path: root/test/Transforms/InstCombine/phi-select-constant.ll

; RUN: opt < %s -S -instcombine | FileCheck %s
@A = extern_weak global i32, align 4
@B = extern_weak global i32, align 4

define i32 @foo(i1 %which) {
entry:
  br i1 %which, label %final, label %delay

delay:
  br label %final

; CHECK-LABEL: @foo
; CHECK-LABEL: final:
; CHECK: phi i32 [ 1, %entry ], [ select (i1 icmp eq (i32* @A, i32* @B), i32 2, i32 1), %delay ]
final:
  %use2 = phi i1 [ false, %entry ], [ icmp eq (i32* @A, i32* @B), %delay ]
  %value = select i1 %use2, i32 2, i32 1
  ret i32 %value
}


; test folding of select into phi for vectors.
define <4 x i64> @vec1(i1 %which) {
entry:
  br i1 %which, label %final, label %delay

delay:
 br label %final

final:
; CHECK-LABEL: @vec1
; CHECK-LABEL: final:
; CHECK: %phinode = phi <4 x i64> [ zeroinitializer, %entry ], [ <i64 0, i64 0, i64 126, i64 127>, %delay ]
; CHECK-NOT: select
; CHECK: ret <4 x i64> %phinode
 %phinode =  phi <4 x i1> [ <i1 true, i1 true, i1 true, i1 true>, %entry ], [ <i1 true, i1 true, i1 false, i1 false>, %delay ]
 %sel = select <4 x i1> %phinode, <4 x i64> zeroinitializer, <4 x i64> <i64 124, i64 125, i64 126, i64 127>
 ret <4 x i64> %sel
}

define <4 x i64> @vec2(i1 %which) {
entry:
  br i1 %which, label %final, label %delay

delay:
 br label %final

final:
; CHECK-LABEL: @vec2
; CHECK-LABEL: final:
; CHECK: %phinode = phi <4 x i64> [ <i64 124, i64 125, i64 126, i64 127>, %entry ], [ <i64 0, i64 125, i64 0, i64 127>, %delay ]
; CHECK-NOT: select
; CHECK: ret <4 x i64> %phinode
 %phinode =  phi <4 x i1> [ <i1 false, i1 false, i1 false, i1 false>, %entry ], [ <i1 true, i1 false, i1 true, i1 false>, %delay ]
 %sel = select <4 x i1> %phinode, <4 x i64> zeroinitializer, <4 x i64> <i64 124, i64 125, i64 126, i64 127>
 ret <4 x i64> %sel
}