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

[Chris Lattner]

Changes in directory llvm/lib/Target/PowerPC:

README.txt updated: 1.100 -> 1.101
---
Log message:

add note


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Diffs of the changes:  (+19 -0)

 README.txt |   19 +++++++++++++++++++
 1 files changed, 19 insertions(+)


Index: llvm/lib/Target/PowerPC/README.txt
diff -u llvm/lib/Target/PowerPC/README.txt:1.100 llvm/lib/Target/PowerPC/README.txt:1.101
--- llvm/lib/Target/PowerPC/README.txt:1.100	Fri Sep 22 00:01:56 2006
+++ llvm/lib/Target/PowerPC/README.txt	Fri Oct 13 15:20:58 2006
@@ -11,6 +11,25 @@
 
 ===-------------------------------------------------------------------------===
 
+Compile:
+
+void foo(int *P) {
+ if (P)  *P = 0;
+}
+
+into:
+
+_foo:
+        cmpwi cr0,r3,0
+        beqlr cr0
+        li r0,0
+        stw r0,0(r3)
+        blr
+
+This is effectively a simple form of predication.
+
+===-------------------------------------------------------------------------===
+
 Teach the .td file to pattern match PPC::BR_COND to appropriate bc variant, so
 we don't have to always run the branch selector for small functions.