[WebAssembly] Implement tail calls and unify tablegen call classes

Summary:
Implements direct and indirect tail calls enabled by the 'tail-call'
feature in both DAG ISel and FastISel. Updates existing call tests and
adds new tests including a binary encoding test.

Reviewers: aheejin

Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62877

llvm-svn: 364445
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrCall.td b/llvm/lib/Target/WebAssembly/WebAssemblyInstrCall.td
index 190328c..bcff9f2 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrCall.td
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrCall.td
@@ -23,106 +23,110 @@
                           [(WebAssemblycallseq_end timm:$amt, timm:$amt2)]>;
 } // Uses = [SP32, SP64], Defs = [SP32, SP64], isCodeGenOnly = 1
 
-multiclass CALL<WebAssemblyRegClass vt, string prefix> {
-  defm CALL_#vt : I<(outs vt:$dst), (ins function32_op:$callee, variable_ops),
-                    (outs), (ins function32_op:$callee),
-                    [(set vt:$dst, (WebAssemblycall1 (i32 imm:$callee)))],
-                    !strconcat(prefix, "call\t$dst, $callee"),
-                    !strconcat(prefix, "call\t$callee"),
-                    0x10>;
+multiclass CALL<ValueType vt, WebAssemblyRegClass rt, string prefix,
+                list<Predicate> preds = []> {
+  defm CALL_#vt :
+    I<(outs rt:$dst), (ins function32_op:$callee, variable_ops),
+      (outs), (ins function32_op:$callee),
+      [(set (vt rt:$dst), (WebAssemblycall1 (i32 imm:$callee)))],
+      !strconcat(prefix, "call\t$dst, $callee"),
+      !strconcat(prefix, "call\t$callee"),
+      0x10>,
+    Requires<preds>;
 
   let isCodeGenOnly = 1 in
-  defm PCALL_INDIRECT_#vt : I<(outs vt:$dst), (ins I32:$callee, variable_ops),
-                              (outs), (ins I32:$callee),
-                              [(set vt:$dst, (WebAssemblycall1 I32:$callee))],
-                              "PSEUDO CALL INDIRECT\t$callee",
-                              "PSEUDO CALL INDIRECT\t$callee">;
+  defm PCALL_INDIRECT_#vt :
+    I<(outs rt:$dst), (ins I32:$callee, variable_ops),
+      (outs), (ins I32:$callee),
+      [(set (vt rt:$dst), (WebAssemblycall1 I32:$callee))],
+      "PSEUDO CALL INDIRECT\t$callee",
+      "PSEUDO CALL INDIRECT\t$callee">,
+    Requires<preds>;
 
-  defm CALL_INDIRECT_#vt : I<(outs vt:$dst),
-                             (ins TypeIndex:$type, i32imm:$flags, variable_ops),
-                             (outs), (ins TypeIndex:$type, i32imm:$flags),
-                             [],
-                             !strconcat(prefix, "call_indirect\t$dst"),
-                             !strconcat(prefix, "call_indirect\t$type"),
-                             0x11>;
-}
-
-multiclass SIMD_CALL<ValueType vt, string prefix> {
-
-  defm CALL_#vt : I<(outs V128:$dst), (ins function32_op:$callee, variable_ops),
-                    (outs), (ins function32_op:$callee),
-                    [(set (vt V128:$dst),
-                      (WebAssemblycall1 (i32 imm:$callee)))],
-                    !strconcat(prefix, "call\t$dst, $callee"),
-                    !strconcat(prefix, "call\t$callee"),
-                    0x10>,
-                  Requires<[HasSIMD128]>;
-
-  let isCodeGenOnly = 1 in
-  defm PCALL_INDIRECT_#vt : I<(outs V128:$dst),
-                              (ins I32:$callee, variable_ops),
-                              (outs), (ins I32:$callee),
-                              [(set (vt V128:$dst),
-                                    (WebAssemblycall1 I32:$callee))],
-                              "PSEUDO CALL INDIRECT\t$callee",
-                              "PSEUDO CALL INDIRECT\t$callee">,
-                              Requires<[HasSIMD128]>;
-
-  defm CALL_INDIRECT_#vt : I<(outs V128:$dst),
-                             (ins TypeIndex:$type, i32imm:$flags, variable_ops),
-                             (outs), (ins TypeIndex:$type, i32imm:$flags),
-                             [],
-                             !strconcat(prefix, "call_indirect\t$dst"),
-                             !strconcat(prefix, "call_indirect\t$type"),
-                             0x11>,
-                             Requires<[HasSIMD128]>;
+  defm CALL_INDIRECT_#vt :
+    I<(outs rt:$dst),
+      (ins TypeIndex:$type, i32imm:$flags, variable_ops),
+      (outs), (ins TypeIndex:$type, i32imm:$flags),
+      [],
+      !strconcat(prefix, "call_indirect\t$dst"),
+      !strconcat(prefix, "call_indirect\t$type"),
+      0x11>,
+    Requires<preds>;
 }
 
 let Uses = [SP32, SP64], isCall = 1 in {
-defm "" : CALL<I32, "i32.">;
-defm "" : CALL<I64, "i64.">;
-defm "" : CALL<F32, "f32.">;
-defm "" : CALL<F64, "f64.">;
-defm "" : CALL<EXCEPT_REF, "except_ref.">;
-defm "" : SIMD_CALL<v16i8, "v128.">;
-defm "" : SIMD_CALL<v8i16, "v128.">;
-defm "" : SIMD_CALL<v4i32, "v128.">;
-defm "" : SIMD_CALL<v2i64, "v128.">;
-defm "" : SIMD_CALL<v4f32, "v128.">;
-defm "" : SIMD_CALL<v2f64, "v128.">;
+defm "" : CALL<i32, I32, "i32.">;
+defm "" : CALL<i64, I64, "i64.">;
+defm "" : CALL<f32, F32, "f32.">;
+defm "" : CALL<f64, F64, "f64.">;
+defm "" : CALL<ExceptRef, EXCEPT_REF, "except_ref.", [HasExceptionHandling]>;
+defm "" : CALL<v16i8, V128, "v128.", [HasSIMD128]>;
+defm "" : CALL<v8i16, V128, "v128.", [HasSIMD128]>;
+defm "" : CALL<v4i32, V128, "v128.", [HasSIMD128]>;
+defm "" : CALL<v2i64, V128, "v128.", [HasSIMD128]>;
+defm "" : CALL<v4f32, V128, "v128.", [HasSIMD128]>;
+defm "" : CALL<v2f64, V128, "v128.", [HasSIMD128]>;
 
 let IsCanonical = 1 in {
-defm CALL_VOID : I<(outs), (ins function32_op:$callee, variable_ops),
-                   (outs), (ins function32_op:$callee),
-                   [(WebAssemblycall0 (i32 imm:$callee))],
-                   "call    \t$callee", "call\t$callee", 0x10>;
+defm CALL_VOID :
+  I<(outs), (ins function32_op:$callee, variable_ops),
+    (outs), (ins function32_op:$callee),
+    [(WebAssemblycall0 (i32 imm:$callee))],
+    "call    \t$callee", "call\t$callee", 0x10>;
+
+let isReturn = 1 in
+defm RET_CALL :
+  I<(outs), (ins function32_op:$callee, variable_ops),
+    (outs), (ins function32_op:$callee),
+    [(WebAssemblyretcall (i32 imm:$callee))],
+    "return_call    \t$callee", "return_call\t$callee", 0x12>,
+  Requires<[HasTailCall]>;
 
 let isCodeGenOnly = 1 in
-defm PCALL_INDIRECT_VOID : I<(outs), (ins I32:$callee, variable_ops),
-                             (outs), (ins I32:$callee),
-                             [(WebAssemblycall0 I32:$callee)],
-                             "PSEUDO CALL INDIRECT\t$callee",
-                             "PSEUDO CALL INDIRECT\t$callee">;
+defm PCALL_INDIRECT_VOID :
+  I<(outs), (ins I32:$callee, variable_ops),
+    (outs), (ins I32:$callee),
+    [(WebAssemblycall0 I32:$callee)],
+    "PSEUDO CALL INDIRECT\t$callee",
+    "PSEUDO CALL INDIRECT\t$callee">;
 
-defm CALL_INDIRECT_VOID : I<(outs),
-                            (ins TypeIndex:$type, i32imm:$flags,
-                              variable_ops),
-                            (outs), (ins TypeIndex:$type, i32imm:$flags),
-                            [],
-                            "call_indirect\t", "call_indirect\t$type",
-                            0x11>;
+defm CALL_INDIRECT_VOID :
+  I<(outs), (ins TypeIndex:$type, i32imm:$flags, variable_ops),
+    (outs), (ins TypeIndex:$type, i32imm:$flags),
+    [],
+    "call_indirect\t", "call_indirect\t$type",
+    0x11>;
+
+let isReturn = 1 in
+defm RET_CALL_INDIRECT :
+  I<(outs), (ins TypeIndex:$type, i32imm:$flags, variable_ops),
+    (outs), (ins TypeIndex:$type, i32imm:$flags),
+    [],
+    "return_call_indirect\t", "return_call_indirect\t$type",
+    0x13>,
+  Requires<[HasTailCall]>;
+
+let isCodeGenOnly = 1, isReturn = 1 in
+defm PRET_CALL_INDIRECT:
+    I<(outs), (ins I32:$callee, variable_ops),
+      (outs), (ins I32:$callee),
+      [(WebAssemblyretcall I32:$callee)],
+      "PSEUDO RET_CALL INDIRECT\t$callee",
+      "PSEUDO RET_CALL INDIRECT\t$callee">,
+    Requires<[HasTailCall]>;
+
 } // IsCanonical = 1
 } // Uses = [SP32,SP64], isCall = 1
 
 // Patterns for matching a direct call to a global address.
 def : Pat<(i32 (WebAssemblycall1 (WebAssemblywrapper tglobaladdr:$callee))),
-          (CALL_I32 tglobaladdr:$callee)>;
+          (CALL_i32 tglobaladdr:$callee)>;
 def : Pat<(i64 (WebAssemblycall1 (WebAssemblywrapper tglobaladdr:$callee))),
-          (CALL_I64 tglobaladdr:$callee)>;
+          (CALL_i64 tglobaladdr:$callee)>;
 def : Pat<(f32 (WebAssemblycall1 (WebAssemblywrapper tglobaladdr:$callee))),
-          (CALL_F32 tglobaladdr:$callee)>;
+          (CALL_f32 tglobaladdr:$callee)>;
 def : Pat<(f64 (WebAssemblycall1 (WebAssemblywrapper tglobaladdr:$callee))),
-          (CALL_F64 tglobaladdr:$callee)>;
+          (CALL_f64 tglobaladdr:$callee)>;
 def : Pat<(v16i8 (WebAssemblycall1 (WebAssemblywrapper tglobaladdr:$callee))),
           (CALL_v16i8 tglobaladdr:$callee)>, Requires<[HasSIMD128]>;
 def : Pat<(v8i16 (WebAssemblycall1 (WebAssemblywrapper tglobaladdr:$callee))),
@@ -137,19 +141,22 @@
           (CALL_v2f64 tglobaladdr:$callee)>, Requires<[HasSIMD128]>;
 def : Pat<(ExceptRef
            (WebAssemblycall1 (WebAssemblywrapper tglobaladdr:$callee))),
-          (CALL_EXCEPT_REF tglobaladdr:$callee)>;
+          (CALL_ExceptRef tglobaladdr:$callee)>,
+      Requires<[HasExceptionHandling]>;
 def : Pat<(WebAssemblycall0 (WebAssemblywrapper tglobaladdr:$callee)),
           (CALL_VOID tglobaladdr:$callee)>;
+def : Pat<(WebAssemblyretcall (WebAssemblywrapper tglobaladdr:$callee)),
+          (RET_CALL tglobaladdr:$callee)>, Requires<[HasTailCall]>;
 
 // Patterns for matching a direct call to an external symbol.
 def : Pat<(i32 (WebAssemblycall1 (WebAssemblywrapper texternalsym:$callee))),
-          (CALL_I32 texternalsym:$callee)>;
+          (CALL_i32 texternalsym:$callee)>;
 def : Pat<(i64 (WebAssemblycall1 (WebAssemblywrapper texternalsym:$callee))),
-          (CALL_I64 texternalsym:$callee)>;
+          (CALL_i64 texternalsym:$callee)>;
 def : Pat<(f32 (WebAssemblycall1 (WebAssemblywrapper texternalsym:$callee))),
-          (CALL_F32 texternalsym:$callee)>;
+          (CALL_f32 texternalsym:$callee)>;
 def : Pat<(f64 (WebAssemblycall1 (WebAssemblywrapper texternalsym:$callee))),
-          (CALL_F64 texternalsym:$callee)>;
+          (CALL_f64 texternalsym:$callee)>;
 def : Pat<(v16i8 (WebAssemblycall1 (WebAssemblywrapper texternalsym:$callee))),
           (CALL_v16i8 texternalsym:$callee)>, Requires<[HasSIMD128]>;
 def : Pat<(v8i16 (WebAssemblycall1 (WebAssemblywrapper texternalsym:$callee))),
@@ -164,6 +171,9 @@
           (CALL_v2f64 texternalsym:$callee)>, Requires<[HasSIMD128]>;
 def : Pat<(ExceptRef
            (WebAssemblycall1 (WebAssemblywrapper texternalsym:$callee))),
-          (CALL_EXCEPT_REF texternalsym:$callee)>;
+          (CALL_ExceptRef texternalsym:$callee)>,
+      Requires<[HasExceptionHandling]>;
 def : Pat<(WebAssemblycall0 (WebAssemblywrapper texternalsym:$callee)),
           (CALL_VOID texternalsym:$callee)>;
+def : Pat<(WebAssemblyretcall (WebAssemblywrapper texternalsym:$callee)),
+          (RET_CALL texternalsym:$callee)>, Requires<[HasTailCall]>;