From 2d63fbb7b1f7bbbd91f9f862946663a813e1780c Mon Sep 17 00:00:00 2001 From: Johannes Doerfert Date: Mon, 15 Jul 2019 03:24:35 +0000 Subject: [ValueTracking] Look through constant Int2Ptr/Ptr2Int expressions Summary: This is analogous to the int2ptr/ptr2int instruction handling introduced in D54956. Reviewers: fhahn, efriedma, spatel, nlopes, sanjoy, lebedev.ri Subscribers: hiraditya, bollu, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D64708 llvm-svn: 366036 --- llvm/lib/Analysis/ValueTracking.cpp | 9 +++++++++ llvm/test/Transforms/FunctionAttrs/nonnull.ll | 10 ++++++++++ 2 files changed, 19 insertions(+) (limited to 'llvm') diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index ad8034b2d7b..49a328bbc9b 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -1998,6 +1998,15 @@ bool isKnownNonZero(const Value *V, unsigned Depth, const Query &Q) { // Must be non-zero due to null test above. return true; + if (auto *CE = dyn_cast(C)) { + // See the comment for IntToPtr/PtrToInt instructions below. + if (CE->getOpcode() == Instruction::IntToPtr || + CE->getOpcode() == Instruction::PtrToInt) + if (Q.DL.getTypeSizeInBits(CE->getOperand(0)->getType()) <= + Q.DL.getTypeSizeInBits(CE->getType())) + return isKnownNonZero(CE->getOperand(0), Depth, Q); + } + // For constant vectors, check that all elements are undefined or known // non-zero to determine that the whole vector is known non-zero. if (auto *VecTy = dyn_cast(C->getType())) { diff --git a/llvm/test/Transforms/FunctionAttrs/nonnull.ll b/llvm/test/Transforms/FunctionAttrs/nonnull.ll index 7029be9691d..6c04e4907d8 100644 --- a/llvm/test/Transforms/FunctionAttrs/nonnull.ll +++ b/llvm/test/Transforms/FunctionAttrs/nonnull.ll @@ -237,4 +237,14 @@ define i32 addrspace(3)* @gep2(i32 addrspace(3)* %p) { ret i32 addrspace(3)* %q } +; CHECK: define internal nonnull i32* @f2() +define internal i32* @f2() { + ret i32* inttoptr (i64 4 to i32*) +} + +define i32* @f1() { + %c = call i32* @f2() + ret i32* %c +} + attributes #0 = { "null-pointer-is-valid"="true" } -- cgit v1.2.3