Passing arguments to varags functions under the SPARC v9 ABI.

Arguments after the fixed arguments never use the floating point
registers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179987 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen 2013-04-21 21:36:49 +00:00
parent 1e48093df8
commit ddb14ce76c
2 changed files with 60 additions and 0 deletions

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@ -931,6 +931,49 @@ SparcTargetLowering::getSRetArgSize(SelectionDAG &DAG, SDValue Callee) const
return getDataLayout()->getTypeAllocSize(ElementTy);
}
// Fixup floating point arguments in the ... part of a varargs call.
//
// The SPARC v9 ABI requires that floating point arguments are treated the same
// as integers when calling a varargs function. This does not apply to the
// fixed arguments that are part of the function's prototype.
//
// This function post-processes a CCValAssign array created by
// AnalyzeCallOperands().
static void fixupVariableFloatArgs(SmallVectorImpl<CCValAssign> &ArgLocs,
ArrayRef<ISD::OutputArg> Outs) {
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
const CCValAssign &VA = ArgLocs[i];
// FIXME: What about f32 arguments? C promotes them to f64 when calling
// varargs functions.
if (!VA.isRegLoc() || VA.getLocVT() != MVT::f64)
continue;
// The fixed arguments to a varargs function still go in FP registers.
if (Outs[VA.getValNo()].IsFixed)
continue;
// This floating point argument should be reassigned.
CCValAssign NewVA;
// Determine the offset into the argument array.
unsigned Offset = 8 * (VA.getLocReg() - SP::D0);
assert(Offset < 16*8 && "Offset out of range, bad register enum?");
if (Offset < 6*8) {
// This argument should go in %i0-%i5.
unsigned IReg = SP::I0 + Offset/8;
// Full register, just bitconvert into i64.
NewVA = CCValAssign::getReg(VA.getValNo(), VA.getValVT(),
IReg, MVT::i64, CCValAssign::BCvt);
} else {
// This needs to go to memory, we're out of integer registers.
NewVA = CCValAssign::getMem(VA.getValNo(), VA.getValVT(),
Offset, VA.getLocVT(), VA.getLocInfo());
}
ArgLocs[i] = NewVA;
}
}
// Lower a call for the 64-bit ABI.
SDValue
SparcTargetLowering::LowerCall_64(TargetLowering::CallLoweringInfo &CLI,
@ -954,6 +997,10 @@ SparcTargetLowering::LowerCall_64(TargetLowering::CallLoweringInfo &CLI,
// Keep stack frames 16-byte aligned.
ArgsSize = RoundUpToAlignment(ArgsSize, 16);
// Varargs calls require special treatment.
if (CLI.IsVarArg)
fixupVariableFloatArgs(ArgLocs, CLI.Outs);
// Adjust the stack pointer to make room for the arguments.
// FIXME: Use hasReservedCallFrame to avoid %sp adjustments around all calls
// with more than 6 arguments.

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@ -60,3 +60,16 @@ sw.default:
}
declare void @llvm.va_start(i8*)
@.str = private unnamed_addr constant [4 x i8] c"abc\00", align 1
; CHECK: call_1d
; The fixed-arg double goes in %d2, the second goes in %o2.
; CHECK: sethi 1048576
; CHECK: , %o2
; CHECK: , %f2
define i32 @call_1d() #0 {
entry:
%call = call double (i8*, double, ...)* @varargsfunc(i8* undef, double 1.000000e+00, double 2.000000e+00)
ret i32 1
}