[llvm-commits] CVS: llvm/lib/Target/PowerPC/README_ALTIVEC.txt

[Chris Lattner]

Changes in directory llvm/lib/Target/PowerPC:

README_ALTIVEC.txt updated: 1.25 -> 1.26
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Log message:

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Diffs of the changes:  (+10 -0)

 README_ALTIVEC.txt |   10 ++++++++++
 1 files changed, 10 insertions(+)


Index: llvm/lib/Target/PowerPC/README_ALTIVEC.txt
diff -u llvm/lib/Target/PowerPC/README_ALTIVEC.txt:1.25 llvm/lib/Target/PowerPC/README_ALTIVEC.txt:1.26
--- llvm/lib/Target/PowerPC/README_ALTIVEC.txt:1.25	Mon Apr 17 00:28:54 2006
+++ llvm/lib/Target/PowerPC/README_ALTIVEC.txt	Mon Apr 17 12:29:41 2006
@@ -110,3 +110,13 @@
 We can do an arbitrary non-constant value by using lvsr/perm/ste.
 
 //===----------------------------------------------------------------------===//
+
+If we want to tie instruction selection into the scheduler, we can do some
+constant formation with different instructions.  For example, we can generate
+"vsplti -1" with "vcmpequw R,R" and 1,1,1,1 with "vsubcuw R,R", both of which
+use different execution units, thus could help scheduling.
+
+This is probably only reasonable for a post-pass scheduler.
+
+//===----------------------------------------------------------------------===//
+