Add testcase for legalizing ISD::CTTZ efficiently. On PPC, ctlz(int) is

now codegen'd as this:

        addi r2, r3, -1
        andc r2, r2, r3
        cntlzw r2, r2
        subfic r3, r2, 32
        blr

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21881 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/CodeGen/PowerPC/cttz.ll b/test/CodeGen/PowerPC/cttz.ll
new file mode 100644 (file)
index 0000000..f860456
--- /dev/null
+++ b/test/CodeGen/PowerPC/cttz.ll
@@ -0,0 +1,12 @@
+; Make sure this testcase does not use ctpop
+; RUN: llvm-as < %s | llc -march=ppc32 | grep -i 'cntlzw'
+
+declare int %llvm.cttz(int)
+
+implementation   ; Functions:
+
+int %bar(int %x) {
+entry:
+       %tmp.1 = call int %llvm.cttz( int %x ) 
+       ret int %tmp.1
+}