[ARM] GlobalISel: Lower double precision FP args

For the hard float calling convention, we just use the D registers.

For the soft-fp calling convention, we use the R registers and move values
to/from the D registers by means of G_SEQUENCE/G_EXTRACT. While doing so, we
make sure to honor the endianness of the target, since the CCAssignFn doesn't do
that for us.

For pure soft float targets, we still bail out because we don't support the
libcalls yet.

llvm-svn: 295295

1 files changed, 10 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp b/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp
index 2d6f7d23e3b..90427b27cd0 100644
--- a/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp
@@ -132,8 +132,16 @@ bool CallLowering::handleAssignments(MachineIRBuilder &MIRBuilder,
       return false;
   }
 
-  for (unsigned i = 0, e = Args.size(); i != e; ++i) {
-    CCValAssign &VA = ArgLocs[i];
+  for (unsigned i = 0, e = Args.size(), j = 0; i != e; ++i, ++j) {
+    assert(j < ArgLocs.size() && "Skipped too many arg locs");
+
+    CCValAssign &VA = ArgLocs[j];
+    assert(VA.getValNo() == i && "Location doesn't correspond to current arg");
+
+    if (VA.needsCustom()) {
+      j += Handler.assignCustomValue(Args[i], makeArrayRef(ArgLocs).slice(j));
+      continue;
+    }
 
     if (VA.isRegLoc())
       Handler.assignValueToReg(Args[i].Reg, VA.getLocReg(), VA);