[WebAssembly] Switch to MC for instruction printing.

This encompasses several changes which are all interconnected:
 - Use the MC framework for printing almost all instructions.
 - AsmStrings are now live.
 - This introduces an indirection between LLVM vregs and WebAssembly registers,
   and a new pass, WebAssemblyRegNumbering, for computing a basic the mapping.
   This addresses some basic issues with argument registers and unused registers.
 - The way ARGUMENT instructions are handled no longer generates redundant
   get_local+set_local for every argument.

This also changes the assembly syntax somewhat; most notably, MC's printing
use sigils on label names, so those are no longer present, and push/pop now
have a sigil to keep them unambiguous.

The usage of set_local/get_local/$push/$pop will continue to evolve
significantly. This patch is just one step of a larger change.

llvm-svn: 252858

1 files changed, 2 insertions, 6 deletions

diff --git a/llvm/test/CodeGen/WebAssembly/unused-argument.ll b/llvm/test/CodeGen/WebAssembly/unused-argument.ll
index 73e39e50388..7b4eef5e4b9 100644
--- a/llvm/test/CodeGen/WebAssembly/unused-argument.ll
+++ b/llvm/test/CodeGen/WebAssembly/unused-argument.ll
@@ -10,9 +10,7 @@ target triple = "wasm32-unknown-unknown"
 ; CHECK-NEXT: .param i32{{$}}
 ; CHECK-NEXT: .result i32{{$}}
 ; CHECK-NEXT: .local i32{{$}}
-; CHECK-NEXT: get_local push, 1{{$}}
-; CHECK-NEXT: set_local 2, pop{{$}}
-; CHECK-NEXT: return (get_local 2){{$}}
+; CHECK-NEXT: return (get_local 1){{$}}
 define i32 @unused_first(i32 %x, i32 %y) {
   ret i32 %y
 }
@@ -22,9 +20,7 @@ define i32 @unused_first(i32 %x, i32 %y) {
 ; CHECK-NEXT: .param i32{{$}}
 ; CHECK-NEXT: .result i32{{$}}
 ; CHECK-NEXT: .local i32{{$}}
-; CHECK-NEXT: get_local push, 0{{$}}
-; CHECK-NEXT: set_local 2, pop{{$}}
-; CHECK-NEXT: return (get_local 2){{$}}
+; CHECK-NEXT: return (get_local 0){{$}}
 define i32 @unused_second(i32 %x, i32 %y) {
   ret i32 %x
 }