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
diff --git a/lib/Target/Sparc/SparcISelLowering.cpp b/lib/Target/Sparc/SparcISelLowering.cpp
index e839d45..3863e2c 100644
--- a/lib/Target/Sparc/SparcISelLowering.cpp
+++ b/lib/Target/Sparc/SparcISelLowering.cpp
@@ -931,6 +931,49 @@
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 @@
// 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.