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| -rw-r--r-- | lib/Target/PowerPC/README_ALTIVEC.txt | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/lib/Target/PowerPC/README_ALTIVEC.txt b/lib/Target/PowerPC/README_ALTIVEC.txt index 5d7ecd5691..2887b798b0 100644 --- a/lib/Target/PowerPC/README_ALTIVEC.txt +++ b/lib/Target/PowerPC/README_ALTIVEC.txt @@ -110,3 +110,13 @@ vec_ste(&destloc,0,vTemp); 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. + +//===----------------------------------------------------------------------===// + |