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Two fixes:

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* Only load incoming arguments into virtual registers once at the
    beginning of the function
  * Assign different virtual registers to each reference to constants/globals


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5088 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2002-12-16 22:54:46 +00:00
parent 3fc14c2602
commit 14aa7fe238
2 changed files with 46 additions and 42 deletions
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44
lib/Target/X86/InstSelectSimple.cpp
View File

@ -78,6 +78,27 @@ namespace {
for (Function::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I)
F->getBasicBlockList().push_back(MBBMap[I] = new MachineBasicBlock(I));
// Emit instructions to load the arguments... The function's arguments
// look like this:
//
// [EBP] -- copy of old EBP
// [EBP + 4] -- return address
// [EBP + 8] -- first argument (leftmost lexically)
//
// So we want to start with counter = 2.
//
BB = &F->front();
unsigned ArgOffset = 8;
for (Function::aiterator I = Fn.abegin(), E = Fn.aend(); I != E;
++I, ArgOffset += 4) {
unsigned Reg = getReg(*I);
// Load it out of the stack frame at EBP + 4*argPos.
// FIXME: This should load the argument of the appropriate size!!
addRegOffset(BuildMI(BB, X86::MOVmr32, 4, Reg), X86::EBP, ArgOffset);
}
// Instruction select everything except PHI nodes
visit(Fn);
@ -213,30 +234,11 @@ namespace {
//
if (Constant *C = dyn_cast<Constant>(V)) {
copyConstantToRegister(MBB, IPt, C, Reg);
RegMap.erase(V); // Assign a new name to this constant if ref'd again
} else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
// Move the address of the global into the register
BMI(MBB, IPt, X86::MOVir32, 1, Reg).addReg(GV);
} else if (Argument *A = dyn_cast<Argument>(V)) {
// Find the position of the argument in the argument list.
const Function *f = F->getFunction ();
// The function's arguments look like this:
// [EBP] -- copy of old EBP
// [EBP + 4] -- return address
// [EBP + 8] -- first argument (leftmost lexically)
// So we want to start with counter = 2.
int counter = 2, argPos = -1;
for (Function::const_aiterator ai = f->abegin (), ae = f->aend ();
ai != ae; ++ai) {
if (&(*ai) == A) {
argPos = counter;
break; // Only need to find it once. ;-)
}
++counter;
}
assert (argPos != -1
&& "Argument not found in current function's argument list");
// Load it out of the stack frame at EBP + 4*argPos.
addRegOffset(BMI(MBB, IPt, X86::MOVmr32, 4, Reg), X86::EBP, 4*argPos);
RegMap.erase(V); // Assign a new name to this address if ref'd again
}
return Reg;

44
lib/Target/X86/X86ISelSimple.cpp
View File

@ -78,6 +78,27 @@ namespace {
for (Function::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I)
F->getBasicBlockList().push_back(MBBMap[I] = new MachineBasicBlock(I));
// Emit instructions to load the arguments... The function's arguments
// look like this:
//
// [EBP] -- copy of old EBP
// [EBP + 4] -- return address
// [EBP + 8] -- first argument (leftmost lexically)
//
// So we want to start with counter = 2.
//
BB = &F->front();
unsigned ArgOffset = 8;
for (Function::aiterator I = Fn.abegin(), E = Fn.aend(); I != E;
++I, ArgOffset += 4) {
unsigned Reg = getReg(*I);
// Load it out of the stack frame at EBP + 4*argPos.
// FIXME: This should load the argument of the appropriate size!!
addRegOffset(BuildMI(BB, X86::MOVmr32, 4, Reg), X86::EBP, ArgOffset);
}
// Instruction select everything except PHI nodes
visit(Fn);
@ -213,30 +234,11 @@ namespace {
//
if (Constant *C = dyn_cast<Constant>(V)) {
copyConstantToRegister(MBB, IPt, C, Reg);
RegMap.erase(V); // Assign a new name to this constant if ref'd again
} else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
// Move the address of the global into the register
BMI(MBB, IPt, X86::MOVir32, 1, Reg).addReg(GV);
} else if (Argument *A = dyn_cast<Argument>(V)) {
// Find the position of the argument in the argument list.
const Function *f = F->getFunction ();
// The function's arguments look like this:
// [EBP] -- copy of old EBP
// [EBP + 4] -- return address
// [EBP + 8] -- first argument (leftmost lexically)
// So we want to start with counter = 2.
int counter = 2, argPos = -1;
for (Function::const_aiterator ai = f->abegin (), ae = f->aend ();
ai != ae; ++ai) {
if (&(*ai) == A) {
argPos = counter;
break; // Only need to find it once. ;-)
}
++counter;
}
assert (argPos != -1
&& "Argument not found in current function's argument list");
// Load it out of the stack frame at EBP + 4*argPos.
addRegOffset(BMI(MBB, IPt, X86::MOVmr32, 4, Reg), X86::EBP, 4*argPos);
RegMap.erase(V); // Assign a new name to this address if ref'd again
}
return Reg;