llvm/test/Transforms/InstCombine/extractvalue.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -passes=instcombine -S | FileCheck %s

declare void @bar({i32, i32} %a)
declare i32 @baz(i32 %a)

; Instcombine should fold various combinations of insertvalue and extractvalue
; together
define i32 @foo(i32 %a, i32 %b) {
; CHECK-LABEL: @foo(
; CHECK-NEXT:    [[TMP1:%.*]] = insertvalue { i32, i32 } undef, i32 [[A:%.*]], 0
; CHECK-NEXT:    [[S2:%.*]] = insertvalue { i32, i32 } [[TMP1]], i32 [[B:%.*]], 1
; CHECK-NEXT:    call void @bar({ i32, i32 } [[S2]])
; CHECK-NEXT:    [[TMP2:%.*]] = insertvalue { i32, i32 } undef, i32 [[A]], 0
; CHECK-NEXT:    [[S3:%.*]] = insertvalue { i32, i32 } [[TMP2]], i32 [[B]], 1
; CHECK-NEXT:    call void @bar({ i32, i32 } [[S3]])
; CHECK-NEXT:    ret i32 [[B]]
;
  %s1.1 = insertvalue {i32, i32} undef, i32 %a, 0
  %s1 = insertvalue {i32, i32} %s1.1, i32 %b, 1
  %v1 = extractvalue {i32, i32} %s1, 0
  %v2 = extractvalue {i32, i32} %s1, 1

  ; Build a nested struct and pull a sub struct out of it
  ; This requires instcombine to insert a few insertvalue instructions
  %ns1.1 = insertvalue {i32, {i32, i32}} undef, i32 %v1, 0
  %ns1.2 = insertvalue {i32, {i32, i32}} %ns1.1, i32 %v1, 1, 0
  %ns1   = insertvalue {i32, {i32, i32}} %ns1.2, i32 %v2, 1, 1
  %s2    = extractvalue {i32, {i32, i32}} %ns1, 1
  %v3    = extractvalue {i32, {i32, i32}} %ns1, 1, 1
  call void @bar({i32, i32} %s2)

  ; Use nested extractvalues to get to a value
  %s3    = extractvalue {i32, {i32, i32}} %ns1, 1
  %v4    = extractvalue {i32, i32} %s3, 1
  call void @bar({i32, i32} %s3)

  ; Use nested insertvalues to build a nested struct
  %s4.1 = insertvalue {i32, i32} undef, i32 %v3, 0
  %s4   = insertvalue {i32, i32} %s4.1, i32 %v4, 1
  %ns2  = insertvalue {i32, {i32, i32}} undef, {i32, i32} %s4, 1

  ; And now extract a single value from there
  %v5   = extractvalue {i32, {i32, i32}} %ns2, 1, 1

  ret i32 %v5
}

; The load + extractvalue should be converted
; to an inbounds gep + smaller load.
; The new load should be in the same spot as the old load.
define i32 @extract2gep(ptr %pair, ptr %P) {
; CHECK-LABEL: @extract2gep(
; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds nuw i8, ptr [[PAIR:%.*]], i64 4
; CHECK-NEXT:    [[E:%.*]] = load i32, ptr [[TMP1]], align 4
; CHECK-NEXT:    store i32 0, ptr [[P:%.*]], align 4
; CHECK-NEXT:    br label [[LOOP:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    [[C:%.*]] = call i32 @baz(i32 [[E]])
; CHECK-NEXT:    store i32 [[C]], ptr [[P]], align 4
; CHECK-NEXT:    [[COND:%.*]] = icmp eq i32 [[C]], 0
; CHECK-NEXT:    br i1 [[COND]], label [[END:%.*]], label [[LOOP]]
; CHECK:       end:
; CHECK-NEXT:    ret i32 [[E]]
;
  %L = load {i16, i32}, ptr %pair
  store i32 0, ptr %P
  br label %loop

loop:
  %E = extractvalue {i16, i32} %L, 1
  %C = call i32 @baz(i32 %E)
  store i32 %C, ptr %P
  %cond = icmp eq i32 %C, 0
  br i1 %cond, label %end, label %loop

end:
  ret i32 %E
}

; The load + extractvalues should be converted
; to a 3-index inbounds gep + smaller load.
define i16 @doubleextract2gep(ptr %arg) {
; CHECK-LABEL: @doubleextract2gep(
; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds nuw i8, ptr [[ARG:%.*]], i64 8
; CHECK-NEXT:    [[E2:%.*]] = load i16, ptr [[TMP1]], align 2
; CHECK-NEXT:    ret i16 [[E2]]
;
  %L = load {i16, {i32, i16}}, ptr %arg
  %E1 = extractvalue {i16, {i32, i16}} %L, 1
  %E2 = extractvalue {i32, i16} %E1, 1
  ret i16 %E2
}

; The load should be left unchanged since both parts are needed.
define i32 @nogep-multiuse(ptr %pair) {
; CHECK-LABEL: @nogep-multiuse(
; CHECK-NEXT:    [[L:%.*]] = load volatile { i32, i32 }, ptr [[PAIR:%.*]], align 4
; CHECK-NEXT:    [[LHS:%.*]] = extractvalue { i32, i32 } [[L]], 0
; CHECK-NEXT:    [[RHS:%.*]] = extractvalue { i32, i32 } [[L]], 1
; CHECK-NEXT:    [[R:%.*]] = add i32 [[LHS]], [[RHS]]
; CHECK-NEXT:    ret i32 [[R]]
;
  %L = load volatile {i32, i32}, ptr %pair
  %LHS = extractvalue {i32, i32} %L, 0
  %RHS = extractvalue {i32, i32} %L, 1
  %R = add i32 %LHS, %RHS
  ret i32 %R
}

; The load volatile should be left unchanged.
define i32 @nogep-volatile(ptr %pair) {
; CHECK-LABEL: @nogep-volatile(
; CHECK-NEXT:    [[L:%.*]] = load volatile { i32, i32 }, ptr [[PAIR:%.*]], align 4
; CHECK-NEXT:    [[E:%.*]] = extractvalue { i32, i32 } [[L]], 1
; CHECK-NEXT:    ret i32 [[E]]
;
  %L = load volatile {i32, i32}, ptr %pair
  %E = extractvalue {i32, i32} %L, 1
  ret i32 %E
}