llvm/test/Transforms/Inline/ptr-diff.ll

; RUN: opt -inline < %s -S -o - -inline-threshold=10 | FileCheck %s

target datalayout = "p:32:32-p1:64:64-p2:16:16-n16:32:64"

define i32 @outer1() {
; CHECK-LABEL: @outer1(
; CHECK-NOT: call i32
; CHECK: ret i32

  %ptr = alloca i32
  %ptr1 = getelementptr inbounds i32, i32* %ptr, i32 0
  %ptr2 = getelementptr inbounds i32, i32* %ptr, i32 42
  %result = call i32 @inner1(i32* %ptr1, i32* %ptr2)
  ret i32 %result
}

define i32 @inner1(i32* %begin, i32* %end) {
  call void @extern()
  %begin.i = ptrtoint i32* %begin to i32
  %end.i = ptrtoint i32* %end to i32
  %distance = sub i32 %end.i, %begin.i
  %icmp = icmp sle i32 %distance, 42
  br i1 %icmp, label %then, label %else

then:
  ret i32 3

else:
  %t = load i32, i32* %begin
  ret i32 %t
}

define i32 @outer2(i32* %ptr) {
; Test that an inbounds GEP disables this -- it isn't safe in general as
; wrapping changes the behavior of lessthan and greaterthan comparisons.
; CHECK-LABEL: @outer2(
; CHECK: call i32 @inner2
; CHECK: ret i32

  %ptr1 = getelementptr i32, i32* %ptr, i32 0
  %ptr2 = getelementptr i32, i32* %ptr, i32 42
  %result = call i32 @inner2(i32* %ptr1, i32* %ptr2)
  ret i32 %result
}

define i32 @inner2(i32* %begin, i32* %end) {
  call void @extern()
  %begin.i = ptrtoint i32* %begin to i32
  %end.i = ptrtoint i32* %end to i32
  %distance = sub i32 %end.i, %begin.i
  %icmp = icmp sle i32 %distance, 42
  br i1 %icmp, label %then, label %else

then:
  ret i32 3

else:
  %t = load i32, i32* %begin
  ret i32 %t
}

; The inttoptrs are free since it is a smaller integer to a larger
; pointer size
define i32 @inttoptr_free_cost(i32 %a, i32 %b, i32 %c) {
  call void @extern()
  %p1 = inttoptr i32 %a to i32 addrspace(1)*
  %p2 = inttoptr i32 %b to i32 addrspace(1)*
  %p3 = inttoptr i32 %c to i32 addrspace(1)*
  %t1 = load i32, i32 addrspace(1)* %p1
  %t2 = load i32, i32 addrspace(1)* %p2
  %t3 = load i32, i32 addrspace(1)* %p3
  %s = add i32 %t1, %t2
  %s1 = add i32 %s, %t3
  ret i32 %s1
}

define i32 @inttoptr_free_cost_user(i32 %begin, i32 %end) {
; CHECK-LABEL: @inttoptr_free_cost_user(
; CHECK-NOT: call i32
  %x = call i32 @inttoptr_free_cost(i32 %begin, i32 %end, i32 9)
  ret i32 %x
}

; The inttoptrs have a cost since it is a larger integer to a smaller
; pointer size
define i32 @inttoptr_cost_smaller_ptr(i32 %a, i32 %b, i32 %c) {
  call void @extern()
  %p1 = inttoptr i32 %a to i32 addrspace(2)*
  %p2 = inttoptr i32 %b to i32 addrspace(2)*
  %p3 = inttoptr i32 %c to i32 addrspace(2)*
  %t1 = load i32, i32 addrspace(2)* %p1
  %t2 = load i32, i32 addrspace(2)* %p2
  %t3 = load i32, i32 addrspace(2)* %p3
  %s = add i32 %t1, %t2
  %s1 = add i32 %s, %t3
  ret i32 %s1
}

define i32 @inttoptr_cost_smaller_ptr_user(i32 %begin, i32 %end) {
; CHECK-LABEL: @inttoptr_cost_smaller_ptr_user(
; CHECK: call i32
  %x = call i32 @inttoptr_cost_smaller_ptr(i32 %begin, i32 %end, i32 9)
  ret i32 %x
}

declare void @extern()