Index: lib/Analysis/BasicAliasAnalysis.cpp =================================================================== --- lib/Analysis/BasicAliasAnalysis.cpp +++ lib/Analysis/BasicAliasAnalysis.cpp @@ -376,6 +376,12 @@ const GEPOperator *GEPOp = dyn_cast(Op); if (!GEPOp) { + if (auto CS = ImmutableCallSite(V)) + if (const Value *RV = CS.getReturnedArgOperand()) { + V = RV; + continue; + } + // If it's not a GEP, hand it off to SimplifyInstruction to see if it // can come up with something. This matches what GetUnderlyingObject does. if (const Instruction *I = dyn_cast(V)) @@ -817,7 +823,10 @@ uint64_t V2Size, const DataLayout &DL) { - assert(GEP1->getPointerOperand() == GEP2->getPointerOperand() && + assert(GEP1->getPointerOperand()->stripPointerCasts() == + GEP2->getPointerOperand()->stripPointerCasts() && + GEP1->getPointerOperand()->getType() == + GEP2->getPointerOperand()->getType() && "Expected GEPs with the same pointer operand"); // Try to determine whether GEP1 and GEP2 index through arrays, into structs, @@ -1075,7 +1084,10 @@ // If we know the two GEPs are based off of the exact same pointer (and not // just the same underlying object), see if that tells us anything about // the resulting pointers. - if (GEP1->getPointerOperand() == GEP2->getPointerOperand()) { + if (GEP1->getPointerOperand()->stripPointerCasts() == + GEP2->getPointerOperand()->stripPointerCasts() && + GEP1->getPointerOperand()->getType() == + GEP2->getPointerOperand()->getType()) { AliasResult R = aliasSameBasePointerGEPs(GEP1, V1Size, GEP2, V2Size, DL); // If we couldn't find anything interesting, don't abandon just yet. if (R != MayAlias) Index: lib/Analysis/ValueTracking.cpp =================================================================== --- lib/Analysis/ValueTracking.cpp +++ lib/Analysis/ValueTracking.cpp @@ -2981,6 +2981,12 @@ return V; V = GA->getAliasee(); } else { + if (auto CS = CallSite(V)) + if (Value *RV = CS.getReturnedArgOperand()) { + V = RV; + continue; + } + // See if InstructionSimplify knows any relevant tricks. if (Instruction *I = dyn_cast(V)) // TODO: Acquire a DominatorTree and AssumptionCache and use them. Index: lib/IR/Value.cpp =================================================================== --- lib/IR/Value.cpp +++ lib/IR/Value.cpp @@ -464,6 +464,12 @@ return V; V = GA->getAliasee(); } else { + if (auto CS = CallSite(V)) + if (Value *RV = CS.getReturnedArgOperand()) { + V = RV; + continue; + } + return V; } assert(V->getType()->isPointerTy() && "Unexpected operand type!"); @@ -513,6 +519,12 @@ } else if (GlobalAlias *GA = dyn_cast(V)) { V = GA->getAliasee(); } else { + if (auto CS = CallSite(V)) + if (Value *RV = CS.getReturnedArgOperand()) { + V = RV; + continue; + } + return V; } assert(V->getType()->isPointerTy() && "Unexpected operand type!"); Index: test/Analysis/BasicAA/returned.ll =================================================================== --- /dev/null +++ test/Analysis/BasicAA/returned.ll @@ -0,0 +1,45 @@ +; RUN: opt < %s -basicaa -aa-eval -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s + +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" + +%struct = type { i32, i32, i32 } + +; CHECK-LABEL: test_simple + +; CHECK-DAG: MustAlias: %struct* %st, %struct* %sta + +; CHECK-DAG: PartialAlias: %struct* %st, i32* %x +; CHECK-DAG: PartialAlias: %struct* %st, i32* %y +; CHECK-DAG: PartialAlias: %struct* %st, i32* %z + +; CHECK-DAG: NoAlias: i32* %x, i32* %y +; CHECK-DAG: NoAlias: i32* %x, i32* %z +; CHECK-DAG: NoAlias: i32* %y, i32* %z + +; CHECK-DAG: PartialAlias: %struct* %st, %struct* %y_12 +; CHECK-DAG: PartialAlias: %struct* %y_12, i32* %x +; CHECK-DAG: PartialAlias: i32* %x, i80* %y_10 + +; CHECK-DAG: PartialAlias: %struct* %st, i64* %y_8 +; CHECK-DAG: PartialAlias: i32* %z, i64* %y_8 +; CHECK-DAG: NoAlias: i32* %x, i64* %y_8 + +; CHECK-DAG: MustAlias: %struct* %y_12, i32* %y +; CHECK-DAG: MustAlias: i32* %y, i64* %y_8 +; CHECK-DAG: MustAlias: i32* %y, i80* %y_10 + +define void @test_simple(%struct* %st, i64 %i, i64 %j, i64 %k) { + %x = getelementptr %struct, %struct* %st, i64 %i, i32 0 + %y = getelementptr %struct, %struct* %st, i64 %j, i32 1 + %sta = call %struct* @func2(%struct* %st) + %z = getelementptr %struct, %struct* %sta, i64 %k, i32 2 + %y_12 = bitcast i32* %y to %struct* + %y_10 = bitcast i32* %y to i80* + %ya = call i32* @func1(i32* %y) + %y_8 = bitcast i32* %ya to i64* + ret void +} + +declare i32* @func1(i32* returned) nounwind +declare %struct* @func2(%struct* returned) nounwind +