Index: lib/IR/Value.cpp =================================================================== --- lib/IR/Value.cpp +++ lib/IR/Value.cpp @@ -495,17 +495,29 @@ // to a type of smaller size (or the same size), and the alignment // is at least as large as for the resulting pointer type, then // we can look through the bitcast. - if (DL) - if (const BitCastInst* BC = dyn_cast(V)) { - Type *STy = BC->getSrcTy()->getPointerElementType(), - *DTy = BC->getDestTy()->getPointerElementType(); - if (STy->isSized() && DTy->isSized() && + if (DL) { + Type *STy = nullptr, *DTy = nullptr; + Value *SrcVal = nullptr; + + if (const BitCastInst *BC = dyn_cast(V)) { + SrcVal = BC->getOperand(0); + STy = BC->getSrcTy()->getPointerElementType(); + DTy = BC->getDestTy()->getPointerElementType(); + } else if (const ConstantExpr *CE = dyn_cast(V)) { + if (CE->getOpcode() == Instruction::BitCast) { + SrcVal = CE->getOperand(0); + STy = SrcVal->getType()->getPointerElementType(); + DTy = CE->getType()->getPointerElementType(); + } + } + + if (STy && STy->isSized() && DTy->isSized() && (DL->getTypeStoreSize(STy) >= DL->getTypeStoreSize(DTy)) && (DL->getABITypeAlignment(STy) >= DL->getABITypeAlignment(DTy))) - return isDereferenceablePointer(BC->getOperand(0), DL, Visited); - } + return isDereferenceablePointer(SrcVal, DL, Visited); + } // Global variables which can't collapse to null are ok. if (const GlobalVariable *GV = dyn_cast(V)) Index: test/Transforms/LICM/constexpr.ll =================================================================== --- test/Transforms/LICM/constexpr.ll +++ test/Transforms/LICM/constexpr.ll @@ -0,0 +1,46 @@ +; RUN: opt < %s -S -basicaa -licm | FileCheck %s +; This fixes PR22460 + +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-pc-windows-msvc" + +@in = internal unnamed_addr global i32* null, align 8 +@out = internal unnamed_addr global i32* null, align 8 + +; CHECK-LABEL: @bar +; CHECK: entry: +; CHECK: load i64* bitcast (i32** @in to i64*) +; CHECK: do.body: +; CHECK-NOT: load + +define i64 @bar(i32 %N) { +entry: + br label %do.body + +do.body: ; preds = %l2, %entry + %i.0 = phi i32 [ 0, %entry ], [ %inc, %l2 ] + %total = phi i64 [ 0, %entry ], [ %next, %l2 ] + %c = icmp eq i32 %N, 6 + br i1 %c, label %l1, label %do.body.l2_crit_edge + +do.body.l2_crit_edge: ; preds = %do.body + %inval.pre = load i32** @in, align 8 + br label %l2 + +l1: ; preds = %do.body + %v1 = load i64* bitcast (i32** @in to i64*), align 8 + store i64 %v1, i64* bitcast (i32** @out to i64*), align 8 + %0 = inttoptr i64 %v1 to i32* + br label %l2 + +l2: ; preds = %do.body.l2_crit_edge, %l1 + %inval = phi i32* [ %inval.pre, %do.body.l2_crit_edge ], [ %0, %l1 ] + %int = ptrtoint i32* %inval to i64 + %next = add i64 %total, %int + %inc = add nsw i32 %i.0, 1 + %cmp = icmp slt i32 %inc, %N + br i1 %cmp, label %do.body, label %do.end + +do.end: ; preds = %l2 + ret i64 %total +}