Recommit r232027 with PR22883 fixed: Add infrastructure for support of multiple memory constraints.

The operand flag word for ISD::INLINEASM nodes now contains a 15-bit
memory constraint ID when the operand kind is Kind_Mem. This constraint
ID is a numeric equivalent to the constraint code string and is converted
with a target specific hook in TargetLowering.

This patch maps all memory constraints to InlineAsm::Constraint_m so there
is no functional change at this point. It just proves that using these
previously unused bits in the encoding of the flag word doesn't break
anything.

The next patch will make each target preserve the current mapping of
everything to Constraint_m for itself while changing the target independent
implementation of the hook to return Constraint_Unknown appropriately. Each
target will then be adapted in separate patches to use appropriate
Constraint_* values.

PR22883 was caused the matching operands copying the whole of the operand flags
for the matched operand. This included the constraint id which needed to be
replaced with the operand number. This has been fixed with a conversion
function. Following on from this, matching operands also used the operand
number as the constraint id. This has been fixed by looking up the matched
operand and taking it from there. 

llvm-svn: 232165

2 files changed, 28 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index f66e971cacb..f3641ec157d 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -6573,8 +6573,14 @@ void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) {
         // Memory output, or 'other' output (e.g. 'X' constraint).
         assert(OpInfo.isIndirect && "Memory output must be indirect operand");
 
+        unsigned ConstraintID =
+            TLI.getInlineAsmMemConstraint(OpInfo.ConstraintCode);
+        assert(ConstraintID != InlineAsm::Constraint_Unknown &&
+               "Failed to convert memory constraint code to constraint id.");
+
         // Add information to the INLINEASM node to know about this output.
         unsigned OpFlags = InlineAsm::getFlagWord(InlineAsm::Kind_Mem, 1);
+        OpFlags = InlineAsm::getFlagWordForMem(OpFlags, ConstraintID);
         AsmNodeOperands.push_back(DAG.getTargetConstant(OpFlags, MVT::i32));
         AsmNodeOperands.push_back(OpInfo.CallOperand);
         break;
@@ -6679,6 +6685,7 @@ void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) {
                "Unexpected number of operands");
         // Add information to the INLINEASM node to know about this input.
         // See InlineAsm.h isUseOperandTiedToDef.
+        OpFlag = InlineAsm::convertMemFlagWordToMatchingFlagWord(OpFlag);
         OpFlag = InlineAsm::getFlagWordForMatchingOp(OpFlag,
                                                     OpInfo.getMatchedOperand());
         AsmNodeOperands.push_back(DAG.getTargetConstant(OpFlag,
@@ -6718,8 +6725,14 @@ void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) {
         assert(InOperandVal.getValueType() == TLI.getPointerTy() &&
                "Memory operands expect pointer values");
 
+        unsigned ConstraintID =
+            TLI.getInlineAsmMemConstraint(OpInfo.ConstraintCode);
+        assert(ConstraintID != InlineAsm::Constraint_Unknown &&
+               "Failed to convert memory constraint code to constraint id.");
+
         // Add information to the INLINEASM node to know about this input.
         unsigned ResOpType = InlineAsm::getFlagWord(InlineAsm::Kind_Mem, 1);
+        ResOpType = InlineAsm::getFlagWordForMem(ResOpType, ConstraintID);
         AsmNodeOperands.push_back(DAG.getTargetConstant(ResOpType, MVT::i32));
         AsmNodeOperands.push_back(InOperandVal);
         break;
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 97abe32c972..103e1e70419 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -1779,9 +1779,23 @@ SelectInlineAsmMemoryOperands(std::vector<SDValue> &Ops) {
     } else {
       assert(InlineAsm::getNumOperandRegisters(Flags) == 1 &&
              "Memory operand with multiple values?");
+
+      unsigned TiedToOperand;
+      if (InlineAsm::isUseOperandTiedToDef(Flags, TiedToOperand)) {
+        // We need the constraint ID from the operand this is tied to.
+        unsigned CurOp = InlineAsm::Op_FirstOperand;
+        Flags = cast<ConstantSDNode>(InOps[CurOp])->getZExtValue();
+        for (; TiedToOperand; --TiedToOperand) {
+          CurOp += InlineAsm::getNumOperandRegisters(Flags)+1;
+          Flags = cast<ConstantSDNode>(InOps[CurOp])->getZExtValue();
+        }
+      }
+
       // Otherwise, this is a memory operand.  Ask the target to select it.
       std::vector<SDValue> SelOps;
-      if (SelectInlineAsmMemoryOperand(InOps[i+1], 'm', SelOps))
+      if (SelectInlineAsmMemoryOperand(InOps[i+1],
+                                       InlineAsm::getMemoryConstraintID(Flags),
+                                       SelOps))
         report_fatal_error("Could not match memory address.  Inline asm"
                            " failure!");