llvm/test/Transforms/InstCombine/select_with_identical_phi.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -S -passes=instcombine | FileCheck %s
@A = extern_weak global float, align 4

; %same.as.v1 is a select with two phis %v1 and %phi.to.remove as the true
; and false values, while %v1 and %phi.to.remove are actually the same.
; Fold the selection instruction %same.as.v1 to %v1.
define void @select_with_identical_phi(ptr %m, ptr %n, i32 %count) {
; CHECK-LABEL: @select_with_identical_phi(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
; CHECK:       for.body:
; CHECK-NEXT:    [[V0:%.*]] = phi float [ 0x4415AF1D80000000, [[ENTRY:%.*]] ], [ [[V0_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[V1:%.*]] = phi float [ 0xC415AF1D80000000, [[ENTRY]] ], [ [[V1_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC_I:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[Q:%.*]] = phi ptr [ [[M:%.*]], [[ENTRY]] ], [ [[Q_NEXT:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[C:%.*]] = phi ptr [ [[N:%.*]], [[ENTRY]] ], [ [[C_NEXT:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[Q_LOAD:%.*]] = load float, ptr [[Q]], align 4
; CHECK-NEXT:    [[C_LOAD:%.*]] = load float, ptr [[C]], align 4
; CHECK-NEXT:    [[SUB:%.*]] = fsub float [[Q_LOAD]], [[C_LOAD]]
; CHECK-NEXT:    [[CMP1:%.*]] = fcmp olt float [[SUB]], [[V0]]
; CHECK-NEXT:    [[V0_1]] = select i1 [[CMP1]], float [[SUB]], float [[V0]]
; CHECK-NEXT:    [[CMP2:%.*]] = fcmp ogt float [[SUB]], [[V1]]
; CHECK-NEXT:    [[V1_1]] = select i1 [[CMP2]], float [[SUB]], float [[V1]]
; CHECK-NEXT:    [[INC_I]] = add nuw nsw i32 [[I]], 1
; CHECK-NEXT:    [[Q_NEXT]] = getelementptr inbounds nuw i8, ptr [[Q]], i64 4
; CHECK-NEXT:    [[C_NEXT]] = getelementptr inbounds nuw i8, ptr [[C]], i64 4
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp eq i32 [[INC_I]], [[COUNT:%.*]]
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[EXIT:%.*]], label [[FOR_BODY]]
; CHECK:       exit:
; CHECK-NEXT:    store float [[V1_1]], ptr @A, align 4
; CHECK-NEXT:    ret void
;
entry:
  br label %for.body

for.body:                                    ; preds = %entry, %for.body
  %v0 = phi float [ 0x4415AF1D80000000, %entry ], [ %v0.1, %for.body ]
  %v1 = phi float [ 0xC415AF1D80000000, %entry ], [ %v1.1, %for.body ]
  %phi.to.remove = phi float [ 0xC415AF1D80000000, %entry ], [ %phi.to.remove.next, %for.body ]
  %i = phi i32 [ 0, %entry ], [ %inc.i, %for.body ]
  %q = phi ptr [ %m, %entry ], [ %q.next, %for.body ]
  %c = phi ptr [ %n, %entry ], [ %c.next, %for.body ]
  %q.load = load float, ptr %q
  %c.load = load float, ptr %c
  %sub = fsub float %q.load, %c.load
  %cmp1 = fcmp olt float %sub, %v0
  %v0.1 = select i1 %cmp1, float %sub, float %v0
  %same.as.v1 = select i1 %cmp1, float %v1, float %phi.to.remove
  %cmp2 = fcmp ogt float  %sub, %same.as.v1
  %v1.1 = select i1 %cmp2, float %sub, float %v1
  %phi.to.remove.next = select i1 %cmp2, float %sub, float %same.as.v1
  %inc.i = add nuw nsw i32 %i, 1
  %q.next = getelementptr inbounds i8, ptr %q, i64 4
  %c.next = getelementptr inbounds i8, ptr %c, i64 4
  %exitcond = icmp eq i32 %inc.i, %count
  br i1 %exitcond, label %exit, label %for.body

exit:
  %vl.1.lcssa = phi float [ %v1.1, %for.body ]
  store float %vl.1.lcssa, ptr @A
  ret void
}

; Reduced from select_with_identical_phi().
; Check that %same.as.v1 can be folded.
define void @select_with_identical_phi_2(i1 %cmp1, i1 %cmp2, float %x) {
; CHECK-LABEL: @select_with_identical_phi_2(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
; CHECK:       for.body:
; CHECK-NEXT:    [[V1:%.*]] = phi float [ 0xC415AF1D80000000, [[ENTRY:%.*]] ], [ [[V1_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC_I:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[V1_1]] = select i1 [[CMP2:%.*]], float [[X:%.*]], float [[V1]]
; CHECK-NEXT:    [[INC_I]] = add nuw nsw i32 [[I]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp eq i32 [[INC_I]], 100
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[EXIT:%.*]], label [[FOR_BODY]]
; CHECK:       exit:
; CHECK-NEXT:    store float [[V1_1]], ptr @A, align 4
; CHECK-NEXT:    ret void
;
entry:
  br label %for.body

for.body:                                    ; preds = %entry, %for.body
  %v1 = phi float [ 0xC415AF1D80000000, %entry ], [ %v1.1, %for.body ]
  %phi.to.remove = phi float [ 0xC415AF1D80000000, %entry ], [ %phi.to.remove.next, %for.body ]
  %i = phi i32 [ 0, %entry ], [ %inc.i, %for.body ]
  %same.as.v1 = select i1 %cmp1, float %v1, float %phi.to.remove
  %v1.1 = select i1 %cmp2, float %x, float %v1
  %phi.to.remove.next = select i1 %cmp2, float %x, float %same.as.v1
  %inc.i = add nuw nsw i32 %i, 1
  %exitcond = icmp eq i32 %inc.i, 100
  br i1 %exitcond, label %exit, label %for.body

exit:
  %vl.1.lcssa = phi float [ %v1.1, %for.body ]
  store float %vl.1.lcssa, ptr @A
  ret void
}

; The difference from select_with_identical_phi_2() is that the true and false values in
; %phi.to.remove.next and %v1.1 are swapped.
; Check that %same.as.v1 can be folded.
define void @select_with_identical_phi_3(i1 %cmp1, i1 %cmp2, float %x) {
; CHECK-LABEL: @select_with_identical_phi_3(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
; CHECK:       for.body:
; CHECK-NEXT:    [[V1:%.*]] = phi float [ 0xC415AF1D80000000, [[ENTRY:%.*]] ], [ [[V1_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC_I:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[V1_1]] = select i1 [[CMP2:%.*]], float [[V1]], float [[X:%.*]]
; CHECK-NEXT:    [[INC_I]] = add nuw nsw i32 [[I]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp eq i32 [[INC_I]], 100
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[EXIT:%.*]], label [[FOR_BODY]]
; CHECK:       exit:
; CHECK-NEXT:    store float [[V1_1]], ptr @A, align 4
; CHECK-NEXT:    ret void
;
entry:
  br label %for.body

for.body:                                    ; preds = %entry, %for.body
  %v1 = phi float [ 0xC415AF1D80000000, %entry ], [ %v1.1, %for.body ]
  %phi.to.remove = phi float [ 0xC415AF1D80000000, %entry ], [ %phi.to.remove.next, %for.body ]
  %i = phi i32 [ 0, %entry ], [ %inc.i, %for.body ]
  %same.as.v1 = select i1 %cmp1, float %v1, float %phi.to.remove
  %v1.1 = select i1 %cmp2, float %v1, float %x
  %phi.to.remove.next = select i1 %cmp2, float %same.as.v1, float %x
  %inc.i = add nuw nsw i32 %i, 1
  %exitcond = icmp eq i32 %inc.i, 100
  br i1 %exitcond, label %exit, label %for.body

exit:
  %vl.1.lcssa = phi float [ %v1.1, %for.body ]
  store float %vl.1.lcssa, ptr @A
  ret void
}

; The difference from select_with_identical_phi_2() is that the true and false values in
; same.as.v1 are swapped.
; Check that %same.as.v1 can be folded.
define void @select_with_identical_phi_4(i1 %cmp1, i1 %cmp2, float %x) {
; CHECK-LABEL: @select_with_identical_phi_4(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
; CHECK:       for.body:
; CHECK-NEXT:    [[V1:%.*]] = phi float [ 0xC415AF1D80000000, [[ENTRY:%.*]] ], [ [[V1_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC_I:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[V1_1]] = select i1 [[CMP2:%.*]], float [[X:%.*]], float [[V1]]
; CHECK-NEXT:    [[INC_I]] = add nuw nsw i32 [[I]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp eq i32 [[INC_I]], 100
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[EXIT:%.*]], label [[FOR_BODY]]
; CHECK:       exit:
; CHECK-NEXT:    store float [[V1_1]], ptr @A, align 4
; CHECK-NEXT:    ret void
;
entry:
  br label %for.body

for.body:                                    ; preds = %entry, %for.body
  %v1 = phi float [ 0xC415AF1D80000000, %entry ], [ %v1.1, %for.body ]
  %phi.to.remove = phi float [ 0xC415AF1D80000000, %entry ], [ %phi.to.remove.next, %for.body ]
  %i = phi i32 [ 0, %entry ], [ %inc.i, %for.body ]
  %same.as.v1 = select i1 %cmp1, float %phi.to.remove, float %v1
  %v1.1 = select i1 %cmp2, float %x, float %v1
  %phi.to.remove.next = select i1 %cmp2, float %x, float %same.as.v1
  %inc.i = add nuw nsw i32 %i, 1
  %exitcond = icmp eq i32 %inc.i, 100
  br i1 %exitcond, label %exit, label %for.body

exit:
  %vl.1.lcssa = phi float [ %v1.1, %for.body ]
  store float %vl.1.lcssa, ptr @A
  ret void
}

; The difference from select_with_identical_phi() is that the true and false values in
; %same.as.v1, %phi.to.remove.next and %v1.1 are swapped.
; Check that %same.as.v1 can be folded.
define void @select_with_identical_phi_5(i1 %cmp1, i1 %cmp2, float %x) {
; CHECK-LABEL: @select_with_identical_phi_5(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
; CHECK:       for.body:
; CHECK-NEXT:    [[V1:%.*]] = phi float [ 0xC415AF1D80000000, [[ENTRY:%.*]] ], [ [[V1_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC_I:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[V1_1]] = select i1 [[CMP2:%.*]], float [[V1]], float [[X:%.*]]
; CHECK-NEXT:    [[INC_I]] = add nuw nsw i32 [[I]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp eq i32 [[INC_I]], 100
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[EXIT:%.*]], label [[FOR_BODY]]
; CHECK:       exit:
; CHECK-NEXT:    store float [[V1_1]], ptr @A, align 4
; CHECK-NEXT:    ret void
;
entry:
  br label %for.body

for.body:                                    ; preds = %entry, %for.body
  %v1 = phi float [ 0xC415AF1D80000000, %entry ], [ %v1.1, %for.body ]
  %phi.to.remove = phi float [ 0xC415AF1D80000000, %entry ], [ %phi.to.remove.next, %for.body ]
  %i = phi i32 [ 0, %entry ], [ %inc.i, %for.body ]
  %same.as.v1 = select i1 %cmp1, float %phi.to.remove, float %v1
  %v1.1 = select i1 %cmp2, float %v1, float %x
  %phi.to.remove.next = select i1 %cmp2, float %same.as.v1, float %x
  %inc.i = add nuw nsw i32 %i, 1
  %exitcond = icmp eq i32 %inc.i, 100
  br i1 %exitcond, label %exit, label %for.body

exit:
  %vl.1.lcssa = phi float [ %v1.1, %for.body ]
  store float %vl.1.lcssa, ptr @A
  ret void
}

; The difference from select_with_identical_phi_2() is that not all phis are sorted with
; the same order of incoming BBs.
; Check that %same.as.v1 can be folded.
define void @select_with_identical_phi_6(i1 %cmp1, i1 %cmp2, float %x) {
; CHECK-LABEL: @select_with_identical_phi_6(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
; CHECK:       for.body:
; CHECK-NEXT:    [[V1:%.*]] = phi float [ 0xC415AF1D80000000, [[ENTRY:%.*]] ], [ [[V1_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC_I:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[V1_1]] = select i1 [[CMP2:%.*]], float [[X:%.*]], float [[V1]]
; CHECK-NEXT:    [[INC_I]] = add nuw nsw i32 [[I]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp eq i32 [[INC_I]], 100
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[EXIT:%.*]], label [[FOR_BODY]]
; CHECK:       exit:
; CHECK-NEXT:    store float [[V1_1]], ptr @A, align 4
; CHECK-NEXT:    ret void
;
entry:
  br label %for.body

for.body:                                    ; preds = %entry, %for.body
  %v1 = phi float [ 0xC415AF1D80000000, %entry ], [ %v1.1, %for.body ]
  %phi.to.remove = phi float [ %phi.to.remove.next, %for.body ], [ 0xC415AF1D80000000, %entry ]
  %i = phi i32 [ 0, %entry ], [ %inc.i, %for.body ]
  %same.as.v1 = select i1 %cmp1, float %v1, float %phi.to.remove
  %v1.1 = select i1 %cmp2, float %x, float %v1
  %phi.to.remove.next = select i1 %cmp2, float %x, float %same.as.v1
  %inc.i = add nuw nsw i32 %i, 1
  %exitcond = icmp eq i32 %inc.i, 100
  br i1 %exitcond, label %exit, label %for.body

exit:
  %vl.1.lcssa = phi float [ %v1.1, %for.body ]
  store float %vl.1.lcssa, ptr @A
  ret void
}

; %v1 and %phi.to.remove do not have the same start value.
; Cannot fold %same.as.v1.
define void @select_with_identical_phi_negative_1(i1 %cmp1, i1 %cmp2, float %x) {
; CHECK-LABEL: @select_with_identical_phi_negative_1(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
; CHECK:       for.body:
; CHECK-NEXT:    [[V1:%.*]] = phi float [ 0x4415AF1D80000000, [[ENTRY:%.*]] ], [ [[V1_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[PHI_TO_REMOVE:%.*]] = phi float [ 0xC415AF1D80000000, [[ENTRY]] ], [ [[PHI_TO_REMOVE_NEXT:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC_I:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[SAME_AS_V1:%.*]] = select i1 [[CMP1:%.*]], float [[V1]], float [[PHI_TO_REMOVE]]
; CHECK-NEXT:    [[V1_1]] = select i1 [[CMP2:%.*]], float [[X:%.*]], float [[V1]]
; CHECK-NEXT:    [[PHI_TO_REMOVE_NEXT]] = select i1 [[CMP2]], float [[X]], float [[SAME_AS_V1]]
; CHECK-NEXT:    [[INC_I]] = add nuw nsw i32 [[I]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp eq i32 [[INC_I]], 100
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[EXIT:%.*]], label [[FOR_BODY]]
; CHECK:       exit:
; CHECK-NEXT:    store float [[V1_1]], ptr @A, align 4
; CHECK-NEXT:    ret void
;
entry:
  br label %for.body

for.body:                                    ; preds = %entry, %for.body
  %v1 = phi float [ 0x4415AF1D80000000, %entry ], [ %v1.1, %for.body ]
  %phi.to.remove = phi float [ 0xC415AF1D80000000, %entry ], [ %phi.to.remove.next, %for.body ]
  %i = phi i32 [ 0, %entry ], [ %inc.i, %for.body ]
  %same.as.v1 = select i1 %cmp1, float %v1, float %phi.to.remove
  %v1.1 = select i1 %cmp2, float %x, float %v1
  %phi.to.remove.next = select i1 %cmp2, float %x, float %same.as.v1
  %inc.i = add nuw nsw i32 %i, 1
  %exitcond = icmp eq i32 %inc.i, 100
  br i1 %exitcond, label %exit, label %for.body

exit:
  %vl.1.lcssa = phi float [ %v1.1, %for.body ]
  store float %vl.1.lcssa, ptr @A
  ret void
}

; %v1 and %phi.to.remove do not act as the same phi since %v1.1 and %phi.to.remove.next do not evolve the same.
; Cannot fold %same.as.v1.
define void @select_with_identical_phi_negative_2(i1 %cmp1, i1 %cmp2, float %x) {
; CHECK-LABEL: @select_with_identical_phi_negative_2(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
; CHECK:       for.body:
; CHECK-NEXT:    [[V1:%.*]] = phi float [ 0xC415AF1D80000000, [[ENTRY:%.*]] ], [ [[V1_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[PHI_TO_REMOVE:%.*]] = phi float [ 0xC415AF1D80000000, [[ENTRY]] ], [ [[PHI_TO_REMOVE_NEXT:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC_I:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[SAME_AS_V1:%.*]] = select i1 [[CMP1:%.*]], float [[V1]], float [[PHI_TO_REMOVE]]
; CHECK-NEXT:    [[V1_1]] = select i1 [[CMP2:%.*]], float [[V1]], float [[X:%.*]]
; CHECK-NEXT:    [[PHI_TO_REMOVE_NEXT]] = select i1 [[CMP2]], float [[X]], float [[SAME_AS_V1]]
; CHECK-NEXT:    [[INC_I]] = add nuw nsw i32 [[I]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp eq i32 [[INC_I]], 100
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[EXIT:%.*]], label [[FOR_BODY]]
; CHECK:       exit:
; CHECK-NEXT:    store float [[V1_1]], ptr @A, align 4
; CHECK-NEXT:    ret void
;
entry:
  br label %for.body

for.body:                                    ; preds = %entry, %for.body
  %v1 = phi float [ 0xC415AF1D80000000, %entry ], [ %v1.1, %for.body ]
  %phi.to.remove = phi float [ 0xC415AF1D80000000, %entry ], [ %phi.to.remove.next, %for.body ]
  %i = phi i32 [ 0, %entry ], [ %inc.i, %for.body ]
  %same.as.v1 = select i1 %cmp1, float %v1, float %phi.to.remove
  %v1.1 = select i1 %cmp2, float %v1, float %x
  %phi.to.remove.next = select i1 %cmp2, float %x, float %same.as.v1
  %inc.i = add nuw nsw i32 %i, 1
  %exitcond = icmp eq i32 %inc.i, 100
  br i1 %exitcond, label %exit, label %for.body

exit:
  %vl.1.lcssa = phi float [ %v1.1, %for.body ]
  store float %vl.1.lcssa, ptr @A
  ret void
}

; %v1 and %phi.to.remove do not act as the same phi since %v1.1 and %phi.to.remove.next do not
; have the same condition.
; Cannot fold %same.as.v1.
define void @select_with_identical_phi_negative_3(i1 %cmp1, i1 %cmp2, i1 %cmp3, float %x) {
; CHECK-LABEL: @select_with_identical_phi_negative_3(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
; CHECK:       for.body:
; CHECK-NEXT:    [[V1:%.*]] = phi float [ 0xC415AF1D80000000, [[ENTRY:%.*]] ], [ [[V1_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[PHI_TO_REMOVE:%.*]] = phi float [ 0xC415AF1D80000000, [[ENTRY]] ], [ [[PHI_TO_REMOVE_NEXT:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC_I:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[SAME_AS_V1:%.*]] = select i1 [[CMP1:%.*]], float [[V1]], float [[PHI_TO_REMOVE]]
; CHECK-NEXT:    [[V1_1]] = select i1 [[CMP3:%.*]], float [[V1]], float [[X:%.*]]
; CHECK-NEXT:    [[PHI_TO_REMOVE_NEXT]] = select i1 [[CMP2:%.*]], float [[X]], float [[SAME_AS_V1]]
; CHECK-NEXT:    [[INC_I]] = add nuw nsw i32 [[I]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp eq i32 [[INC_I]], 100
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[EXIT:%.*]], label [[FOR_BODY]]
; CHECK:       exit:
; CHECK-NEXT:    store float [[V1_1]], ptr @A, align 4
; CHECK-NEXT:    ret void
;
entry:
  br label %for.body

for.body:                                    ; preds = %entry, %for.body
  %v1 = phi float [ 0xC415AF1D80000000, %entry ], [ %v1.1, %for.body ]
  %phi.to.remove = phi float [ 0xC415AF1D80000000, %entry ], [ %phi.to.remove.next, %for.body ]
  %i = phi i32 [ 0, %entry ], [ %inc.i, %for.body ]
  %same.as.v1 = select i1 %cmp1, float %v1, float %phi.to.remove
  %v1.1 = select i1 %cmp3, float %v1, float %x
  %phi.to.remove.next = select i1 %cmp2, float %x, float %same.as.v1
  %inc.i = add nuw nsw i32 %i, 1
  %exitcond = icmp eq i32 %inc.i, 100
  br i1 %exitcond, label %exit, label %for.body

exit:
  %vl.1.lcssa = phi float [ %v1.1, %for.body ]
  store float %vl.1.lcssa, ptr @A
  ret void
}

; The true and false values of %same.as.v1 are not really the same phi.
; Cannot fold %same.as.v1.
define void @select_with_identical_phi_negative_4(i1 %cmp1, i1 %cmp2, float %x) {
; CHECK-LABEL: @select_with_identical_phi_negative_4(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
; CHECK:       for.body:
; CHECK-NEXT:    [[V0:%.*]] = phi float [ 0x4415AF1D80000000, [[ENTRY:%.*]] ], [ [[V0_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[V1:%.*]] = phi float [ 0xC415AF1D80000000, [[ENTRY]] ], [ [[V1_1:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[PHI_TO_REMOVE:%.*]] = phi float [ 0xC415AF1D80000000, [[ENTRY]] ], [ [[PHI_TO_REMOVE_NEXT:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC_I:%.*]], [[FOR_BODY]] ]
; CHECK-NEXT:    [[SAME_AS_V1:%.*]] = select i1 [[CMP1:%.*]], float [[V0]], float [[PHI_TO_REMOVE]]
; CHECK-NEXT:    [[V1_1]] = select i1 [[CMP2:%.*]], float [[X:%.*]], float [[V1]]
; CHECK-NEXT:    [[PHI_TO_REMOVE_NEXT]] = select i1 [[CMP2]], float [[X]], float [[SAME_AS_V1]]
; CHECK-NEXT:    [[V0_1]] = fadd float [[V0]], 1.000000e+00
; CHECK-NEXT:    [[INC_I]] = add nuw nsw i32 [[I]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp eq i32 [[INC_I]], 100
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[EXIT:%.*]], label [[FOR_BODY]]
; CHECK:       exit:
; CHECK-NEXT:    store float [[V1_1]], ptr @A, align 4
; CHECK-NEXT:    ret void
;
entry:
  br label %for.body

for.body:                                    ; preds = %entry, %for.body
  %v0 = phi float [ 0x4415AF1D80000000, %entry ], [ %v0.1, %for.body ]
  %v1 = phi float [ 0xC415AF1D80000000, %entry ], [ %v1.1, %for.body ]
  %phi.to.remove = phi float [ 0xC415AF1D80000000, %entry ], [ %phi.to.remove.next, %for.body ]
  %i = phi i32 [ 0, %entry ], [ %inc.i, %for.body ]
  %same.as.v1 = select i1 %cmp1, float %v0, float %phi.to.remove
  %v1.1 = select i1 %cmp2, float %x, float %v1
  %phi.to.remove.next = select i1 %cmp2, float %x, float %same.as.v1
  %v0.1 = fadd float %v0, 1.0
  %inc.i = add nuw nsw i32 %i, 1
  %exitcond = icmp eq i32 %inc.i, 100
  br i1 %exitcond, label %exit, label %for.body

exit:
  %vl.1.lcssa = phi float [ %v1.1, %for.body ]
  store float %vl.1.lcssa, ptr @A
  ret void
}