xref: /llvm-project/llvm/test/Analysis/ValueTracking/knownbits-sat-addsub.ll (revision 877cb9a2edc9057d70321e436e5ea8ccc1a87140)

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

declare i8 @llvm.sadd.sat.i8(i8, i8)
declare i8 @llvm.ssub.sat.i8(i8, i8)
declare i8 @llvm.uadd.sat.i8(i8, i8)
declare i8 @llvm.usub.sat.i8(i8, i8)

define i1 @uadd_sat_overflow(i8 %x, i8 %y) {
; CHECK-LABEL: @uadd_sat_overflow(
; CHECK-NEXT:    ret i1 false
;
  %lhs = or i8 %x, 128
  %rhs = or i8 %y, 128
  %exp = call i8 @llvm.uadd.sat.i8(i8 %lhs, i8 %rhs)
  %r = icmp eq i8 %exp, 254
  ret i1 %r
}

define i1 @uadd_sat_overflow_fail(i8 %x, i8 %y) {
; CHECK-LABEL: @uadd_sat_overflow_fail(
; CHECK-NEXT:    [[LHS:%.*]] = or i8 [[X:%.*]], -128
; CHECK-NEXT:    [[RHS:%.*]] = or i8 [[Y:%.*]], 126
; CHECK-NEXT:    [[EXP:%.*]] = call i8 @llvm.uadd.sat.i8(i8 [[LHS]], i8 [[RHS]])
; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[EXP]], -2
; CHECK-NEXT:    ret i1 [[R]]
;
  %lhs = or i8 %x, 128
  %rhs = or i8 %y, 126
  %exp = call i8 @llvm.uadd.sat.i8(i8 %lhs, i8 %rhs)
  %r = icmp eq i8 %exp, 254
  ret i1 %r
}

define i1 @usub_sat_overflow(i8 %x, i8 %y) {
; CHECK-LABEL: @usub_sat_overflow(
; CHECK-NEXT:    ret i1 false
;
  %lhs = and i8 %x, 127
  %rhs = or i8 %y, 128
  %exp = call i8 @llvm.usub.sat.i8(i8 %lhs, i8 %rhs)
  %r = icmp eq i8 %exp, 1
  ret i1 %r
}

define i1 @usub_sat_overflow_fail(i8 %x, i8 %y) {
; CHECK-LABEL: @usub_sat_overflow_fail(
; CHECK-NEXT:    [[LHS:%.*]] = and i8 [[X:%.*]], 127
; CHECK-NEXT:    [[RHS:%.*]] = or i8 [[Y:%.*]], 126
; CHECK-NEXT:    [[EXP:%.*]] = call i8 @llvm.usub.sat.i8(i8 [[LHS]], i8 [[RHS]])
; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[EXP]], 1
; CHECK-NEXT:    ret i1 [[R]]
;
  %lhs = and i8 %x, 127
  %rhs = or i8 %y, 126
  %exp = call i8 @llvm.usub.sat.i8(i8 %lhs, i8 %rhs)
  %r = icmp eq i8 %exp, 1
  ret i1 %r
}

define i1 @sadd_sat_overflow_pos(i8 %x, i8 %y) {
; CHECK-LABEL: @sadd_sat_overflow_pos(
; CHECK-NEXT:    ret i1 false
;
  %xx = and i8 %x, 127
  %yy = and i8 %y, 127
  %lhs = or i8 %xx, 64
  %rhs = or i8 %yy, 65
  %exp = call i8 @llvm.sadd.sat.i8(i8 %lhs, i8 %rhs)
  %r = icmp eq i8 %exp, 128
  ret i1 %r
}

define i1 @sadd_sat_low_bits(i8 %x, i8 %y) {
; CHECK-LABEL: @sadd_sat_low_bits(
; CHECK-NEXT:    ret i1 false
;
  %xx = and i8 %x, 15
  %yy = and i8 %y, 15
  %lhs = or i8 %xx, 1
  %rhs = and i8 %yy, -2
  %exp = call i8 @llvm.sadd.sat.i8(i8 %lhs, i8 %rhs)
  %and = and i8 %exp, 1
  %r = icmp eq i8 %and, 0
  ret i1 %r
}

define i1 @sadd_sat_fail_may_overflow(i8 %x, i8 %y) {
; CHECK-LABEL: @sadd_sat_fail_may_overflow(
; CHECK-NEXT:    [[LHS:%.*]] = or i8 [[X:%.*]], 1
; CHECK-NEXT:    [[RHS:%.*]] = and i8 [[Y:%.*]], -2
; CHECK-NEXT:    [[EXP:%.*]] = call i8 @llvm.sadd.sat.i8(i8 [[LHS]], i8 [[RHS]])
; CHECK-NEXT:    [[AND:%.*]] = and i8 [[EXP]], 1
; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[AND]], 0
; CHECK-NEXT:    ret i1 [[R]]
;
  %lhs = or i8 %x, 1
  %rhs = and i8 %y, -2
  %exp = call i8 @llvm.sadd.sat.i8(i8 %lhs, i8 %rhs)
  %and = and i8 %exp, 1
  %r = icmp eq i8 %and, 0
  ret i1 %r
}

define i1 @sadd_sat_overflow_neg(i8 %x, i8 %y) {
; CHECK-LABEL: @sadd_sat_overflow_neg(
; CHECK-NEXT:    ret i1 false
;
  %lhs = or i8 %x, 192
  %rhs = or i8 %y, 191
  %exp = call i8 @llvm.sadd.sat.i8(i8 %lhs, i8 %rhs)
  %r = icmp eq i8 %exp, 127
  ret i1 %r
}

define i1 @ssub_sat_overflow_neg(i8 %x, i8 %y) {
; CHECK-LABEL: @ssub_sat_overflow_neg(
; CHECK-NEXT:    ret i1 false
;
  %xx = and i8 %x, 112
  %yy = and i8 %y, 127
  %lhs = or i8 %xx, 128
  %rhs = or i8 %yy, 126
  %exp = call i8 @llvm.ssub.sat.i8(i8 %lhs, i8 %rhs)
  %r = icmp eq i8 %exp, 32
  ret i1 %r
}

define i1 @ssub_sat_low_bits(i8 %x, i8 %y) {
; CHECK-LABEL: @ssub_sat_low_bits(
; CHECK-NEXT:    ret i1 false
;
  %xx = and i8 %x, 15
  %yy = and i8 %y, 15
  %lhs = or i8 %xx, 17
  %rhs = and i8 %yy, -2
  %exp = call i8 @llvm.ssub.sat.i8(i8 %lhs, i8 %rhs)
  %and = and i8 %exp, 1
  %r = icmp eq i8 %and, 0
  ret i1 %r
}

define i1 @ssub_sat_fail_may_overflow(i8 %x, i8 %y) {
; CHECK-LABEL: @ssub_sat_fail_may_overflow(
; CHECK-NEXT:    ret i1 false
;
  %xx = and i8 %x, 15
  %yy = and i8 %y, 15
  %lhs = or i8 %xx, 1
  %rhs = and i8 %yy, -2
  %exp = call i8 @llvm.ssub.sat.i8(i8 %lhs, i8 %rhs)
  %and = and i8 %exp, 1
  %r = icmp eq i8 %and, 0
  ret i1 %r
}

define i1 @ssub_sat_overflow_pos(i8 %x, i8 %y) {
; CHECK-LABEL: @ssub_sat_overflow_pos(
; CHECK-NEXT:    ret i1 false
;
  %xx = and i8 %x, 24
  %yy = and i8 %y, 3
  %lhs = or i8 %xx, 8
  %rhs = or i8 %yy, 128
  %exp = call i8 @llvm.ssub.sat.i8(i8 %lhs, i8 %rhs)
  %r = icmp eq i8 %exp, 128
  ret i1 %r
}