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InstSelectSimple.cpp: (visitReturnInst) Add return instructions with return 

values.
X86InstrInfo.def: add LEAVE instruction.

llvm-svn: 4691
This commit is contained in:
Brian Gaeke 2002-11-11 19:37:09 +00:00
parent dd3dd4abeb
commit b2687880e2
2 changed files with 65 additions and 9 deletions
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73
llvm/lib/Target/X86/InstSelectSimple.cpp
View File

@ -326,15 +326,70 @@ ISel::visitSetCondInst (SetCondInst & I)
/// ret long, ulong : Move value into EAX/EDX (?) and return
/// ret float/double : ? Top of FP stack? XMM0?
///
void ISel::visitReturnInst(ReturnInst &I) {
if (I.getNumOperands() != 0) { // Not 'ret void'?
// Move result into a hard register... then emit a ret
visitInstruction(I); // abort
}
// Emit a simple 'ret' instruction... appending it to the end of the basic
// block
BuildMI(BB, X86::RET, 0);
void
ISel::visitReturnInst (ReturnInst & I)
{
if (I.getNumOperands () == 1)
{
unsigned val = getReg (I.getOperand (0));
unsigned operandSize =
I.getOperand (0)->getType ()->getPrimitiveSize ();
bool isFP = I.getOperand (0)->getType ()->isFloatingPoint ();
if (isFP)
{
// ret float/double: top of FP stack
// FLD <val>
switch (operandSize)
{
case 4:
BuildMI (BB, X86::FLDr4, 1, X86::NoReg).addReg (val);
break;
case 8:
BuildMI (BB, X86::FLDr8, 1, X86::NoReg).addReg (val);
break;
default:
visitInstruction (I);
break;
}
}
else
{
switch (operandSize)
{
case 1:
// ret sbyte, ubyte: Extend value into EAX and return
// MOV AL, <val>
// CBW
BuildMI (BB, X86::MOVrr8, 1, X86::AL).addReg (val);
BuildMI (BB, X86::CBW, 0);
break;
case 2:
// ret short, ushort: Extend value into EAX and return
// MOV AX, <val>
// CWDE
BuildMI (BB, X86::MOVrr16, 1, X86::AX).addReg (val);
BuildMI (BB, X86::CWDE, 0);
break;
case 4:
// ret int, uint, ptr: Move value into EAX and return
// MOV EAX, <val>
BuildMI (BB, X86::MOVrr32, 1, X86::EAX).addReg (val);
break;
case 8:
// ret long: use EAX(least significant 32 bits)/EDX (most
// significant 32)...uh, I think so Brain, but how do i call
// up the two parts of the value from inside this mouse
// cage? *zort*
default:
// abort
visitInstruction (I);
break;
}
}
}
// Emit a 'leave' and a 'ret'
BuildMI (BB, X86::LEAVE, 0);
BuildMI (BB, X86::RET, 0);
}
/// visitBranchInst - Handle conditional and unconditional branches here. Note

1
llvm/lib/Target/X86/X86InstrInfo.def
View File

@ -44,6 +44,7 @@ I(MOVrr32 , "movl", 0, 0) // R32 = R32 89/r
I(MOVir8 , "movb", 0, 0) // R8 = imm8 B0+ rb
I(MOVir16 , "movw", 0, 0) // R16 = imm16 B8+ rw
I(MOVir32 , "movl", 0, 0) // R32 = imm32 B8+ rd
I(LEAVE , "leave", 0, 0) // leave C9
// Arithmetic instructions
I(ADDrr8 , "addb", 0, 0) // R8 += R8 00/r