WebAssembly: print basic integer assembly.

Summary:
This prints assembly for int32 integer operations defined in WebAssemblyInstrInteger.td only, with major caveats:

  - The operation names are currently incorrect.
  - Other integer and floating-point types will be added later.
  - The printer isn't factored out to handle recursive AST code yet, since it can't even handle control flow anyways.
  - The assembly format isn't full s-expressions yet either, this will be added later.
  - This currently disables PrologEpilogCodeInserter as well as MachineCopyPropagation becasue they don't like virtual registers, which WebAssembly likes quite a bit. This will be fixed by factoring out NVPTX's change (currently a fork of PrologEpilogCodeInserter).

Reviewers: sunfish

Subscribers: llvm-commits, jfb

Differential Revision: http://reviews.llvm.org/D11671

llvm-svn: 243763

1 files changed, 9 insertions, 1 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
index 6f93248bd13..bac635d76fa 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
@@ -166,7 +166,15 @@ void WebAssemblyPassConfig::addPreRegAlloc() {}
 
 void WebAssemblyPassConfig::addRegAllocPasses(bool Optimized) {}
 
-void WebAssemblyPassConfig::addPostRegAlloc() {}
+void WebAssemblyPassConfig::addPostRegAlloc() {
+  // FIXME: the following passes dislike virtual registers. Disable them for now
+  //        so that basic tests can pass. Future patches will remedy this.
+  //
+  // Fails with: Regalloc must assign all vregs.
+  disablePass(&PrologEpilogCodeInserterID);
+  // Fails with: should be run after register allocation.
+  disablePass(&MachineCopyPropagationID);
+}
 
 void WebAssemblyPassConfig::addPreSched2() {}