Add a test case for testing ffs libcall conversion to constant

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22028 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/SimplifyLibCalls/FFS.ll

@@ -0,0 +1,23 @@
+; Test that the ToAsciiOptimizer works correctly
+; RUN: llvm-as < %s | opt -simplify-libcalls | llvm-dis | not grep 'call.*%ffs'
+
+declare int %ffs(int)
+declare int %ffsl(int)
+declare int %ffsll(long)
+
+implementation   ; Functions:
+
+int %main () {
+  %val1 = call int %ffs(int 1)
+  %val2 = call int %ffs(int 2048)
+  %val3 = call int %ffsl(int 65536)
+  %val4 = call int %ffsll(long 1024)
+  %val5 = call int %ffsll(long 17179869184)
+  %val6 = call int %ffsll(long 1152921504606846976)
+  %rslt1 = add int %val1, %val2
+  %rslt2 = add int %val3, %val4
+  %rslt3 = add int %val5, %val6
+  %rslt4 = add int %rslt1, %rslt2
+  %rslt5 = add int %rslt4, %rslt3
+  ret int %rslt5
+}