Index: lib/Target/Mips/MipsISelLowering.cpp =================================================================== --- lib/Target/Mips/MipsISelLowering.cpp +++ lib/Target/Mips/MipsISelLowering.cpp @@ -4063,7 +4063,12 @@ // Create frame object. EVT PtrTy = getPointerTy(DAG.getDataLayout()); - int FI = MFI.CreateFixedObject(FrameObjSize, FrameObjOffset, true); + // Make the fixed object stored to mutable so that the load instructions + // referencing it have their memory dependencies added. + // Set the frame object as isAliased which clears the underlying objects + // vector in ScheduleDAGInstrs::buildSchedGraph() resulting in addition of all + // stores as dependencies for loads referencing this fixed object. + int FI = MFI.CreateFixedObject(FrameObjSize, FrameObjOffset, false, true); SDValue FIN = DAG.getFrameIndex(FI, PtrTy); InVals.push_back(FIN); Index: test/CodeGen/Mips/fastcc_byval.ll =================================================================== --- test/CodeGen/Mips/fastcc_byval.ll +++ test/CodeGen/Mips/fastcc_byval.ll @@ -0,0 +1,27 @@ +; RUN: llc -mtriple=mipsel-linux-gnu -O3 -relocation-model=pic < %s | FileCheck %s + +; Test that a load comes after a store to the same memory location when passing +; a byVal parameter to a function which has a fastcc function call + +%struct.str = type { i32, i32, [3 x i32*] } + +declare fastcc void @_Z1F3str(%struct.str* noalias nocapture sret %agg.result, %struct.str* byval nocapture readonly align 4 %s) + +define i32 @_Z1g3str(%struct.str* byval nocapture readonly align 4 %s) { +; CHECK-LABEL: _Z1g3str: +; CHECK: sw $7, [[OFFSET:[0-9]+]]($sp) +; CHECK: lw ${{[0-9]+}}, [[OFFSET]]($sp) +entry: + %ref.tmp = alloca %struct.str, align 4 + %0 = bitcast %struct.str* %ref.tmp to i8* + call void @llvm.lifetime.start.p0i8(i64 20, i8* nonnull %0) + call fastcc void @_Z1F3str(%struct.str* nonnull sret %ref.tmp, %struct.str* byval nonnull align 4 %s) + %cl.sroa.3.0..sroa_idx2 = getelementptr inbounds %struct.str, %struct.str* %ref.tmp, i32 0, i32 1 + %cl.sroa.3.0.copyload = load i32, i32* %cl.sroa.3.0..sroa_idx2, align 4 + call void @llvm.lifetime.end.p0i8(i64 20, i8* nonnull %0) + ret i32 %cl.sroa.3.0.copyload +} + +declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture) + +declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture) Index: test/CodeGen/Mips/o32_cc_byval.ll =================================================================== --- test/CodeGen/Mips/o32_cc_byval.ll +++ test/CodeGen/Mips/o32_cc_byval.ll @@ -243,10 +243,9 @@ ; CHECK-NEXT: lw $7, 52($sp) ; CHECK-NEXT: lw $6, 48($sp) ; CHECK-NEXT: lw $5, 44($sp) -; CHECK-NEXT: lw $4, 40($sp) ; CHECK-NEXT: lw $25, %call16(f6)($gp) ; CHECK-NEXT: jalr $25 -; CHECK-NEXT: nop +; CHECK-NEXT: lw $4, 40($sp) ; CHECK-NEXT: lw $ra, 28($sp) # 4-byte Folded Reload ; CHECK-NEXT: jr $ra ; CHECK-NEXT: addiu $sp, $sp, 32