Support inline asm with multiple 64bit output in 32bit GPR

Summary: Extend fix for PR34170 to support inline assembly with multiple output operands that do not naturally go in the register class it is constrained to (eg. double in a 32-bit GPR as in the PR).

Reviewers: bogner, t.p.northover, lattner, javed.absar, efriedma

Reviewed By: efriedma

Subscribers: efriedma, tra, eraman, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D45437

llvm-svn: 339225

1 files changed, 37 insertions, 16 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 80d665a64df..62ad0ec71ee 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -7776,10 +7776,29 @@ void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) {
     SDValue Val = RetValRegs.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(),
                                              Chain, &Flag, CS.getInstruction());
 
-    // FIXME: Why don't we do this for inline asms with MRVs?
-    if (CS.getType()->isSingleValueType() && CS.getType()->isSized()) {
-      EVT ResultType = TLI.getValueType(DAG.getDataLayout(), CS.getType());
-
+    llvm::Type *CSResultType = CS.getType();
+    unsigned numRet;
+    ArrayRef<Type *> ResultTypes;
+    SmallVector<SDValue, 1> ResultValues(1);
+    if (CSResultType->isSingleValueType()) {
+      numRet = 1;
+      ResultValues[0] = Val;
+      ResultTypes = makeArrayRef(CSResultType);
+    } else {
+      numRet = CSResultType->getNumContainedTypes();
+      assert(Val->getNumOperands() == numRet &&
+             "Mismatch in number of output operands in asm result");
+      ResultTypes = CSResultType->subtypes();
+      ArrayRef<SDUse> ValueUses = Val->ops();
+      ResultValues.resize(numRet);
+      std::transform(ValueUses.begin(), ValueUses.end(), ResultValues.begin(),
+                     [](const SDUse &u) -> SDValue { return u.get(); });
+    }
+    SmallVector<EVT, 1> ResultVTs(numRet);
+    for (unsigned i = 0; i < numRet; i++) {
+      EVT ResultVT = TLI.getValueType(DAG.getDataLayout(), ResultTypes[i]);
+      SDValue Val = ResultValues[i];
+      assert(ResultTypes[i]->isSized() && "Unexpected unsized type");
       // If the type of the inline asm call site return value is different but
       // has same size as the type of the asm output bitcast it.  One example
       // of this is for vectors with different width / number of elements.
@@ -7790,22 +7809,24 @@ void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) {
       // This can also happen for a return value that disagrees with the
       // register class it is put in, eg. a double in a general-purpose
       // register on a 32-bit machine.
-      if (ResultType != Val.getValueType() &&
-          ResultType.getSizeInBits() == Val.getValueSizeInBits()) {
-        Val = DAG.getNode(ISD::BITCAST, getCurSDLoc(),
-                          ResultType, Val);
-
-      } else if (ResultType != Val.getValueType() &&
-                 ResultType.isInteger() && Val.getValueType().isInteger()) {
-        // If a result value was tied to an input value, the computed result may
-        // have a wider width than the expected result.  Extract the relevant
-        // portion.
-        Val = DAG.getNode(ISD::TRUNCATE, getCurSDLoc(), ResultType, Val);
+      if (ResultVT != Val.getValueType() &&
+          ResultVT.getSizeInBits() == Val.getValueSizeInBits())
+        Val = DAG.getNode(ISD::BITCAST, getCurSDLoc(), ResultVT, Val);
+      else if (ResultVT != Val.getValueType() && ResultVT.isInteger() &&
+               Val.getValueType().isInteger()) {
+        // If a result value was tied to an input value, the computed result
+        // may have a wider width than the expected result.  Extract the
+        // relevant portion.
+        Val = DAG.getNode(ISD::TRUNCATE, getCurSDLoc(), ResultVT, Val);
       }
 
-      assert(ResultType == Val.getValueType() && "Asm result value mismatch!");
+      assert(ResultVT == Val.getValueType() && "Asm result value mismatch!");
+      ResultVTs[i] = ResultVT;
+      ResultValues[i] = Val;
     }
 
+    Val = DAG.getNode(ISD::MERGE_VALUES, getCurSDLoc(),
+                      DAG.getVTList(ResultVTs), ResultValues);
     setValue(CS.getInstruction(), Val);
     // Don't need to use this as a chain in this case.
     if (!IA->hasSideEffects() && !hasMemory && IndirectStoresToEmit.empty())