tests/tut2.R

In doktorschiwago/Rllvm2: Interface to llvm for dynamically compiling native code.

# This the second example from the JIT tutorial in llvm-2.6
# and covers computing the GCD.

library(Rllvm)

InitializeNativeTarget()

mod = Module("test.gcd")

fun = Function("gcd", Int32Type, c(x = Int32Type, y = Int32Type), mod)
params = getParameters(fun)

b1 = Block(fun, "entry")
b.ret = Block(fun, "return")
b.false1 = Block(fun)
b.true2 = Block(fun)
b.false2 = Block(fun)

ir = IRBuilder(b1)

xeqy = createICmp(ir, ICMP_EQ, params$x, params$y)
createCondBr(ir, xeqy, b.ret, b.false1)

# So now implement the return.
setInsertPoint(ir, b.ret)
createReturn(ir, params$x)

setInsertPoint(ir, b.false1)
xlty = createICmp(ir, ICMP_SLT, params$x, params$y)
createCondBr(ir, xlty, b.true2, b.false2)


setInsertPoint(ir, b.true2)
ylessx = binOp(ir, Sub, params$y, params$x)
val = createCall(ir, fun, params$x, ylessx)
createReturn(ir, val)

setInsertPoint(ir, b.false2)
diff = binOp(ir, Sub, params$x, params$y)
val = createCall(ir, fun, params$y, diff)
createReturn(ir, val)


verifyModule(mod)
val = run(fun, 30L, 20L)
 run(fun, 3L, 9L)
 run(fun, 30L, 32L)
 run(fun, 30L, 31L)
 run(fun, 3000L, 30000L)

 run(fun, 3000, 30000)