2 files changed, 25 insertions, 6 deletions
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
index 211358ad66c..ee60c8f3a7a 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
@@ -267,12 +267,11 @@ bool WebAssemblyAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
   if (AsmVariant != 0)
     report_fatal_error("There are no defined alternate asm variants");
 
-  if (!ExtraCode) {
-    // TODO: For now, we just hard-code 0 as the constant offset; teach
-    // SelectInlineAsmMemoryOperand how to do address mode matching.
-    OS << "0(" + regToString(MI->getOperand(OpNo)) + ')';
-    return false;
-  }
+  // The current approach to inline asm is that "r" constraints are expressed
+  // as local indices, rather than values on the operand stack. This simplifies
+  // using "r" as it eliminates the need to push and pop the values in a
+  // particular order, however it also makes it impossible to have an "m"
+  // constraint. So we don't support it.
 
   return AsmPrinter::PrintAsmMemoryOperand(MI, OpNo, AsmVariant, ExtraCode, OS);
 }
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyExplicitLocals.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyExplicitLocals.cpp
index 41249117ae0..e2edb924d4d 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyExplicitLocals.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyExplicitLocals.cpp
@@ -294,6 +294,17 @@ bool WebAssemblyExplicitLocals::runOnMachineFunction(MachineFunction &MF) {
 
         unsigned OldReg = MO.getReg();
 
+        // Inline asm may have a def in the middle of the operands. Our contract
+        // with inline asm register operands is to provide local indices as
+        // immediates.
+        if (MO.isDef()) {
+          assert(MI.getOpcode() == TargetOpcode::INLINEASM);
+          unsigned LocalId = getLocalId(Reg2Local, CurLocal, OldReg);
+          MRI.removeRegOperandFromUseList(&MO);
+          MO = MachineOperand::CreateImm(LocalId);
+          continue;
+        }
+
         // If we see a stackified register, prepare to insert subsequent
         // get_locals before the start of its tree.
         if (MFI.isVRegStackified(OldReg)) {
@@ -301,6 +312,15 @@ bool WebAssemblyExplicitLocals::runOnMachineFunction(MachineFunction &MF) {
           continue;
         }
 
+        // Our contract with inline asm register operands is to provide local
+        // indices as immediates.
+        if (MI.getOpcode() == TargetOpcode::INLINEASM) {
+          unsigned LocalId = getLocalId(Reg2Local, CurLocal, OldReg);
+          MRI.removeRegOperandFromUseList(&MO);
+          MO = MachineOperand::CreateImm(LocalId);
+          continue;
+        }
+
         // Insert a get_local.
         unsigned LocalId = getLocalId(Reg2Local, CurLocal, OldReg);
         const TargetRegisterClass *RC = MRI.getRegClass(OldReg);