From 76c47b50e7e9f9c1a296010e6828beb613b3ffb8 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Tue, 16 May 2006 18:54:32 +0000
Subject: [PATCH] Simplify the dead argument handling code.
llvm-svn: 28334
---
llvm/lib/Target/PowerPC/PPCISelLowering.cpp | 39 ++++++---------------
1 file changed, 11 insertions(+), 28 deletions(-)
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index f16060aa576d..5ee5154bf3f8 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -761,7 +761,6 @@ static SDOperand LowerFORMAL_ARGUMENTS(SDOperand Op, SelectionDAG &DAG,
for (unsigned ArgNo = 0, e = Op.Val->getNumValues()-1; ArgNo != e; ++ArgNo) {
SDOperand ArgVal;
bool needsLoad = false;
- bool ArgLive = !Op.Val->hasNUsesOfValue(0, ArgNo);
MVT::ValueType ObjectVT = Op.getValue(ArgNo).getValueType();
unsigned ObjSize = MVT::getSizeInBits(ObjectVT)/8;
@@ -773,13 +772,6 @@ static SDOperand LowerFORMAL_ARGUMENTS(SDOperand Op, SelectionDAG &DAG,
// All int arguments reserve stack space.
ArgOffset += 4;
- if (!ArgLive) {
- if (GPR_remaining > 0) {
- --GPR_remaining;
- ++GPR_idx;
- }
- break;
- }
if (GPR_remaining > 0) {
unsigned VReg = RegMap->createVirtualRegister(&PPC::GPRCRegClass);
MF.addLiveIn(GPR[GPR_idx], VReg);
@@ -802,13 +794,6 @@ static SDOperand LowerFORMAL_ARGUMENTS(SDOperand Op, SelectionDAG &DAG,
GPR_remaining -= delta;
GPR_idx += delta;
}
- if (!ArgLive) {
- if (FPR_remaining > 0) {
- --FPR_remaining;
- ++FPR_idx;
- }
- break;
- }
if (FPR_remaining > 0) {
unsigned VReg;
if (ObjectVT == MVT::f32)
@@ -828,13 +813,6 @@ static SDOperand LowerFORMAL_ARGUMENTS(SDOperand Op, SelectionDAG &DAG,
case MVT::v8i16:
case MVT::v16i8:
// Note that vector arguments in registers don't reserve stack space.
- if (!ArgLive) {
- if (VR_remaining > 0) {
- --VR_remaining;
- ++VR_idx;
- }
- break;
- }
if (VR_remaining > 0) {
unsigned VReg = RegMap->createVirtualRegister(&PPC::VRRCRegClass);
MF.addLiveIn(VR[VR_idx], VReg);
@@ -853,14 +831,19 @@ static SDOperand LowerFORMAL_ARGUMENTS(SDOperand Op, SelectionDAG &DAG,
// We need to load the argument to a virtual register if we determined above
// that we ran out of physical registers of the appropriate type
if (needsLoad) {
- int FI = MFI->CreateFixedObject(ObjSize, CurArgOffset);
- SDOperand FIN = DAG.getFrameIndex(FI, MVT::i32);
- ArgVal = DAG.getLoad(ObjectVT, Root, FIN,
- DAG.getSrcValue(NULL));
+ // If the argument is actually used, emit a load from the right stack
+ // slot.
+ if (!Op.Val->hasNUsesOfValue(0, ArgNo)) {
+ int FI = MFI->CreateFixedObject(ObjSize, CurArgOffset);
+ SDOperand FIN = DAG.getFrameIndex(FI, MVT::i32);
+ ArgVal = DAG.getLoad(ObjectVT, Root, FIN,
+ DAG.getSrcValue(NULL));
+ } else {
+ // Don't emit a dead load.
+ ArgVal = DAG.getNode(ISD::UNDEF, ObjectVT);
+ }
}
- if (ArgVal.Val == 0)
- ArgVal = DAG.getNode(ISD::UNDEF, ObjectVT);
ArgValues.push_back(ArgVal);
}