Changes in directory llvm/lib/Target/PowerPC:
README.txt updated: 1.43 -> 1.44
---
Log message:
transfer some notes from my email to somewhere useful.
---
Diffs of the changes: (+26 -0)
README.txt | 26 ++++++++++++++++++++++++++
1 files changed, 26 insertions(+)
Index: llvm/lib/Target/PowerPC/README.txt
diff -u llvm/lib/Target/PowerPC/README.txt:1.43
llvm/lib/Target/PowerPC/README.txt:1.44
--- llvm/lib/Target/PowerPC/README.txt:1.43 Fri Jan 13 19:24:22 2006
+++ llvm/lib/Target/PowerPC/README.txt Mon Jan 16 11:53:00 2006
@@ -225,3 +225,29 @@
void xxx(struct foo F);
void bar() { struct foo R = { 1.0, 2.0 }; xxx(R); }
+===-------------------------------------------------------------------------===
+
+For this:
+
+int h(int i, int j, int k) {
+ return (i==0||j==0||k == 0);
+}
+
+We currently emit this:
+
+_h:
+ cntlzw r2, r3
+ cntlzw r3, r4
+ cntlzw r4, r5
+ srwi r2, r2, 5
+ srwi r3, r3, 5
+ srwi r4, r4, 5
+ or r2, r3, r2
+ or r3, r2, r4
+ blr
+
+The ctlz/shift instructions are created by the isel, so the dag combiner
doesn't
+have a chance to pull the shifts through the or's (eliminating two
+instructions). SETCC nodes should be custom lowered in this case, not expanded
+by the isel.
+
_______________________________________________
llvm-commits mailing list
llvm-commits@cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
