1 ; RUN: opt < %s -instsimplify -S | FileCheck %s 2 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" 3 target triple = "x86_64-unknown-linux-gnu" 4 5 define i64 @ptrdiff1(i8* %ptr) { 6 ; CHECK: @ptrdiff1 7 ; CHECK-NEXT: ret i64 42 8 9 %first = getelementptr inbounds i8* %ptr, i32 0 10 %last = getelementptr inbounds i8* %ptr, i32 42 11 %first.int = ptrtoint i8* %first to i64 12 %last.int = ptrtoint i8* %last to i64 13 %diff = sub i64 %last.int, %first.int 14 ret i64 %diff 15 } 16 17 define i64 @ptrdiff2(i8* %ptr) { 18 ; CHECK: @ptrdiff2 19 ; CHECK-NEXT: ret i64 42 20 21 %first1 = getelementptr inbounds i8* %ptr, i32 0 22 %first2 = getelementptr inbounds i8* %first1, i32 1 23 %first3 = getelementptr inbounds i8* %first2, i32 2 24 %first4 = getelementptr inbounds i8* %first3, i32 4 25 %last1 = getelementptr inbounds i8* %first2, i32 48 26 %last2 = getelementptr inbounds i8* %last1, i32 8 27 %last3 = getelementptr inbounds i8* %last2, i32 -4 28 %last4 = getelementptr inbounds i8* %last3, i32 -4 29 %first.int = ptrtoint i8* %first4 to i64 30 %last.int = ptrtoint i8* %last4 to i64 31 %diff = sub i64 %last.int, %first.int 32 ret i64 %diff 33 } 34 35 define i64 @ptrdiff3(i8* %ptr) { 36 ; Don't bother with non-inbounds GEPs. 37 ; CHECK: @ptrdiff3 38 ; CHECK: getelementptr 39 ; CHECK: sub 40 ; CHECK: ret 41 42 %first = getelementptr i8* %ptr, i32 0 43 %last = getelementptr i8* %ptr, i32 42 44 %first.int = ptrtoint i8* %first to i64 45 %last.int = ptrtoint i8* %last to i64 46 %diff = sub i64 %last.int, %first.int 47 ret i64 %diff 48 } 49