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[InstCombine] Compare icmp inttoptr, inttoptr values directly #107012

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Merged
merged 2 commits into from
Sep 24, 2024
Merged

[InstCombine] Compare icmp inttoptr, inttoptr values directly #107012

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19be41c
[InstCombine] Add tests for fold of `icmp inttoptr, inttoptr`. NFC
citymarina Sep 6, 2024
d2ffe52
[InstCombine] Compare `icmp inttoptr, inttoptr` values directly
citymarina Sep 23, 2024
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26 changes: 21 additions & 5 deletions llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -6087,12 +6087,12 @@ Instruction *InstCombinerImpl::foldICmpWithCastOp(ICmpInst &ICmp) {

// Turn icmp (ptrtoint x), (ptrtoint/c) into a compare of the input if the
// integer type is the same size as the pointer type.
auto CompatibleSizes = [&](Type *SrcTy, Type *DestTy) {
if (isa<VectorType>(SrcTy)) {
SrcTy = cast<VectorType>(SrcTy)->getElementType();
DestTy = cast<VectorType>(DestTy)->getElementType();
auto CompatibleSizes = [&](Type *PtrTy, Type *IntTy) {
if (isa<VectorType>(PtrTy)) {
PtrTy = cast<VectorType>(PtrTy)->getElementType();
IntTy = cast<VectorType>(IntTy)->getElementType();
}
return DL.getPointerTypeSizeInBits(SrcTy) == DestTy->getIntegerBitWidth();
return DL.getPointerTypeSizeInBits(PtrTy) == IntTy->getIntegerBitWidth();
};
if (CastOp0->getOpcode() == Instruction::PtrToInt &&
CompatibleSizes(SrcTy, DestTy)) {
Expand All @@ -6109,6 +6109,22 @@ Instruction *InstCombinerImpl::foldICmpWithCastOp(ICmpInst &ICmp) {
return new ICmpInst(ICmp.getPredicate(), Op0Src, NewOp1);
}

// Do the same in the other direction for icmp (inttoptr x), (inttoptr/c).
if (CastOp0->getOpcode() == Instruction::IntToPtr &&
CompatibleSizes(DestTy, SrcTy)) {
Value *NewOp1 = nullptr;
if (auto *IntToPtrOp1 = dyn_cast<IntToPtrInst>(ICmp.getOperand(1))) {
Value *IntSrc = IntToPtrOp1->getOperand(0);
if (IntSrc->getType() == Op0Src->getType())
NewOp1 = IntToPtrOp1->getOperand(0);
} else if (auto *RHSC = dyn_cast<Constant>(ICmp.getOperand(1))) {
NewOp1 = ConstantFoldConstant(ConstantExpr::getPtrToInt(RHSC, SrcTy), DL);
}

if (NewOp1)
return new ICmpInst(ICmp.getPredicate(), Op0Src, NewOp1);
}

if (Instruction *R = foldICmpWithTrunc(ICmp))
return R;

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97 changes: 97 additions & 0 deletions llvm/test/Transforms/InstCombine/icmp-inttoptr.ll
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@@ -0,0 +1,97 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -passes=instcombine -S | FileCheck %s

declare void @use_ptr(ptr)

define i1 @inttoptr(i64 %x, i64 %y) {
; CHECK-LABEL: @inttoptr(
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i64 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: ret i1 [[CMP]]
;
%xptr = inttoptr i64 %x to ptr
%yptr = inttoptr i64 %y to ptr
%cmp = icmp eq ptr %xptr, %yptr
ret i1 %cmp
}

define i1 @inttoptr_constant(i64 %x) {
; CHECK-LABEL: @inttoptr_constant(
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i64 [[X:%.*]], 42
; CHECK-NEXT: ret i1 [[CMP]]
;
%xptr = inttoptr i64 %x to ptr
%cmp = icmp eq ptr %xptr, inttoptr (i64 42 to ptr)
ret i1 %cmp
}

define <2 x i1> @inttoptr_vector(<2 x i64> %x, <2 x i64> %y) {
; CHECK-LABEL: @inttoptr_vector(
; CHECK-NEXT: [[CMP:%.*]] = icmp eq <2 x i64> [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%xptr = inttoptr <2 x i64> %x to <2 x ptr>
%yptr = inttoptr <2 x i64> %y to <2 x ptr>
%cmp = icmp eq <2 x ptr> %xptr, %yptr
ret <2 x i1> %cmp
}

define <2 x i1> @inttoptr_vector_constant(<2 x i64> %x) {
; CHECK-LABEL: @inttoptr_vector_constant(
; CHECK-NEXT: [[CMP:%.*]] = icmp eq <2 x i64> [[X:%.*]], <i64 42, i64 123>
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%xptr = inttoptr <2 x i64> %x to <2 x ptr>
%cmp = icmp eq <2 x ptr> %xptr, inttoptr (<2 x i64> <i64 42, i64 123> to <2 x ptr>)
ret <2 x i1> %cmp
}

define i1 @inttoptr_size_mismatch(i200 %x, i64 %y) {
; CHECK-LABEL: @inttoptr_size_mismatch(
; CHECK-NEXT: [[TMP1:%.*]] = trunc i200 [[X:%.*]] to i64
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i64 [[Y:%.*]], [[TMP1]]
; CHECK-NEXT: ret i1 [[CMP]]
;
%xptr = inttoptr i200 %x to ptr
%yptr = inttoptr i64 %y to ptr
%cmp = icmp eq ptr %xptr, %yptr
ret i1 %cmp
}

define <2 x i1> @inttoptr_vector_constant_size_mismatch(<2 x i64> %x) {
; CHECK-LABEL: @inttoptr_vector_constant_size_mismatch(
; CHECK-NEXT: [[CMP:%.*]] = icmp eq <2 x i64> [[X:%.*]], <i64 42, i64 123>
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%xptr = inttoptr <2 x i64> %x to <2 x ptr>
%cmp = icmp eq <2 x ptr> %xptr, inttoptr (<2x i9> <i9 42, i9 123> to <2 x ptr>)
ret <2 x i1> %cmp
}

define i1 @inttoptr_oneside(i64 %x, ptr %y) {
; CHECK-LABEL: @inttoptr_oneside(
; CHECK-NEXT: [[XPTR:%.*]] = inttoptr i64 [[X:%.*]] to ptr
; CHECK-NEXT: [[CMP:%.*]] = icmp eq ptr [[Y:%.*]], [[XPTR]]
; CHECK-NEXT: ret i1 [[CMP]]
;
%xptr = inttoptr i64 %x to ptr
%cmp = icmp eq ptr %xptr, %y
ret i1 %cmp
}

define i1 @inttoptr_used(i64 %x, i64 %y) {
; CHECK-LABEL: @inttoptr_used(
; CHECK-NEXT: [[XPTR:%.*]] = inttoptr i64 [[X:%.*]] to ptr
; CHECK-NEXT: [[YPTR:%.*]] = inttoptr i64 [[Y:%.*]] to ptr
; CHECK-NEXT: call void @use_ptr(ptr [[XPTR]])
; CHECK-NEXT: call void @use_ptr(ptr [[YPTR]])
; CHECK-NEXT: [[CMP:%.*]] = icmp ugt i64 [[X]], [[Y]]
; CHECK-NEXT: ret i1 [[CMP]]
;
%xptr = inttoptr i64 %x to ptr
%yptr = inttoptr i64 %y to ptr
call void @use_ptr(ptr %xptr)
call void @use_ptr(ptr %yptr)
%cmp = icmp ugt ptr %xptr, %yptr
ret i1 %cmp
}

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