[dev.regabi] cmd/compile: refactor abiutils from "gc" into new "abi"

Needs to be visible to ssagen, and might as well start clean to avoid
creating a lot of accidental dependencies.

Added some methods for export.

Decided to use a pointer instead of value for ABIConfig uses.

Tests ended up separate from abiutil itself; otherwise there are import cycles.

Change-Id: I5570e1e6a463e303c5e2dc84e8dd4125e7c1adcc
Reviewed-on: https://go-review.googlesource.com/c/go/+/282614
Trust: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Jeremy Faller <jeremy@golang.org>

src/cmd/compile/internal/abi/abiutils.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package gc
+package abi
 
 import (
 	"cmd/compile/internal/types"
@@ -28,7 +28,35 @@ type ABIParamResultInfo struct {
 	intSpillSlots     int
 	floatSpillSlots   int
 	offsetToSpillArea int64
-	config            ABIConfig // to enable String() method
+	config            *ABIConfig // to enable String() method
+}
+
+func (a *ABIParamResultInfo) InParams() []ABIParamAssignment {
+	return a.inparams
+}
+
+func (a *ABIParamResultInfo) OutParams() []ABIParamAssignment {
+	return a.outparams
+}
+
+func (a *ABIParamResultInfo) InParam(i int) ABIParamAssignment {
+	return a.inparams[i]
+}
+
+func (a *ABIParamResultInfo) OutParam(i int) ABIParamAssignment {
+	return a.outparams[i]
+}
+
+func (a *ABIParamResultInfo) IntSpillCount() int {
+	return a.intSpillSlots
+}
+
+func (a *ABIParamResultInfo) FloatSpillCount() int {
+	return a.floatSpillSlots
+}
+
+func (a *ABIParamResultInfo) SpillAreaOffset() int64 {
+	return a.offsetToSpillArea
 }
 
 // RegIndex stores the index into the set of machine registers used by
@@ -66,11 +94,17 @@ type ABIConfig struct {
 	regAmounts RegAmounts
 }
 
+// NewABIConfig returns a new ABI configuration for an architecture with
+// iRegsCount integer/pointer registers and fRegsCount floating point registers.
+func NewABIConfig(iRegsCount, fRegsCount int) *ABIConfig {
+	return &ABIConfig{RegAmounts{iRegsCount, fRegsCount}}
+}
+
 // ABIAnalyze takes a function type 't' and an ABI rules description
 // 'config' and analyzes the function to determine how its parameters
 // and results will be passed (in registers or on the stack), returning
 // an ABIParamResultInfo object that holds the results of the analysis.
-func ABIAnalyze(t *types.Type, config ABIConfig) ABIParamResultInfo {
+func ABIAnalyze(t *types.Type, config *ABIConfig) ABIParamResultInfo {
 	setup()
 	s := assignState{
 		rTotal: config.regAmounts,
@@ -124,7 +158,7 @@ func (c *RegAmounts) regString(r RegIndex) string {
 
 // toString method renders an ABIParamAssignment in human-readable
 // form, suitable for debugging or unit testing.
-func (ri *ABIParamAssignment) toString(config ABIConfig) string {
+func (ri *ABIParamAssignment) toString(config *ABIConfig) string {
 	regs := "R{"
 	for _, r := range ri.Registers {
 		regs += " " + config.regAmounts.regString(r)

src/cmd/compile/internal/test/abiutils_test.go

@@ -2,10 +2,11 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package gc
+package test
 
 import (
 	"bufio"
+	"cmd/compile/internal/abi"
 	"cmd/compile/internal/base"
 	"cmd/compile/internal/ssagen"
 	"cmd/compile/internal/typecheck"
@@ -20,12 +21,7 @@ import (
 // AMD64 registers available:
 // - integer: RAX, RBX, RCX, RDI, RSI, R8, R9, r10, R11
 // - floating point: X0 - X14
-var configAMD64 = ABIConfig{
-	regAmounts: RegAmounts{
-		intRegs:   9,
-		floatRegs: 15,
-	},
-}
+var configAMD64 = abi.NewABIConfig(9,15)
 
 func TestMain(m *testing.M) {
 	ssagen.Arch.LinkArch = &x86.Linkamd64

src/cmd/compile/internal/test/abiutilsaux_test.go

@@ -2,12 +2,13 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package gc
+package test
 
 // This file contains utility routines and harness infrastructure used
 // by the ABI tests in "abiutils_test.go".
 
 import (
+	"cmd/compile/internal/abi"
 	"cmd/compile/internal/ir"
 	"cmd/compile/internal/typecheck"
 	"cmd/compile/internal/types"
@@ -75,7 +76,7 @@ func tokenize(src string) []string {
 	return res
 }
 
-func verifyParamResultOffset(t *testing.T, f *types.Field, r ABIParamAssignment, which string, idx int) int {
+func verifyParamResultOffset(t *testing.T, f *types.Field, r abi.ABIParamAssignment, which string, idx int) int {
 	n := ir.AsNode(f.Nname).(*ir.Name)
 	if n.FrameOffset() != int64(r.Offset) {
 		t.Errorf("%s %d: got offset %d wanted %d t=%v",
@@ -110,7 +111,7 @@ func abitest(t *testing.T, ft *types.Type, exp expectedDump) {
 	types.CalcSize(ft)
 
 	// Analyze with full set of registers.
-	regRes := ABIAnalyze(ft, configAMD64)
+	regRes := abi.ABIAnalyze(ft, configAMD64)
 	regResString := strings.TrimSpace(regRes.String())
 
 	// Check results.
@@ -121,8 +122,8 @@ func abitest(t *testing.T, ft *types.Type, exp expectedDump) {
 	}
 
 	// Analyze again with empty register set.
-	empty := ABIConfig{}
-	emptyRes := ABIAnalyze(ft, empty)
+	empty := &abi.ABIConfig{}
+	emptyRes := abi.ABIAnalyze(ft, empty)
 	emptyResString := emptyRes.String()
 
 	// Walk the results and make sure the offsets assigned match
@@ -135,18 +136,18 @@ func abitest(t *testing.T, ft *types.Type, exp expectedDump) {
 	rfsl := ft.Recvs().Fields().Slice()
 	poff := 0
 	if len(rfsl) != 0 {
-		failed |= verifyParamResultOffset(t, rfsl[0], emptyRes.inparams[0], "receiver", 0)
+		failed |= verifyParamResultOffset(t, rfsl[0], emptyRes.InParams()[0], "receiver", 0)
 		poff = 1
 	}
 	// params
 	pfsl := ft.Params().Fields().Slice()
 	for k, f := range pfsl {
-		verifyParamResultOffset(t, f, emptyRes.inparams[k+poff], "param", k)
+		verifyParamResultOffset(t, f, emptyRes.InParams()[k+poff], "param", k)
 	}
 	// results
 	ofsl := ft.Results().Fields().Slice()
 	for k, f := range ofsl {
-		failed |= verifyParamResultOffset(t, f, emptyRes.outparams[k], "result", k)
+		failed |= verifyParamResultOffset(t, f, emptyRes.OutParams()[k], "result", k)
 	}
 
 	if failed != 0 {