6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-09-24 23:28:41 +00:00
Code Issues Projects Releases Wiki Activity

Currently, codegen may spent some time in SDISel passes even if an entire

Browse Source 
function is successfully handled by fast-isel. That's because function
arguments are *always* handled by SDISel. Introduce FastLowerArguments to
allow each target to provide hook to handle formal argument lowering.

As a proof-of-concept, add ARMFastIsel::FastLowerArguments to handle
functions with 4 or fewer scalar integer (i8, i16, or i32) arguments. It
completely eliminates the need for SDISel for trivial functions.

rdar://13163905


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174855 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng
2013-02-11 01:27:15 +00:00
parent 5f352cc6e4
commit 092e5e7566
4 changed files with 124 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

28
lib/CodeGen/SelectionDAG/FastISel.cpp
View File

@@ -87,6 +87,27 @@ void FastISel::startNewBlock() {
LastLocalValue = EmitStartPt;
}
bool FastISel::LowerArguments() {
if (!FuncInfo.CanLowerReturn)
// Fallback to SDISel argument lowering code to deal with sret pointer
// parameter.
return false;
if (!FastLowerArguments())
return false;
// Enter non-dead arguments into ValueMap for uses in non-entry BBs.
for (Function::const_arg_iterator I = FuncInfo.Fn->arg_begin(),
E = FuncInfo.Fn->arg_end(); I != E; ++I) {
if (!I->use_empty()) {
DenseMap<const Value *, unsigned>::iterator VI = LocalValueMap.find(I);
assert(VI != LocalValueMap.end() && "Missed an argument?");
FuncInfo.ValueMap[I] = VI->second;
}
}
return true;
}
void FastISel::flushLocalValueMap() {
LocalValueMap.clear();
LastLocalValue = EmitStartPt;
@@ -836,7 +857,8 @@ FastISel::SelectInstruction(const Instruction *I) {
void
FastISel::FastEmitBranch(MachineBasicBlock *MSucc, DebugLoc DL) {
if (FuncInfo.MBB->getBasicBlock()->size() > 1 && FuncInfo.MBB->isLayoutSuccessor(MSucc)) {
if (FuncInfo.MBB->getBasicBlock()->size() > 1 &&
FuncInfo.MBB->isLayoutSuccessor(MSucc)) {
// For more accurate line information if this is the only instruction
// in the block then emit it, otherwise we have the unconditional
// fall-through case, which needs no instructions.
@@ -1067,6 +1089,10 @@ FastISel::FastISel(FunctionLoweringInfo &funcInfo,
FastISel::~FastISel() {}
bool FastISel::FastLowerArguments() {
return false;
}
unsigned FastISel::FastEmit_(MVT, MVT,
unsigned) {
return 0;