Changes commited for Nate Begeman:
Use a PowerPC specific prolog epilog inserter to control where spilled
callee save regs are placed on the stack.
Get rid of implicit return address stack slot, save return address reg
(LR) in appropriate slot
Improve code generated for functions that don't have calls or access
globals
Note from Chris: PowerPCPEI will eventually be eliminated, once the
functionality is merged into CodeGen/PrologEpilogInserter.cpp
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15536 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPC32ISelSimple.cpp b/lib/Target/PowerPC/PPC32ISelSimple.cpp
index 8da6b9d..3527238 100644
--- a/lib/Target/PowerPC/PPC32ISelSimple.cpp
+++ b/lib/Target/PowerPC/PPC32ISelSimple.cpp
@@ -646,11 +646,8 @@
/// LoadArgumentsToVirtualRegs - Load all of the arguments to this function from
/// the stack into virtual registers.
-///
-/// FIXME: When we can calculate which args are coming in via registers
-/// source them from there instead.
void ISel::LoadArgumentsToVirtualRegs(Function &Fn) {
- unsigned ArgOffset = 20; // FIXME why is this not 24?
+ unsigned ArgOffset = 24;
unsigned GPR_remaining = 8;
unsigned FPR_remaining = 13;
unsigned GPR_idx = 0, FPR_idx = 0;
@@ -1412,8 +1409,10 @@
/// <http://developer.apple.com/documentation/DeveloperTools/Conceptual/MachORuntime/2rt_powerpc_abi/chapter_9_section_5.html>
void ISel::doCall(const ValueRecord &Ret, MachineInstr *CallMI,
const std::vector<ValueRecord> &Args, bool isVarArg) {
- // Count how many bytes are to be pushed on the stack...
- unsigned NumBytes = 0;
+ // Count how many bytes are to be pushed on the stack, including the linkage
+ // area, and parameter passing area.
+ unsigned NumBytes = 24;
+ unsigned ArgOffset = 24;
if (!Args.empty()) {
for (unsigned i = 0, e = Args.size(); i != e; ++i)
@@ -1430,12 +1429,16 @@
default: assert(0 && "Unknown class!");
}
+ // Just to be safe, we'll always reserve the full 32 bytes worth of
+ // argument passing space in case any called code gets funky on us.
+ if (NumBytes < 24 + 32) NumBytes = 24 + 32;
+
// Adjust the stack pointer for the new arguments...
- BuildMI(BB, PPC32::ADJCALLSTACKDOWN, 1).addSImm(NumBytes);
+ // These functions are automatically eliminated by the prolog/epilog pass
+ BuildMI(BB, PPC32::ADJCALLSTACKDOWN, 1).addImm(NumBytes);
// Arguments go on the stack in reverse order, as specified by the ABI.
// Offset to the paramater area on the stack is 24.
- unsigned ArgOffset = 24;
int GPR_remaining = 8, FPR_remaining = 13;
unsigned GPR_idx = 0, FPR_idx = 0;
static const unsigned GPR[] = {
@@ -1573,12 +1576,14 @@
GPR_idx++;
}
} else {
- BuildMI(BB, PPC32::ADJCALLSTACKDOWN, 1).addSImm(0);
+ BuildMI(BB, PPC32::ADJCALLSTACKDOWN, 1).addImm(0);
}
BuildMI(BB, PPC32::IMPLICIT_DEF, 0, PPC32::LR);
BB->push_back(CallMI);
- BuildMI(BB, PPC32::ADJCALLSTACKUP, 1).addSImm(NumBytes);
+
+ // These functions are automatically eliminated by the prolog/epilog pass
+ BuildMI(BB, PPC32::ADJCALLSTACKUP, 1).addImm(NumBytes);
// If there is a return value, scavenge the result from the location the call
// leaves it in...
@@ -1592,11 +1597,11 @@
// Integral results are in r3
BuildMI(BB, PPC32::OR, 2, Ret.Reg).addReg(PPC32::R3).addReg(PPC32::R3);
break;
- case cFP32: // Floating-point return values live in f1
+ case cFP32: // Floating-point return values live in f1
case cFP64:
BuildMI(BB, PPC32::FMR, 1, Ret.Reg).addReg(PPC32::F1);
break;
- case cLong: // Long values are in r3 hi:r4 lo
+ case cLong: // Long values are in r3:r4
BuildMI(BB, PPC32::OR, 2, Ret.Reg).addReg(PPC32::R3).addReg(PPC32::R3);
BuildMI(BB, PPC32::OR, 2, Ret.Reg+1).addReg(PPC32::R4).addReg(PPC32::R4);
break;