non-local-offset.ll   [plain text]

; RUN: opt -basicaa -gvn -S < %s | FileCheck %s

target datalayout = "e-p:64:64:64"

; GVN should ignore the store to p[1] to see that the load from p[0] is
; fully redundant.

; CHECK: @yes
; CHECK: if.then:
; CHECK-NEXT: store i32 0, i32* %q
; CHECK-NEXT: ret void

define void @yes(i1 %c, i32* %p, i32* %q) nounwind {
entry:
  store i32 0, i32* %p
  %p1 = getelementptr inbounds i32* %p, i64 1
  store i32 1, i32* %p1
  br i1 %c, label %if.else, label %if.then

if.then:
  %t = load i32* %p
  store i32 %t, i32* %q
  ret void

if.else:
  ret void
}

; GVN should ignore the store to p[1] to see that the first load from p[0] is
; fully redundant. However, the second load is larger, so it's not a simple
; redundancy.

; CHECK: @watch_out_for_size_change
; CHECK: if.then:
; CHECK-NEXT: store i32 0, i32* %q
; CHECK-NEXT: ret void
; CHECK: if.else:
; CHECK: load i64* %pc
; CHECK: store i64

define void @watch_out_for_size_change(i1 %c, i32* %p, i32* %q) nounwind {
entry:
  store i32 0, i32* %p
  %p1 = getelementptr inbounds i32* %p, i64 1
  store i32 1, i32* %p1
  br i1 %c, label %if.else, label %if.then

if.then:
  %t = load i32* %p
  store i32 %t, i32* %q
  ret void

if.else:
  %pc = bitcast i32* %p to i64*
  %qc = bitcast i32* %q to i64*
  %t64 = load i64* %pc
  store i64 %t64, i64* %qc
  ret void
}