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, 33 insertions, 0 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrControl.td b/llvm/lib/Target/WebAssembly/WebAssemblyInstrControl.td
new file mode 100644
index 00000000000..59e6e3b6711
--- /dev/null
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrControl.td
@@ -0,0 +1,33 @@
+//===- WebAssemblyInstrControl.td-WebAssembly control-flow ------*- tablegen -*-
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief WebAssembly control-flow code-gen constructs.
+///
+//===----------------------------------------------------------------------===//
+
+/*
+ * TODO(jfb): Add the following.
+ *
+ * block: a fixed-length sequence of statements
+ * if: if statement
+ * do_while: do while statement, basically a loop with a conditional branch
+ * forever: infinite loop statement (like while (1)), basically an unconditional
+ *          branch (back to the top of the loop)
+ * continue: continue to start of nested loop
+ * break: break to end from nested loop or block
+ * switch: switch statement with fallthrough
+ */
+
+let hasSideEffects = 1, isReturn = 1, isTerminator = 1, hasCtrlDep = 1,
+    isBarrier = 1 in {
+//FIXME return more than just int32.
+def RETURN : I<(outs), (ins Int32:$val), [(WebAssemblyreturn Int32:$val)]>;
+} // hasSideEffects = 1, isReturn = 1, isTerminator = 1, hasCtrlDep = 1,
+  // isBarrier = 1