Index: include/llvm/CodeGen/TargetLowering.h =================================================================== --- include/llvm/CodeGen/TargetLowering.h +++ include/llvm/CodeGen/TargetLowering.h @@ -3538,6 +3538,15 @@ return false; } + /// For some targets, an LLVM type must be broken down into multiple + /// smaller types. Usually the halves are ordered according to the endianness + /// but for some platform that would break. So this method will default to + /// matching the endianness but can be overridden. + virtual bool + shouldSplitFunctionArgumentsAsLittleEndian(const DataLayout &DL) const { + return DL.isLittleEndian(); + } + /// Returns a 0 terminated array of registers that can be safely used as /// scratch registers. virtual const MCPhysReg *getScratchRegisters(CallingConv::ID CC) const { Index: lib/CodeGen/SelectionDAG/TargetLowering.cpp =================================================================== --- lib/CodeGen/SelectionDAG/TargetLowering.cpp +++ lib/CodeGen/SelectionDAG/TargetLowering.cpp @@ -5846,7 +5846,7 @@ // being a legal type for the architecture and thus has to be split to // two arguments. SDValue Ret; - if (DAG.getDataLayout().isLittleEndian()) { + if (shouldSplitFunctionArgumentsAsLittleEndian(DAG.getDataLayout())) { // Halves of WideVT are packed into registers in different order // depending on platform endianness. This is usually handled by // the C calling convention, but we can't defer to it in Index: lib/Target/AVR/AVRISelLowering.h =================================================================== --- lib/Target/AVR/AVRISelLowering.h +++ lib/Target/AVR/AVRISelLowering.h @@ -128,6 +128,11 @@ unsigned getRegisterByName(const char* RegName, EVT VT, SelectionDAG &DAG) const override; + bool shouldSplitFunctionArgumentsAsLittleEndian(const DataLayout &DL) + const override { + return false; + } + private: SDValue getAVRCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC, SDValue &AVRcc, SelectionDAG &DAG, SDLoc dl) const; Index: test/CodeGen/AVR/umul.with.overflow.i16-bug.ll =================================================================== --- /dev/null +++ test/CodeGen/AVR/umul.with.overflow.i16-bug.ll @@ -0,0 +1,49 @@ +; RUN: llc -O1 < %s -march=avr | FileCheck %s + +target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-apple-macosx10.9" + +%Vs6UInt16 = type <{ i16 }> +%Sb = type <{ i1 }> + +define hidden void @setServoAngle(i16) { + ; CHECK-LABEL: entry +entry: + %adjustedAngle = alloca %Vs6UInt16, align 2 + %1 = bitcast %Vs6UInt16* %adjustedAngle to i8* + %adjustedAngle._value = getelementptr inbounds %Vs6UInt16, %Vs6UInt16* %adjustedAngle, i32 0, i32 0 + store i16 %0, i16* %adjustedAngle._value, align 2 + +;print(unsignedInt: adjustedAngle &* UInt16(11)) +; breaks here + %adjustedAngle._value2 = getelementptr inbounds %Vs6UInt16, %Vs6UInt16* %adjustedAngle, i32 0, i32 0 + %2 = load i16, i16* %adjustedAngle._value2, align 2 + +; CHECK: mov r22, r24 +; CHECK: mov r23, r25 + +; CHECK-DAG: ldi r20, 0 +; CHECK-DAG: ldi r21, 0 +; CHECK-DAG: ldi r18, 11 +; CHECK-DAG: ldi r19, 0 + +; CHECK: mov r24, r20 +; CHECK: mov r25, r21 +; CHECK: call __mulsi3 + %3 = call { i16, i1 } @llvm.umul.with.overflow.i16(i16 %2, i16 11) + %4 = extractvalue { i16, i1 } %3, 0 + %5 = extractvalue { i16, i1 } %3, 1 + + ; above code looks fine, how is it lowered? + %6 = call i1 @printDefaultParam() + call void @print(i16 %4, i1 %6) + +; CHECK: ret + ret void +} + +declare void @print(i16, i1) +declare i1 @printDefaultParam() + +; Function Attrs: nounwind readnone speculatable +declare { i16, i1 } @llvm.umul.with.overflow.i16(i16, i16)