/sparc32/dotmul.S
parent199fc19d3aaaf57944ef036e15904febe877fc93 (diff)
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Prepare for radical source tree reorganization.zack/build-layout-experiment
All top-level files and directories are moved into a temporary storage directory, REORG.TODO, except for files that will certainly still exist in their current form at top level when we're done (COPYING, COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which are moved to the new directory OldChangeLogs, instead), and the generated file INSTALL (which is just deleted; in the new order, there will be no generated files checked into version control).
Diffstat (limited to 'sysdeps/sparc/sparc32/dotmul.S')
-rw-r--r--sysdeps/sparc/sparc32/dotmul.S127
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diff --git a/sysdeps/sparc/sparc32/dotmul.S b/sysdeps/sparc/sparc32/dotmul.S
deleted file mode 100644
index d497ca672d..0000000000
--- a/sysdeps/sparc/sparc32/dotmul.S
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
- * 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 <sysdep.h>
-
-
-ENTRY(.mul)
- mov %o0, %y ! multiplier -> Y
- andncc %o0, 0xfff, %g0 ! test bits 12..31
- be LOC(mul_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
-
-LOC(mul_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
-
-END(.mul)