diff options
| -rw-r--r-- | lib/Analysis/InstructionSimplify.cpp | 12 | ||||
| -rw-r--r-- | test/Transforms/InstSimplify/compare.ll | 24 |
2 files changed, 36 insertions, 0 deletions
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index 31cbbba596..6bef0aedee 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -1574,6 +1574,9 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, // 'srem x, CI2' produces (-|CI2|, |CI2|). Upper = CI2->getValue().abs(); Lower = (-Upper) + 1; + } else if (match(LHS, m_UDiv(m_ConstantInt(CI2), m_Value()))) { + // 'udiv CI2, x' produces [0, CI2]. + Upper = CI2->getValue(); } else if (match(LHS, m_UDiv(m_Value(), m_ConstantInt(CI2)))) { // 'udiv x, CI2' produces [0, UINT_MAX / CI2]. APInt NegOne = APInt::getAllOnesValue(Width); @@ -1880,6 +1883,15 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, } } + // x udiv y <=u x. + if (LBO && match(LBO, m_UDiv(m_Specific(RHS), m_Value()))) { + // icmp pred (X /u Y), X + if (Pred == ICmpInst::ICMP_UGT) + return getFalse(ITy); + if (Pred == ICmpInst::ICMP_ULE) + return getTrue(ITy); + } + if (MaxRecurse && LBO && RBO && LBO->getOpcode() == RBO->getOpcode() && LBO->getOperand(1) == RBO->getOperand(1)) { switch (LBO->getOpcode()) { diff --git a/test/Transforms/InstSimplify/compare.ll b/test/Transforms/InstSimplify/compare.ll index 3ece118902..57727c9ab7 100644 --- a/test/Transforms/InstSimplify/compare.ll +++ b/test/Transforms/InstSimplify/compare.ll @@ -300,6 +300,30 @@ define i1 @udiv2(i32 %X, i32 %Y, i32 %Z) { ; CHECK: ret i1 true } +define i1 @udiv3(i32 %X, i32 %Y) { +; CHECK: @udiv3 + %A = udiv i32 %X, %Y + %C = icmp ugt i32 %A, %X + ret i1 %C +; CHECK: ret i1 false +} + +define i1 @udiv4(i32 %X, i32 %Y) { +; CHECK: @udiv4 + %A = udiv i32 %X, %Y + %C = icmp ule i32 %A, %X + ret i1 %C +; CHECK: ret i1 true +} + +define i1 @udiv5(i32 %X) { +; CHECK: @udiv5 + %A = udiv i32 123, %X + %C = icmp ugt i32 %A, 124 + ret i1 %C +; CHECK: ret i1 false +} + define i1 @sdiv1(i32 %X) { ; CHECK: @sdiv1 %A = sdiv i32 %X, 1000000 |