ARM: teach AAPCS-VFP to deal with Cortex-M4.

Cortex-M4 only has single-precision floating point support, so any LLVM
"double" type will have been split into 2 i32s by now. Fortunately, the
consecutive-register framework turns out to be precisely what's needed to
reconstruct the double and follow AAPCS-VFP correctly!

rdar://problem/17012966

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209650 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 8 deletions

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index c181046ba2..070e929fce 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -7176,11 +7176,8 @@ TargetLowering::LowerCallTo(TargetLowering::CallLoweringInfo &CLI) const {
       }
       if (Args[i].isNest)
         Flags.setNest();
-      if (NeedsRegBlock) {
+      if (NeedsRegBlock)
         Flags.setInConsecutiveRegs();
-        if (Value == NumValues - 1)
-          Flags.setInConsecutiveRegsLast();
-      }
       Flags.setOrigAlign(OriginalAlignment);
 
       MVT PartVT = getRegisterType(CLI.RetTy->getContext(), VT);
@@ -7226,6 +7223,10 @@ TargetLowering::LowerCallTo(TargetLowering::CallLoweringInfo &CLI) const {
         else if (j != 0)
           MyFlags.Flags.setOrigAlign(1);
 
+        // Only mark the end at the last register of the last value.
+        if (NeedsRegBlock && Value == NumValues - 1 && j == NumParts - 1)
+          MyFlags.Flags.setInConsecutiveRegsLast();
+
         CLI.Outs.push_back(MyFlags);
         CLI.OutVals.push_back(Parts[j]);
       }
@@ -7412,11 +7413,8 @@ void SelectionDAGISel::LowerArguments(const Function &F) {
       }
       if (F.getAttributes().hasAttribute(Idx, Attribute::Nest))
         Flags.setNest();
-      if (NeedsRegBlock) {
+      if (NeedsRegBlock)
         Flags.setInConsecutiveRegs();
-        if (Value == NumValues - 1)
-          Flags.setInConsecutiveRegsLast();
-      }
       Flags.setOrigAlign(OriginalAlignment);
 
       MVT RegisterVT = TLI->getRegisterType(*CurDAG->getContext(), VT);
@@ -7429,6 +7427,11 @@ void SelectionDAGISel::LowerArguments(const Function &F) {
         // if it isn't first piece, alignment must be 1
         else if (i > 0)
           MyFlags.Flags.setOrigAlign(1);
+
+        // Only mark the end at the last register of the last value.
+        if (NeedsRegBlock && Value == NumValues - 1 && i == NumRegs - 1)
+          MyFlags.Flags.setInConsecutiveRegsLast();
+
         Ins.push_back(MyFlags);
       }
       PartBase += VT.getStoreSize();