diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp index 5907e21065331..5d9c5c65cf387 100644 --- a/llvm/lib/Analysis/InstructionSimplify.cpp +++ b/llvm/lib/Analysis/InstructionSimplify.cpp @@ -2176,6 +2176,20 @@ static Value *simplifyAndInst(Value *Op0, Value *Op1, const SimplifyQuery &Q, match(Op1, m_Xor(m_Specific(A), m_SpecificInt(~*C1)))) return Constant::getNullValue(Op0->getType()); + // (X <= ~Y) && (Y > ~X) --> 0 + CmpPredicate Pred0, Pred1; + if (match(Op0, + m_c_ICmp(Pred0, m_Value(X), m_c_Xor(m_Value(Y), m_AllOnes()))) && + match(Op1, m_c_ICmp(Pred1, m_Specific(Y), + m_c_Xor(m_Specific(X), m_AllOnes())))) { + if (ICmpInst::isLE(Pred0) && ICmpInst::isGT(Pred1)) + return ConstantInt::getFalse(Op0->getType()); + if (ICmpInst::isLT(Pred0) && ICmpInst::isGE(Pred1)) + return ConstantInt::getFalse(Op0->getType()); + if (ICmpInst::isLT(Pred0) && ICmpInst::isGT(Pred1)) + return ConstantInt::getFalse(Op0->getType()); + } + if (Op0->getType()->isIntOrIntVectorTy(1)) { if (std::optional Implied = isImpliedCondition(Op0, Op1, Q.DL)) { // If Op0 is true implies Op1 is true, then Op0 is a subset of Op1. diff --git a/llvm/test/Transforms/InstCombine/and-comparison-not-always-false.ll b/llvm/test/Transforms/InstCombine/and-comparison-not-always-false.ll new file mode 100644 index 0000000000000..0ed39decf578c --- /dev/null +++ b/llvm/test/Transforms/InstCombine/and-comparison-not-always-false.ll @@ -0,0 +1,138 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5 +; RUN: opt < %s -passes=instcombine -S | FileCheck %s +define i1 @test_pass_et(i32 %0, i32 %1) { +; CHECK-LABEL: define i1 @test_pass_et( +; CHECK-SAME: i32 [[TMP0:%.*]], i32 [[TMP1:%.*]]) { +; CHECK-NEXT: [[COMMON_RET:.*:]] +; CHECK-NEXT: ret i1 false +; +common.ret: + %2 = xor i32 %0, -1 + %3 = icmp ule i32 %1, %2 + %4 = xor i32 %1, -1 + %5 = icmp ugt i32 %0, %4 + %common.ret.op = and i1 %3, %5 + ret i1 %common.ret.op +} + +define i1 @test_pass_signed(i32 %0, i32 %1) { +; CHECK-LABEL: define i1 @test_pass_signed( +; CHECK-SAME: i32 [[TMP0:%.*]], i32 [[TMP1:%.*]]) { +; CHECK-NEXT: [[COMMON_RET:.*:]] +; CHECK-NEXT: ret i1 false +; +common.ret: + %2 = xor i32 %0, -1 + %3 = icmp sle i32 %1, %2 + %4 = xor i32 %1, -1 + %5 = icmp sgt i32 %0, %4 + %common.ret.op = and i1 %3, %5 + ret i1 %common.ret.op +} + +define i1 @test_pass_tt(i32 %0, i32 %1) { +; CHECK-LABEL: define i1 @test_pass_tt( +; CHECK-SAME: i32 [[TMP0:%.*]], i32 [[TMP1:%.*]]) { +; CHECK-NEXT: [[COMMON_RET:.*:]] +; CHECK-NEXT: ret i1 false +; +common.ret: + %2 = xor i32 %0, -1 + %3 = icmp ult i32 %1, %2 + %4 = xor i32 %1, -1 + %5 = icmp ugt i32 %0, %4 + %common.ret.op = and i1 %3, %5 + ret i1 %common.ret.op +} + +define i1 @test_pass_te(i32 %0, i32 %1) { +; CHECK-LABEL: define i1 @test_pass_te( +; CHECK-SAME: i32 [[TMP0:%.*]], i32 [[TMP1:%.*]]) { +; CHECK-NEXT: [[COMMON_RET:.*:]] +; CHECK-NEXT: ret i1 false +; +common.ret: + %2 = xor i32 %0, -1 + %3 = icmp ult i32 %1, %2 + %4 = xor i32 %1, -1 + %5 = icmp uge i32 %0, %4 + %common.ret.op = and i1 %3, %5 + ret i1 %common.ret.op +} + +define i1 @test_nopass_ee(i32 %0, i32 %1) { +; CHECK-LABEL: define i1 @test_nopass_ee( +; CHECK-SAME: i32 [[TMP0:%.*]], i32 [[TMP1:%.*]]) { +; CHECK-NEXT: [[COMMON_RET:.*:]] +; CHECK-NEXT: [[TMP2:%.*]] = xor i32 [[TMP0]], -1 +; CHECK-NEXT: [[TMP3:%.*]] = icmp ule i32 [[TMP1]], [[TMP2]] +; CHECK-NEXT: [[TMP4:%.*]] = xor i32 [[TMP1]], -1 +; CHECK-NEXT: [[TMP5:%.*]] = icmp uge i32 [[TMP0]], [[TMP4]] +; CHECK-NEXT: [[COMMON_RET_OP:%.*]] = and i1 [[TMP3]], [[TMP5]] +; CHECK-NEXT: ret i1 [[COMMON_RET_OP]] +; +common.ret: + %2 = xor i32 %0, -1 + %3 = icmp ule i32 %1, %2 + %4 = xor i32 %1, -1 + %5 = icmp uge i32 %0, %4 + %common.ret.op = and i1 %3, %5 + ret i1 %common.ret.op +} + +define i1 @test_no_change_et(i32 %0, i32 %1, i32 %2) { +; CHECK-LABEL: define i1 @test_no_change_et( +; CHECK-SAME: i32 [[TMP0:%.*]], i32 [[TMP1:%.*]], i32 [[TMP2:%.*]]) { +; CHECK-NEXT: [[COMMON_RET:.*:]] +; CHECK-NEXT: [[TMP3:%.*]] = xor i32 [[TMP0]], -1 +; CHECK-NEXT: [[TMP4:%.*]] = icmp ule i32 [[TMP1]], [[TMP3]] +; CHECK-NEXT: [[TMP5:%.*]] = icmp slt i32 [[TMP1]], 0 +; CHECK-NEXT: [[COMMON_RET_OP:%.*]] = and i1 [[TMP5]], [[TMP4]] +; CHECK-NEXT: ret i1 [[COMMON_RET_OP]] +; +common.ret: + %3 = xor i32 %0, -1 + %4 = icmp ule i32 %1, %3 + %5 = xor i32 %1, -1 + %6 = icmp ugt i32 %1, %5 + %common.ret.op = and i1 %6, %4 + ret i1 %common.ret.op +} + +define i1 @test_no_change_te(i32 %0, i32 %1, i32 %2) { +; CHECK-LABEL: define i1 @test_no_change_te( +; CHECK-SAME: i32 [[TMP0:%.*]], i32 [[TMP1:%.*]], i32 [[TMP2:%.*]]) { +; CHECK-NEXT: [[COMMON_RET:.*:]] +; CHECK-NEXT: [[TMP3:%.*]] = xor i32 [[TMP0]], -1 +; CHECK-NEXT: [[TMP4:%.*]] = icmp ult i32 [[TMP1]], [[TMP3]] +; CHECK-NEXT: [[TMP5:%.*]] = icmp slt i32 [[TMP1]], 0 +; CHECK-NEXT: [[COMMON_RET_OP:%.*]] = and i1 [[TMP5]], [[TMP4]] +; CHECK-NEXT: ret i1 [[COMMON_RET_OP]] +; +common.ret: + %3 = xor i32 %0, -1 + %4 = icmp ult i32 %1, %3 + %5 = xor i32 %1, -1 + %6 = icmp uge i32 %1, %5 + %common.ret.op = and i1 %6, %4 + ret i1 %common.ret.op +} + +define i1 @test_no_change_tt(i32 %0, i32 %1, i32 %2) { +; CHECK-LABEL: define i1 @test_no_change_tt( +; CHECK-SAME: i32 [[TMP0:%.*]], i32 [[TMP1:%.*]], i32 [[TMP2:%.*]]) { +; CHECK-NEXT: [[COMMON_RET:.*:]] +; CHECK-NEXT: [[TMP3:%.*]] = xor i32 [[TMP0]], -1 +; CHECK-NEXT: [[TMP4:%.*]] = icmp ult i32 [[TMP1]], [[TMP3]] +; CHECK-NEXT: [[TMP5:%.*]] = icmp slt i32 [[TMP1]], 0 +; CHECK-NEXT: [[COMMON_RET_OP:%.*]] = and i1 [[TMP5]], [[TMP4]] +; CHECK-NEXT: ret i1 [[COMMON_RET_OP]] +; +common.ret: + %3 = xor i32 %0, -1 + %4 = icmp ult i32 %1, %3 + %5 = xor i32 %1, -1 + %6 = icmp ugt i32 %1, %5 + %common.ret.op = and i1 %6, %4 + ret i1 %common.ret.op +}