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[InstCombine] Canonicalize icmp pred (X +/- C1), C2 into icmp pred X, C2 -/+ C1 with nowrap flag implied by with.overflow intrinsic #75511

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Dec 16, 2023
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[InstCombine] Canonicalize icmp pred (X +/- C1), C2 into icmp pred X, C2 -/+ C1 with nowrap flag implied by with.overflow intrinsic #75511

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4ac4033
[InstCombine] Add pre-commit tests from PR75360. NFC.
dtcxzyw Dec 15, 2023
7250691
[InstCombine] Canonicalize `icmp pred (X +/- C1), C2` into `icmp pred…
dtcxzyw Dec 15, 2023
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29 changes: 29 additions & 0 deletions llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3756,6 +3756,35 @@ Instruction *InstCombinerImpl::visitOr(BinaryOperator &I) {
}
}

/// Res, Overflow = xxx_with_overflow X, C1
/// Try to canonicalize the pattern "Overflow | icmp pred Res, C2" into
/// "Overflow | icmp pred X, C2 +/- C1".
const WithOverflowInst *WO;
const Value *WOV;
const APInt *C1, *C2;
if (match(&I, m_c_Or(m_CombineAnd(m_ExtractValue<1>(m_CombineAnd(
m_WithOverflowInst(WO), m_Value(WOV))),
m_Value(Ov)),
m_OneUse(m_ICmp(Pred, m_ExtractValue<0>(m_Deferred(WOV)),
m_APInt(C2))))) &&
(WO->getBinaryOp() == Instruction::Add ||
WO->getBinaryOp() == Instruction::Sub) &&
(ICmpInst::isEquality(Pred) ||
WO->isSigned() == ICmpInst::isSigned(Pred)) &&
match(WO->getRHS(), m_APInt(C1))) {
bool Overflow;
APInt NewC = WO->getBinaryOp() == Instruction::Add
? (ICmpInst::isSigned(Pred) ? C2->ssub_ov(*C1, Overflow)
: C2->usub_ov(*C1, Overflow))
: (ICmpInst::isSigned(Pred) ? C2->sadd_ov(*C1, Overflow)
: C2->uadd_ov(*C1, Overflow));
if (!Overflow || ICmpInst::isEquality(Pred)) {
Value *NewCmp = Builder.CreateICmp(
Pred, WO->getLHS(), ConstantInt::get(WO->getLHS()->getType(), NewC));
return BinaryOperator::CreateOr(Ov, NewCmp);
}
}

// (~x) | y --> ~(x & (~y)) iff that gets rid of inversions
if (sinkNotIntoOtherHandOfLogicalOp(I))
return &I;
Expand Down
275 changes: 275 additions & 0 deletions llvm/test/Transforms/InstCombine/canonicalize-or-with-overflow-icmp.ll
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@@ -0,0 +1,275 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
; RUN: opt < %s -passes=instcombine -S | FileCheck %s

declare { i32, i1 } @llvm.sadd.with.overflow.i32(i32, i32)
declare { i32, i1 } @llvm.ssub.with.overflow.i32(i32, i32)
declare { i32, i1 } @llvm.smul.with.overflow.i32(i32, i32)
declare { i32, i1 } @llvm.uadd.with.overflow.i32(i32, i32)

declare void @use(i1)

; Tests from PR75360
define i1 @ckd_add_unsigned(i31 %num) {
; CHECK-LABEL: define i1 @ckd_add_unsigned(
; CHECK-SAME: i31 [[NUM:%.*]]) {
; CHECK-NEXT: [[A2:%.*]] = icmp eq i31 [[NUM]], -1
; CHECK-NEXT: ret i1 [[A2]]
;
%a0 = zext i31 %num to i32
%a1 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %a0, i32 1)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp slt i32 %a3, 0
%a5 = or i1 %a2, %a4
ret i1 %a5
}

define i1 @ckd_add_unsigned_commuted(i31 %num) {
; CHECK-LABEL: define i1 @ckd_add_unsigned_commuted(
; CHECK-SAME: i31 [[NUM:%.*]]) {
; CHECK-NEXT: [[A2:%.*]] = icmp eq i31 [[NUM]], -1
; CHECK-NEXT: ret i1 [[A2]]
;
%a0 = zext i31 %num to i32
%a1 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %a0, i32 1)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp slt i32 %a3, 0
%a5 = or i1 %a4, %a2
ret i1 %a5
}

define i1 @ckd_add_unsigned_imply_true(i31 %num) {
; CHECK-LABEL: define i1 @ckd_add_unsigned_imply_true(
; CHECK-SAME: i31 [[NUM:%.*]]) {
; CHECK-NEXT: ret i1 true
;
%a0 = zext i31 %num to i32
%a1 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %a0, i32 1)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp sgt i32 %a3, -1
%a5 = or i1 %a2, %a4
ret i1 %a5
}

define i1 @canonicalize_or_sadd_with_overflow_icmp(i32 %a0) {
; CHECK-LABEL: define i1 @canonicalize_or_sadd_with_overflow_icmp(
; CHECK-SAME: i32 [[A0:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = add i32 [[A0]], -2147483647
; CHECK-NEXT: [[A5:%.*]] = icmp sgt i32 [[TMP1]], -1
; CHECK-NEXT: ret i1 [[A5]]
;
%a1 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %a0, i32 1)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp slt i32 %a3, 0
%a5 = or i1 %a2, %a4
ret i1 %a5
}

define i1 @canonicalize_or_ssub_with_overflow_icmp(i32 %a0) {
; CHECK-LABEL: define i1 @canonicalize_or_ssub_with_overflow_icmp(
; CHECK-SAME: i32 [[A0:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = icmp slt i32 [[A0]], 1
; CHECK-NEXT: ret i1 [[TMP1]]
;
%a1 = tail call { i32, i1 } @llvm.ssub.with.overflow.i32(i32 %a0, i32 1)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp slt i32 %a3, 0
%a5 = or i1 %a2, %a4
ret i1 %a5
}

define i1 @canonicalize_or_uadd_with_overflow_icmp(i32 %a0) {
; CHECK-LABEL: define i1 @canonicalize_or_uadd_with_overflow_icmp(
; CHECK-SAME: i32 [[A0:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = add i32 [[A0]], 1
; CHECK-NEXT: [[A5:%.*]] = icmp ult i32 [[TMP1]], 10
; CHECK-NEXT: ret i1 [[A5]]
;
%a1 = tail call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 %a0, i32 1)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp ult i32 %a3, 10
%a5 = or i1 %a2, %a4
ret i1 %a5
}

define i1 @canonicalize_or_sadd_with_overflow_icmp_eq(i32 %a0) {
; CHECK-LABEL: define i1 @canonicalize_or_sadd_with_overflow_icmp_eq(
; CHECK-SAME: i32 [[A0:%.*]]) {
; CHECK-NEXT: [[A2:%.*]] = icmp eq i32 [[A0]], 2147483647
; CHECK-NEXT: [[TMP1:%.*]] = icmp eq i32 [[A0]], 9
; CHECK-NEXT: [[A5:%.*]] = or i1 [[A2]], [[TMP1]]
; CHECK-NEXT: ret i1 [[A5]]
;
%a1 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %a0, i32 1)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp eq i32 %a3, 10
%a5 = or i1 %a2, %a4
ret i1 %a5
}

define i1 @canonicalize_or_uadd_with_overflow_icmp_ne(i32 %a0) {
; CHECK-LABEL: define i1 @canonicalize_or_uadd_with_overflow_icmp_ne(
; CHECK-SAME: i32 [[A0:%.*]]) {
; CHECK-NEXT: [[TMP1:%.*]] = icmp ne i32 [[A0]], 9
; CHECK-NEXT: ret i1 [[TMP1]]
;
%a1 = tail call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 %a0, i32 1)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp ne i32 %a3, 10
%a5 = or i1 %a2, %a4
ret i1 %a5
}

; Negative tests
define i1 @canonicalize_or_sadd_with_overflow_icmp_mismatched_pred(i32 %a0) {
; CHECK-LABEL: define i1 @canonicalize_or_sadd_with_overflow_icmp_mismatched_pred(
; CHECK-SAME: i32 [[A0:%.*]]) {
; CHECK-NEXT: [[A1:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[A0]], i32 1)
; CHECK-NEXT: [[A2:%.*]] = extractvalue { i32, i1 } [[A1]], 1
; CHECK-NEXT: [[A3:%.*]] = extractvalue { i32, i1 } [[A1]], 0
; CHECK-NEXT: [[A4:%.*]] = icmp ult i32 [[A3]], 2
; CHECK-NEXT: [[A5:%.*]] = or i1 [[A2]], [[A4]]
; CHECK-NEXT: ret i1 [[A5]]
;
%a1 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %a0, i32 1)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp ult i32 %a3, 2
%a5 = or i1 %a2, %a4
ret i1 %a5
}

define i1 @canonicalize_or_sadd_with_overflow_icmp_non_constant1(i32 %a0, i32 %c) {
; CHECK-LABEL: define i1 @canonicalize_or_sadd_with_overflow_icmp_non_constant1(
; CHECK-SAME: i32 [[A0:%.*]], i32 [[C:%.*]]) {
; CHECK-NEXT: [[A1:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[A0]], i32 [[C]])
; CHECK-NEXT: [[A2:%.*]] = extractvalue { i32, i1 } [[A1]], 1
; CHECK-NEXT: [[A3:%.*]] = extractvalue { i32, i1 } [[A1]], 0
; CHECK-NEXT: [[A4:%.*]] = icmp slt i32 [[A3]], 0
; CHECK-NEXT: [[A5:%.*]] = or i1 [[A2]], [[A4]]
; CHECK-NEXT: ret i1 [[A5]]
;
%a1 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %a0, i32 %c)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp slt i32 %a3, 0
%a5 = or i1 %a2, %a4
ret i1 %a5
}

define i1 @canonicalize_or_sadd_with_overflow_icmp_non_constant2(i32 %a0, i32 %c) {
; CHECK-LABEL: define i1 @canonicalize_or_sadd_with_overflow_icmp_non_constant2(
; CHECK-SAME: i32 [[A0:%.*]], i32 [[C:%.*]]) {
; CHECK-NEXT: [[A1:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[A0]], i32 1)
; CHECK-NEXT: [[A2:%.*]] = extractvalue { i32, i1 } [[A1]], 1
; CHECK-NEXT: [[A3:%.*]] = extractvalue { i32, i1 } [[A1]], 0
; CHECK-NEXT: [[A4:%.*]] = icmp slt i32 [[A3]], [[C]]
; CHECK-NEXT: [[A5:%.*]] = or i1 [[A2]], [[A4]]
; CHECK-NEXT: ret i1 [[A5]]
;
%a1 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %a0, i32 1)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp slt i32 %a3, %c
%a5 = or i1 %a2, %a4
ret i1 %a5
}

define i1 @canonicalize_or_sadd_with_overflow_icmp_multiuse(i32 %a0) {
; CHECK-LABEL: define i1 @canonicalize_or_sadd_with_overflow_icmp_multiuse(
; CHECK-SAME: i32 [[A0:%.*]]) {
; CHECK-NEXT: [[A1:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[A0]], i32 1)
; CHECK-NEXT: [[A2:%.*]] = extractvalue { i32, i1 } [[A1]], 1
; CHECK-NEXT: [[A3:%.*]] = extractvalue { i32, i1 } [[A1]], 0
; CHECK-NEXT: [[A4:%.*]] = icmp slt i32 [[A3]], 0
; CHECK-NEXT: call void @use(i1 [[A4]])
; CHECK-NEXT: [[A5:%.*]] = or i1 [[A2]], [[A4]]
; CHECK-NEXT: ret i1 [[A5]]
;
%a1 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %a0, i32 1)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp slt i32 %a3, 0
call void @use(i1 %a4)
%a5 = or i1 %a2, %a4
ret i1 %a5
}

define i1 @canonicalize_or_sadd_with_overflow_icmp_overflow(i32 %a0) {
; CHECK-LABEL: define i1 @canonicalize_or_sadd_with_overflow_icmp_overflow(
; CHECK-SAME: i32 [[A0:%.*]]) {
; CHECK-NEXT: [[A1:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[A0]], i32 -2147483647)
; CHECK-NEXT: [[A2:%.*]] = extractvalue { i32, i1 } [[A1]], 1
; CHECK-NEXT: [[A3:%.*]] = extractvalue { i32, i1 } [[A1]], 0
; CHECK-NEXT: [[A4:%.*]] = icmp slt i32 [[A3]], 2
; CHECK-NEXT: [[A5:%.*]] = or i1 [[A2]], [[A4]]
; CHECK-NEXT: ret i1 [[A5]]
;
%a1 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %a0, i32 -2147483647)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp slt i32 %a3, 2
%a5 = or i1 %a2, %a4
ret i1 %a5
}

define i1 @canonicalize_or_uadd_with_overflow_icmp_overflow(i32 %a0) {
; CHECK-LABEL: define i1 @canonicalize_or_uadd_with_overflow_icmp_overflow(
; CHECK-SAME: i32 [[A0:%.*]]) {
; CHECK-NEXT: [[A1:%.*]] = tail call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 [[A0]], i32 3)
; CHECK-NEXT: [[A2:%.*]] = extractvalue { i32, i1 } [[A1]], 1
; CHECK-NEXT: [[A3:%.*]] = extractvalue { i32, i1 } [[A1]], 0
; CHECK-NEXT: [[A4:%.*]] = icmp ult i32 [[A3]], 2
; CHECK-NEXT: [[A5:%.*]] = or i1 [[A2]], [[A4]]
; CHECK-NEXT: ret i1 [[A5]]
;
%a1 = tail call { i32, i1 } @llvm.uadd.with.overflow.i32(i32 %a0, i32 3)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp ult i32 %a3, 2
%a5 = or i1 %a2, %a4
ret i1 %a5
}

define i1 @canonicalize_or_ssub_with_overflow_icmp_overflow(i32 %a0) {
; CHECK-LABEL: define i1 @canonicalize_or_ssub_with_overflow_icmp_overflow(
; CHECK-SAME: i32 [[A0:%.*]]) {
; CHECK-NEXT: [[A1:%.*]] = tail call { i32, i1 } @llvm.ssub.with.overflow.i32(i32 [[A0]], i32 -2147483648)
; CHECK-NEXT: [[A2:%.*]] = extractvalue { i32, i1 } [[A1]], 1
; CHECK-NEXT: [[A3:%.*]] = extractvalue { i32, i1 } [[A1]], 0
; CHECK-NEXT: [[A4:%.*]] = icmp slt i32 [[A3]], -1
; CHECK-NEXT: [[A5:%.*]] = or i1 [[A2]], [[A4]]
; CHECK-NEXT: ret i1 [[A5]]
;
%a1 = tail call { i32, i1 } @llvm.ssub.with.overflow.i32(i32 %a0, i32 -2147483648)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp slt i32 %a3, -1
%a5 = or i1 %a2, %a4
ret i1 %a5
}

define i1 @canonicalize_or_smul_with_overflow_icmp(i32 %a0) {
; CHECK-LABEL: define i1 @canonicalize_or_smul_with_overflow_icmp(
; CHECK-SAME: i32 [[A0:%.*]]) {
; CHECK-NEXT: [[A1:%.*]] = tail call { i32, i1 } @llvm.smul.with.overflow.i32(i32 [[A0]], i32 3)
; CHECK-NEXT: [[A2:%.*]] = extractvalue { i32, i1 } [[A1]], 1
; CHECK-NEXT: [[A3:%.*]] = extractvalue { i32, i1 } [[A1]], 0
; CHECK-NEXT: [[A4:%.*]] = icmp slt i32 [[A3]], 10
; CHECK-NEXT: [[A5:%.*]] = or i1 [[A2]], [[A4]]
; CHECK-NEXT: ret i1 [[A5]]
;
%a1 = tail call { i32, i1 } @llvm.smul.with.overflow.i32(i32 %a0, i32 3)
%a2 = extractvalue { i32, i1 } %a1, 1
%a3 = extractvalue { i32, i1 } %a1, 0
%a4 = icmp slt i32 %a3, 10
%a5 = or i1 %a2, %a4
ret i1 %a5
}