From: Austin Clements <austin@google.com>
Date: Wed, 31 Mar 2021 21:41:07 +0000 (-0400)
Subject: cmd/compile: fix outgoing calls with GOEXPERIMENT=regabiargs
X-Git-Tag: go1.17beta1~896
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=1f29e69bad3673aa4f9d1c4d1016170b9ced634a;p=gostls13.git

cmd/compile: fix outgoing calls with GOEXPERIMENT=regabiargs

The logic for constructing calls in (*state).call is based around
targeted experiments with register-based calls. However, when the
register ABI is turned on everywhere, it currently doesn't account for
direct calls to non-ABIInternal functions. This CL adds a much simpler
path to (*state).call when regabiargs is turned on that looks at the
ABI of the target function.

For #40724.

Change-Id: I7f4f5fed8a5ec131bcf1ce5b9d94d45672a304cb
Reviewed-on: https://go-review.googlesource.com/c/go/+/306410
Trust: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
---

diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
index aaea732057..9c1c493233 100644
--- a/src/cmd/compile/internal/ssagen/ssa.go
+++ b/src/cmd/compile/internal/ssagen/ssa.go
@@ -4851,24 +4851,27 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val
 	var codeptr *ssa.Value // ptr to target code (if dynamic)
 	var rcvr *ssa.Value    // receiver to set
 	fn := n.X
-	var ACArgs []*types.Type       // AuxCall args
-	var ACResults []*types.Type    // AuxCall results
-	var callArgs []*ssa.Value      // For late-expansion, the args themselves (not stored, args to the call instead).
-	inRegistersForTesting := false // If a call uses register ABI for one of the testing reasons, pragma, magic types, magic names
+	var ACArgs []*types.Type    // AuxCall args
+	var ACResults []*types.Type // AuxCall results
+	var callArgs []*ssa.Value   // For late-expansion, the args themselves (not stored, args to the call instead).
 
-	var magicFnNameSym *types.Sym
-	if fn.Name() != nil {
-		magicFnNameSym = fn.Name().Sym()
-		ss := magicFnNameSym.Name
-		if strings.HasSuffix(ss, magicNameDotSuffix) {
-			inRegistersForTesting = true
+	callABI := s.f.ABIDefault
+
+	if !objabi.Experiment.RegabiArgs {
+		var magicFnNameSym *types.Sym
+		if fn.Name() != nil {
+			magicFnNameSym = fn.Name().Sym()
+			ss := magicFnNameSym.Name
+			if strings.HasSuffix(ss, magicNameDotSuffix) {
+				callABI = s.f.ABI1
+			}
 		}
-	}
-	if magicFnNameSym == nil && n.Op() == ir.OCALLINTER {
-		magicFnNameSym = fn.(*ir.SelectorExpr).Sym()
-		ss := magicFnNameSym.Name
-		if strings.HasSuffix(ss, magicNameDotSuffix[1:]) {
-			inRegistersForTesting = true
+		if magicFnNameSym == nil && n.Op() == ir.OCALLINTER {
+			magicFnNameSym = fn.(*ir.SelectorExpr).Sym()
+			ss := magicFnNameSym.Name
+			if strings.HasSuffix(ss, magicNameDotSuffix[1:]) {
+				callABI = s.f.ABI1
+			}
 		}
 	}
 
@@ -4881,10 +4884,23 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val
 		if k == callNormal && fn.Op() == ir.ONAME && fn.(*ir.Name).Class == ir.PFUNC {
 			fn := fn.(*ir.Name)
 			callee = fn
-			// TODO(register args) remove after register abi is working
-			inRegistersImported := fn.Pragma()&ir.RegisterParams != 0
-			inRegistersSamePackage := fn.Func != nil && fn.Func.Pragma&ir.RegisterParams != 0
-			inRegistersForTesting = inRegistersForTesting || inRegistersImported || inRegistersSamePackage
+			if objabi.Experiment.RegabiArgs {
+				// This is a static call, so it may be
+				// a direct call to a non-ABIInternal
+				// function. fn.Func may be nil for
+				// some compiler-generated functions,
+				// but those are all ABIInternal.
+				if fn.Func != nil {
+					callABI = abiForFunc(fn.Func, s.f.ABI0, s.f.ABI1)
+				}
+			} else {
+				// TODO(register args) remove after register abi is working
+				inRegistersImported := fn.Pragma()&ir.RegisterParams != 0
+				inRegistersSamePackage := fn.Func != nil && fn.Func.Pragma&ir.RegisterParams != 0
+				if inRegistersImported || inRegistersSamePackage {
+					callABI = s.f.ABI1
+				}
+			}
 			break
 		}
 		closure = s.expr(fn)
@@ -4909,14 +4925,11 @@ func (s *state) call(n *ir.CallExpr, k callKind, returnResultAddr bool) *ssa.Val
 		}
 	}
 
-	if regAbiForFuncType(n.X.Type().FuncType()) {
-		// Magic last type in input args to call
-		inRegistersForTesting = true
-	}
-
-	callABI := s.f.ABIDefault
-	if inRegistersForTesting {
-		callABI = s.f.ABI1
+	if !objabi.Experiment.RegabiArgs {
+		if regAbiForFuncType(n.X.Type().FuncType()) {
+			// Magic last type in input args to call
+			callABI = s.f.ABI1
+		}
 	}
 
 	params := callABI.ABIAnalyze(n.X.Type(), false /* Do not set (register) nNames from caller side -- can cause races. */)