[Wasm RyuJit] Codegen labels

src/coreclr/jit/codegenwasm.cpp

@@ -11,8 +11,8 @@
 
 void CodeGen::genMarkLabelsForCodegen()
 {
-    // TODO-WASM: serialize fgWasmControlFlow results into codegen-level metadata/labels
-    // (or use them directly and leave this empty).
+    // No work needed here for now.
+    // We mark labels as needed in genEmitStartBlock.
 }
 
 void CodeGen::genFnEpilog(BasicBlock* block)
@@ -154,7 +154,13 @@ void CodeGen::genEmitStartBlock(BasicBlock* block)
     while (!wasmControlFlowStack->Empty() && (wasmControlFlowStack->Top()->End() == cursor))
     {
         instGen(INS_end);
-        wasmControlFlowStack->Pop();
+        WasmInterval* interval = wasmControlFlowStack->Pop();
+
+        if (!interval->IsLoop() && !block->HasFlag(BBF_HAS_LABEL))
+        {
+            block->SetFlags(BBF_HAS_LABEL);
+            genDefineTempLabel(block);
+        }
     }
 
     // Push control flow for intervals that start here or earlier, and emit
@@ -179,6 +185,12 @@ void CodeGen::genEmitStartBlock(BasicBlock* block)
             wasmCursor++;
             wasmControlFlowStack->Push(interval);
 
+            if (interval->IsLoop() && !block->HasFlag(BBF_HAS_LABEL))
+            {
+                block->SetFlags(BBF_HAS_LABEL);
+                genDefineTempLabel(block);
+            }
+
             if (wasmCursor >= compiler->fgWasmIntervals->size())
             {
                 break;
@@ -349,7 +361,7 @@ void CodeGen::genTableBasedSwitch(GenTree* treeNode)
         BasicBlock* const caseTarget = desc->GetCase(caseNum)->getDestinationBlock();
         unsigned          depth      = findTargetDepth(caseTarget);
 
-        GetEmitter()->emitIns_I(INS_label, EA_4BYTE, depth);
+        GetEmitter()->emitIns_J(INS_label, EA_4BYTE, depth, caseTarget);
     }
 }
 
@@ -878,7 +890,7 @@ void CodeGen::inst_JMP(emitJumpKind jmp, BasicBlock* tgtBlock)
 {
     instruction    instr = emitter::emitJumpKindToIns(jmp);
     unsigned const depth = findTargetDepth(tgtBlock);
-    GetEmitter()->emitIns_I(instr, EA_4BYTE, depth);
+    GetEmitter()->emitIns_J(instr, EA_4BYTE, depth, tgtBlock);
 }
 
 void CodeGen::genCreateAndStoreGCInfo(unsigned codeSize, unsigned prologSize, unsigned epilogSize DEBUGARG(void* code))

src/coreclr/jit/emit.cpp

@@ -1729,6 +1729,7 @@ void* emitter::emitAllocAnyInstr(size_t sz, emitAttr opsz)
         assert(info->idFinallyCall == false);
         assert(info->idCatchRet == false);
         assert(info->idCallSig == nullptr);
+        assert(info->idTargetBlock == nullptr);
 
         info->idNum  = emitInsCount;
         info->idSize = sz;

src/coreclr/jit/emit.h

@@ -637,6 +637,7 @@ class emitter
         bool              idFinallyCall; // Branch instruction is a call to finally
         bool              idCatchRet;    // Instruction is for a catch 'return'
         CORINFO_SIG_INFO* idCallSig;     // Used to report native call site signatures to the EE
+        BasicBlock*       idTargetBlock; // Target block for branches
     };
 
 #ifdef TARGET_ARM

src/coreclr/jit/emitwasm.cpp

@@ -29,6 +29,11 @@ void emitter::emitIns(instruction ins)
 //------------------------------------------------------------------------
 // emitIns_I: Emit an instruction with an immediate operand.
 //
+// Arguments:
+//   ins      - instruction to emit
+//   attr     - emit attributes
+//   imm      - immediate value
+//
 void emitter::emitIns_I(instruction ins, emitAttr attr, cnsval_ssize_t imm)
 {
     instrDesc* id  = emitNewInstrSC(attr, imm);
@@ -41,6 +46,32 @@ void emitter::emitIns_I(instruction ins, emitAttr attr, cnsval_ssize_t imm)
     appendToCurIG(id);
 }
 
+//------------------------------------------------------------------------
+// emitIns_J: Emit a jump instruction with an immediate operand.
+//
+// Arguments:
+//   ins         - instruction to emit
+//   attr        - emit attributes
+//   imm         - immediate value (depth in control flow stack)
+//   targetBlock - block at that depth
+//
+void emitter::emitIns_J(instruction ins, emitAttr attr, cnsval_ssize_t imm, BasicBlock* targetBlock)
+{
+    instrDesc* id  = emitNewInstrSC(attr, imm);
+    insFormat  fmt = emitInsFormat(ins);
+
+    id->idIns(ins);
+    id->idInsFmt(fmt);
+
+    if (m_debugInfoSize > 0)
+    {
+        id->idDebugOnlyInfo()->idTargetBlock = targetBlock;
+    }
+
+    dispIns(id);
+    appendToCurIG(id);
+}
+
 //------------------------------------------------------------------------
 // emitIns_S: Emit a memory instruction with a stack-based address mode operand.
 //
@@ -113,14 +144,17 @@ static unsigned GetInsOpcode(instruction ins)
 size_t emitter::emitSizeOfInsDsc(instrDesc* id) const
 {
     if (emitIsSmallInsDsc(id))
+    {
         return SMALL_IDSC_SIZE;
+    }
 
     if (id->idIsLargeCns())
     {
         assert(!id->idIsLargeDsp());
         assert(!id->idIsLargeCall());
         return sizeof(instrDescCns);
     }
+
     return sizeof(instrDesc);
 }
 
@@ -304,8 +338,11 @@ size_t emitter::emitOutputInstr(insGroup* ig, instrDesc* id, BYTE** dp)
             break;
         }
         case IF_LABEL:
-            NYI_WASM("emitOutputInstr IF_LABEL");
+        {
+            cnsval_ssize_t constant = emitGetInsSC(id);
+            dst += emitOutputULEB128(dst, (uint64_t)constant);
             break;
+        }
         case IF_MEMARG:
         {
             dst += emitOutputByte(dst, opcode);
@@ -411,6 +448,20 @@ void emitter::emitDispIns(
 
     emitDispInst(ins);
 
+    auto dispJumpTargetIfAny = [this, id]() {
+        if (m_debugInfoSize > 0)
+        {
+            BasicBlock* const targetBlock = id->idDebugOnlyInfo()->idTargetBlock;
+            if (targetBlock != nullptr)
+            {
+                printf(" ;; ");
+                insGroup* const targetGroup = (insGroup*)emitCodeGetCookie(targetBlock);
+                assert(targetGroup != nullptr);
+                emitPrintLabel(targetGroup);
+            }
+        }
+    };
+
     // The reference for the following style of display is wasm-objdump output.
     //
     switch (fmt)
@@ -424,6 +475,7 @@ void emitter::emitDispIns(
         {
             cnsval_ssize_t imm = emitGetInsSC(id);
             printf(" %llu", (uint64_t)imm);
+            dispJumpTargetIfAny();
         }
         break;
 

src/coreclr/jit/emitwasm.h

@@ -18,6 +18,7 @@ void emitDispInst(instruction ins);
 public:
 void emitIns(instruction ins);
 void emitIns_I(instruction ins, emitAttr attr, cnsval_ssize_t imm);
+void emitIns_J(instruction ins, emitAttr attr, cnsval_ssize_t imm, BasicBlock* tgtBlock);
 void emitIns_S(instruction ins, emitAttr attr, int varx, int offs);
 void emitIns_R(instruction ins, emitAttr attr, regNumber reg);