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[InstSimplify] Fold ptrtoint(ptradd(P,X-ptrtoint(P))) to X #98649

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Merged
nikic merged 1 commit into from
Jul 15, 2024
Merged

[InstSimplify] Fold ptrtoint(ptradd(P,X-ptrtoint(P))) to X #98649

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8 changes: 8 additions & 0 deletions llvm/lib/Analysis/InstructionSimplify.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -5333,6 +5333,14 @@ static Value *simplifyCastInst(unsigned CastOpc, Value *Op, Type *Ty,
if (Op->getType() == Ty)
return Op;

// ptrtoint (ptradd (Ptr, X - ptrtoint(Ptr))) -> X
Value *Ptr, *X;
if (CastOpc == Instruction::PtrToInt &&
match(Op, m_PtrAdd(m_Value(Ptr),
m_Sub(m_Value(X), m_PtrToInt(m_Deferred(Ptr))))) &&
X->getType() == Ty && Ty == Q.DL.getIndexType(Ptr->getType()))
return X;

return nullptr;
}

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12 changes: 2 additions & 10 deletions llvm/test/Transforms/InstSimplify/ptrtoint.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -4,11 +4,7 @@
define i64 @ptrtoint_gep_sub(ptr %ptr, i64 %end.addr) {
; CHECK-LABEL: define i64 @ptrtoint_gep_sub(
; CHECK-SAME: ptr [[PTR:%.*]], i64 [[END_ADDR:%.*]]) {
; CHECK-NEXT: [[PTR_ADDR:%.*]] = ptrtoint ptr [[PTR]] to i64
; CHECK-NEXT: [[SIZE:%.*]] = sub i64 [[END_ADDR]], [[PTR_ADDR]]
; CHECK-NEXT: [[END:%.*]] = getelementptr i8, ptr [[PTR]], i64 [[SIZE]]
; CHECK-NEXT: [[END_ADDR2:%.*]] = ptrtoint ptr [[END]] to i64
; CHECK-NEXT: ret i64 [[END_ADDR2]]
; CHECK-NEXT: ret i64 [[END_ADDR]]
;
%ptr.addr = ptrtoint ptr %ptr to i64
%size = sub i64 %end.addr, %ptr.addr
Expand All @@ -20,11 +16,7 @@ define i64 @ptrtoint_gep_sub(ptr %ptr, i64 %end.addr) {
define <2 x i64> @ptrtoint_gep_sub_vector(<2 x ptr> %ptr, <2 x i64> %end.addr) {
; CHECK-LABEL: define <2 x i64> @ptrtoint_gep_sub_vector(
; CHECK-SAME: <2 x ptr> [[PTR:%.*]], <2 x i64> [[END_ADDR:%.*]]) {
; CHECK-NEXT: [[PTR_ADDR:%.*]] = ptrtoint <2 x ptr> [[PTR]] to <2 x i64>
; CHECK-NEXT: [[SIZE:%.*]] = sub <2 x i64> [[END_ADDR]], [[PTR_ADDR]]
; CHECK-NEXT: [[END:%.*]] = getelementptr i8, <2 x ptr> [[PTR]], <2 x i64> [[SIZE]]
; CHECK-NEXT: [[END_ADDR2:%.*]] = ptrtoint <2 x ptr> [[END]] to <2 x i64>
; CHECK-NEXT: ret <2 x i64> [[END_ADDR2]]
; CHECK-NEXT: ret <2 x i64> [[END_ADDR]]
;
%ptr.addr = ptrtoint <2 x ptr> %ptr to <2 x i64>
%size = sub <2 x i64> %end.addr, %ptr.addr
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