// Regression: generated basic-block labels used to be named b1, b2, ... and
// `_entry`, which share one namespace with values in LLVM IR. A parameter
// named b1 therefore collided with block b1 and clang rejected the module
// with "'%b1' is not a basic block" at `br label %b1`. The labels are now
// dotted (bb.1, bb.entry) so no source identifier can reach them.
package main

import "fmt"

// A parameter named exactly like the old block labels, in a function with
// branches (which is what needs the generated blocks).
func pick(b1 byte, b2 byte) (r int32) {
	if b1 > b2 {
		r = int32(b1) - int32(b2)
	} else if b1 == b2 {
		r = 0
	} else {
		r = int32(b2) - int32(b1)
	}
	for i := byte(0); i < b1; i++ {
		r = r + int32(i)
	}
	return
}

// The entry label as a parameter name.
func entry(_entry int32) (r int32) {
	switch _entry {
	case 0:
		r = 10
	case 1:
		r = 20
	default:
		r = 30
	}
	return
}

func main() {
	if got := pick(3, 1); got != 2+0+1+2 {
		panic("pick(3,1)")
	}
	if got := pick(1, 4); got != 3 {
		panic("pick(1,4)")
	}
	if got := pick(2, 2); got != 1 {
		panic("pick(2,2)")
	}
	if entry(0)+entry(1)+entry(2) != 60 {
		panic("entry")
	}
	fmt.Println("ok")
}