[WebAssembly] Fix fast-isel lowering illegal argument and return types.

For both argument and return types, promote illegal types like i24 to i32,
and if a type can't be easily promoted, clear out the signature before
bailing out, so avoid leaving it in a partially complete state.

Fixes PR37546.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@332947 91177308-0d34-0410-b5e6-96231b3b80d8

Author: Dan Gohman

lib/Target/WebAssembly/WebAssemblyFastISel.cpp

@@ -700,14 +700,22 @@ bool WebAssemblyFastISel::fastLowerArguments() {
   MRI.addLiveIn(WebAssembly::ARGUMENTS);
 
   auto *MFI = MF->getInfo<WebAssemblyFunctionInfo>();
-  for (auto const &Arg : F->args())
-    MFI->addParam(getLegalType(getSimpleType(Arg.getType())));
+  for (auto const &Arg : F->args()) {
+    MVT::SimpleValueType ArgTy = getLegalType(getSimpleType(Arg.getType()));
+    if (ArgTy == MVT::INVALID_SIMPLE_VALUE_TYPE) {
+      MFI->clearParamsAndResults();
+      return false;
+    }
+    MFI->addParam(ArgTy);
+  }
 
   if (!F->getReturnType()->isVoidTy()) {
-    MVT::SimpleValueType RetTy = getSimpleType(F->getReturnType());
-    if (RetTy == MVT::INVALID_SIMPLE_VALUE_TYPE)
+    MVT::SimpleValueType RetTy = getLegalType(getSimpleType(F->getReturnType()));
+    if (RetTy == MVT::INVALID_SIMPLE_VALUE_TYPE) {
+      MFI->clearParamsAndResults();
       return false;
-    MFI->addResult(getLegalType(RetTy));
+    }
+    MFI->addResult(RetTy);
   }
 
   return true;

lib/Target/WebAssembly/WebAssemblyMachineFunctionInfo.h

@@ -60,6 +60,8 @@ class WebAssemblyFunctionInfo final : public MachineFunctionInfo {
   void addResult(MVT VT) { Results.push_back(VT); }
   const std::vector<MVT> &getResults() const { return Results; }
 
+  void clearParamsAndResults() { Params.clear(); Results.clear(); }
+
   void setNumLocals(size_t NumLocals) { Locals.resize(NumLocals, MVT::i32); }
   void setLocal(size_t i, MVT VT) { Locals[i] = VT; }
   void addLocal(MVT VT) { Locals.push_back(VT); }

test/CodeGen/WebAssembly/fast-isel-i24.ll

@@ -1,16 +1,28 @@
 ; RUN: llc < %s -O0
 ; PR36564
+; PR37546
 
 ; Test that fast-isel properly copes with i24 arguments and return types.
 
 target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
 target triple = "wasm32-unknown-unknown"
 
+; CHECK-LABEL: add:
+; CHECK-NEXT: .param  	i32, i32{{$}}
+; CHECK-NEXT: .result 	i32{{$}}
+; CHECK-NEXT: get_local	$push2=, 0{{$}}
+; CHECK-NEXT: get_local	$push1=, 1{{$}}
+; CHECK-NEXT: i32.add 	$push0=, $pop2, $pop1{{$}}
+; CHECK-NEXT: end_function
 define i24 @add(i24 %x, i24 %y) {
     %z = add i24 %x, %y
     ret i24 %z
 }
 
+; CHECK-LABEL: return_zero:
+; CHECK-NEXT: .result 	i32{{$}}
+; CHECK-NEXT: i32.const	$push0=, 0{{$}}
+; CHECK-NEXT: end_function
 define i24 @return_zero() {
     ret i24 0
 }

test/CodeGen/WebAssembly/fast-isel-i256.ll

@@ -0,0 +1,33 @@
+; RUN: llc < %s -O0
+; PR36564
+; PR37546
+
+; Test that fast-isel properly copes with i256 arguments and return types.
+
+target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown"
+
+; CHECK-LABEL: add:
+; CHECK-NEXT: .param      i32, i64, i64, i64, i64, i64, i64, i64, i64{{$}}
+; CHECK-NOT:  .result
+; CHECK: end_function
+define i256 @add(i256 %x, i256 %y) {
+    %z = add i256 %x, %y
+    ret i256 %z
+}
+
+; CHECK-LABEL: return_zero:
+; CHECK-NEXT: .param      i32{{$}}
+; CHECK-NOT: .result
+; CHECK: end_function
+define i256 @return_zero() {
+    ret i256 0
+}
+
+; CHECK-LABEL: return_zero_with_params:
+; CHECK-NEXT: .param      i32, f32{{$}}
+; CHECK-NOT: .result
+; CHECK: end_function
+define i256 @return_zero_with_params(float %x) {
+    ret i256 0
+}