cmd/compile: remove unused arg from gorecover

We don't need this argument anymore to match up
a recover with its corresponding panic.

Change-Id: I5d3646cdd766259ee9d3d995a2f215f02e17abc6
Reviewed-on: https://go-review.googlesource.com/c/go/+/685555
Reviewed-by: Michael Knyszek <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Keith Randall <[email protected]>
Reviewed-by: Cuong Manh Le <[email protected]>

Author: randall77

src/cmd/compile/internal/escape/call.go

@@ -192,7 +192,7 @@ func (e *escape) call(ks []hole, call ir.Node) {
 		e.discard(call.X)
 		e.discard(call.Y)
 
-	case ir.ODELETE, ir.OPRINT, ir.OPRINTLN, ir.ORECOVERFP:
+	case ir.ODELETE, ir.OPRINT, ir.OPRINTLN, ir.ORECOVER:
 		call := call.(*ir.CallExpr)
 		for _, arg := range call.Args {
 			e.discard(arg)

src/cmd/compile/internal/escape/expr.go

@@ -139,7 +139,7 @@ func (e *escape) exprSkipInit(k hole, n ir.Node) {
 		e.discard(n.X)
 
 	case ir.OCALLMETH, ir.OCALLFUNC, ir.OCALLINTER, ir.OINLCALL,
-		ir.OLEN, ir.OCAP, ir.OMIN, ir.OMAX, ir.OCOMPLEX, ir.OREAL, ir.OIMAG, ir.OAPPEND, ir.OCOPY, ir.ORECOVERFP,
+		ir.OLEN, ir.OCAP, ir.OMIN, ir.OMAX, ir.OCOMPLEX, ir.OREAL, ir.OIMAG, ir.OAPPEND, ir.OCOPY, ir.ORECOVER,
 		ir.OUNSAFEADD, ir.OUNSAFESLICE, ir.OUNSAFESTRING, ir.OUNSAFESTRINGDATA, ir.OUNSAFESLICEDATA:
 		e.call([]hole{k}, n)
 

src/cmd/compile/internal/escape/stmt.go

@@ -183,7 +183,7 @@ func (e *escape) stmt(n ir.Node) {
 			dsts[i] = res.Nname.(*ir.Name)
 		}
 		e.assignList(dsts, n.Results, "return", n)
-	case ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER, ir.OINLCALL, ir.OCLEAR, ir.OCLOSE, ir.OCOPY, ir.ODELETE, ir.OPANIC, ir.OPRINT, ir.OPRINTLN, ir.ORECOVERFP:
+	case ir.OCALLFUNC, ir.OCALLMETH, ir.OCALLINTER, ir.OINLCALL, ir.OCLEAR, ir.OCLOSE, ir.OCOPY, ir.ODELETE, ir.OPANIC, ir.OPRINT, ir.OPRINTLN, ir.ORECOVER:
 		e.call(nil, n)
 	case ir.OGO, ir.ODEFER:
 		n := n.(*ir.GoDeferStmt)

src/cmd/compile/internal/inline/inl.go

@@ -605,10 +605,7 @@ opSwitch:
 		v.budget -= inlineExtraPanicCost
 
 	case ir.ORECOVER:
-		base.FatalfAt(n.Pos(), "ORECOVER missed typecheck")
-	case ir.ORECOVERFP:
-		// recover matches the argument frame pointer to find
-		// the right panic value, so it needs an argument frame.
+		// TODO: maybe we could allow inlining of recover() now?
 		v.reason = "call to recover"
 		return true
 

src/cmd/compile/internal/inline/inlheur/analyze_func_flags.go

@@ -335,7 +335,7 @@ func (ffa *funcFlagsAnalyzer) nodeVisitPost(n ir.Node) {
 		ir.OPRINTLN, ir.OPRINT, ir.OLABEL, ir.OCALLINTER, ir.ODEFER,
 		ir.OSEND, ir.ORECV, ir.OSELRECV2, ir.OGO, ir.OAPPEND, ir.OAS2DOTTYPE,
 		ir.OAS2MAPR, ir.OGETG, ir.ODELETE, ir.OINLMARK, ir.OAS2RECV,
-		ir.OMIN, ir.OMAX, ir.OMAKE, ir.ORECOVERFP, ir.OGETCALLERSP:
+		ir.OMIN, ir.OMAX, ir.OMAKE, ir.OGETCALLERSP:
 		// these should all be benign/uninteresting
 	case ir.OTAILCALL, ir.OJUMPTABLE, ir.OTYPESW:
 		// don't expect to see these at all.

src/cmd/compile/internal/ir/expr.go

@@ -213,7 +213,7 @@ func (n *CallExpr) SetOp(op Op) {
 		ODELETE,
 		OGETG, OGETCALLERSP,
 		OMAKE, OMAX, OMIN, OPRINT, OPRINTLN,
-		ORECOVER, ORECOVERFP:
+		ORECOVER:
 		n.op = op
 	}
 }

src/cmd/compile/internal/ir/node.go

@@ -234,7 +234,6 @@ const (
 	OSLICEHEADER      // sliceheader{Ptr, Len, Cap} (Ptr is unsafe.Pointer, Len is length, Cap is capacity)
 	OSTRINGHEADER     // stringheader{Ptr, Len} (Ptr is unsafe.Pointer, Len is length)
 	ORECOVER          // recover()
-	ORECOVERFP        // recover(Args) w/ explicit FP argument
 	ORECV             // <-X
 	ORUNESTR          // Type(X) (Type is string, X is rune)
 	OSELRECV2         // like OAS2: Lhs = Rhs where len(Lhs)=2, len(Rhs)=1, Rhs[0].Op = ORECV (appears as .Var of OCASE)

src/cmd/compile/internal/ir/op_string.go

@@ -25,7 +25,7 @@ func throwinit()
 func panicwrap()
 
 func gopanic(interface{})
-func gorecover(*int32) interface{}
+func gorecover() interface{}
 func goschedguarded()
 
 // Note: these declarations are just for wasm port.