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backend: stop allocating ValueDefinitions (#2288)
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Signed-off-by: Takeshi Yoneda <[email protected]>
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@mathetake
mathetake authored Jul 10, 2024
1 parent e2db5ac commit 9a19a04
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Showing 19 changed files with 214 additions and 223 deletions.
42 changes: 15 additions & 27 deletions internal/engine/wazevo/backend/compiler.go
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Original file line number Diff line number Diff line change
Expand Up @@ -69,7 +69,7 @@ type Compiler interface {
AllocateVReg(typ ssa.Type) regalloc.VReg

// ValueDefinition returns the definition of the given value.
ValueDefinition(ssa.Value) *SSAValueDefinition
ValueDefinition(ssa.Value) SSAValueDefinition

// VRegOf returns the virtual register of the given ssa.Value.
VRegOf(value ssa.Value) regalloc.VReg
Expand All @@ -79,13 +79,13 @@ type Compiler interface {

// MatchInstr returns true if the given definition is from an instruction with the given opcode, the current group ID,
// and a refcount of 1. That means, the instruction can be merged/swapped within the current instruction group.
MatchInstr(def *SSAValueDefinition, opcode ssa.Opcode) bool
MatchInstr(def SSAValueDefinition, opcode ssa.Opcode) bool

// MatchInstrOneOf is the same as MatchInstr but for multiple opcodes. If it matches one of ssa.Opcode,
// this returns the opcode. Otherwise, this returns ssa.OpcodeInvalid.
//
// Note: caller should be careful to avoid excessive allocation on opcodes slice.
MatchInstrOneOf(def *SSAValueDefinition, opcodes []ssa.Opcode) ssa.Opcode
MatchInstrOneOf(def SSAValueDefinition, opcodes []ssa.Opcode) ssa.Opcode

// AddRelocationInfo appends the relocation information for the function reference at the current buffer offset.
AddRelocationInfo(funcRef ssa.FuncRef)
Expand Down Expand Up @@ -126,8 +126,7 @@ type compiler struct {
nextVRegID regalloc.VRegID
// ssaValueToVRegs maps ssa.ValueID to regalloc.VReg.
ssaValueToVRegs [] /* VRegID to */ regalloc.VReg
// ssaValueDefinitions maps ssa.ValueID to its definition.
ssaValueDefinitions []SSAValueDefinition
ssaValuesInfo []ssa.ValueInfo
// returnVRegs is the list of virtual registers that store the return values.
returnVRegs []regalloc.VReg
varEdges [][2]regalloc.VReg
Expand Down Expand Up @@ -204,14 +203,10 @@ func (c *compiler) setCurrentGroupID(gid ssa.InstructionGroupID) {
// assignVirtualRegisters assigns a virtual register to each ssa.ValueID Valid in the ssa.Builder.
func (c *compiler) assignVirtualRegisters() {
builder := c.ssaBuilder
refCounts := builder.ValuesInfo()
c.ssaValuesInfo = builder.ValuesInfo()

need := len(refCounts)
if need >= len(c.ssaValueToVRegs) {
c.ssaValueToVRegs = append(c.ssaValueToVRegs, make([]regalloc.VReg, need+1)...)
}
if need >= len(c.ssaValueDefinitions) {
c.ssaValueDefinitions = append(c.ssaValueDefinitions, make([]SSAValueDefinition, need+1)...)
if diff := len(c.ssaValuesInfo) - len(c.ssaValueToVRegs); diff > 0 {
c.ssaValueToVRegs = append(c.ssaValueToVRegs, make([]regalloc.VReg, diff+1)...)
}

for blk := builder.BlockIteratorReversePostOrderBegin(); blk != nil; blk = builder.BlockIteratorReversePostOrderNext() {
Expand All @@ -222,7 +217,6 @@ func (c *compiler) assignVirtualRegisters() {
typ := p.Type()
vreg := c.AllocateVReg(typ)
c.ssaValueToVRegs[pid] = vreg
c.ssaValueDefinitions[pid] = SSAValueDefinition{V: p}
c.ssaTypeOfVRegID[vreg.ID()] = p.Type()
}

Expand All @@ -235,23 +229,13 @@ func (c *compiler) assignVirtualRegisters() {
typ := r.Type()
vReg := c.AllocateVReg(typ)
c.ssaValueToVRegs[id] = vReg
c.ssaValueDefinitions[id] = SSAValueDefinition{
Instr: cur,
V: r,
RefCount: refCounts[id].RefCount,
}
c.ssaTypeOfVRegID[vReg.ID()] = ssaTyp
}
for _, r := range rs {
id := r.ID()
ssaTyp := r.Type()
vReg := c.AllocateVReg(ssaTyp)
c.ssaValueToVRegs[id] = vReg
c.ssaValueDefinitions[id] = SSAValueDefinition{
Instr: cur,
V: r,
RefCount: refCounts[id].RefCount,
}
c.ssaTypeOfVRegID[vReg.ID()] = ssaTyp
}
}
Expand Down Expand Up @@ -293,8 +277,12 @@ func (c *compiler) Init() {
}

// ValueDefinition implements Compiler.ValueDefinition.
func (c *compiler) ValueDefinition(value ssa.Value) *SSAValueDefinition {
return &c.ssaValueDefinitions[value.ID()]
func (c *compiler) ValueDefinition(value ssa.Value) SSAValueDefinition {
return SSAValueDefinition{
V: value,
Instr: c.ssaBuilder.InstructionOfValue(value),
RefCount: c.ssaValuesInfo[value.ID()].RefCount,
}
}

// VRegOf implements Compiler.VRegOf.
Expand All @@ -313,7 +301,7 @@ func (c *compiler) TypeOf(v regalloc.VReg) ssa.Type {
}

// MatchInstr implements Compiler.MatchInstr.
func (c *compiler) MatchInstr(def *SSAValueDefinition, opcode ssa.Opcode) bool {
func (c *compiler) MatchInstr(def SSAValueDefinition, opcode ssa.Opcode) bool {
instr := def.Instr
return def.IsFromInstr() &&
instr.Opcode() == opcode &&
Expand All @@ -322,7 +310,7 @@ func (c *compiler) MatchInstr(def *SSAValueDefinition, opcode ssa.Opcode) bool {
}

// MatchInstrOneOf implements Compiler.MatchInstrOneOf.
func (c *compiler) MatchInstrOneOf(def *SSAValueDefinition, opcodes []ssa.Opcode) ssa.Opcode {
func (c *compiler) MatchInstrOneOf(def SSAValueDefinition, opcodes []ssa.Opcode) ssa.Opcode {
instr := def.Instr
if !def.IsFromInstr() {
return ssa.OpcodeInvalid
Expand Down
6 changes: 3 additions & 3 deletions internal/engine/wazevo/backend/compiler_lower.go
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Original file line number Diff line number Diff line change
Expand Up @@ -152,12 +152,12 @@ func (c *compiler) lowerBlockArguments(args []ssa.Value, succ ssa.BasicBlock) {
src := args[i]

dstReg := c.VRegOf(dst)
srcDef := c.ssaValueDefinitions[src.ID()]
if srcDef.IsFromInstr() && srcDef.Instr.Constant() {
srcInstr := c.ssaBuilder.InstructionOfValue(src)
if srcInstr != nil && srcInstr.Constant() {
c.constEdges = append(c.constEdges, struct {
cInst *ssa.Instruction
dst regalloc.VReg
}{cInst: srcDef.Instr, dst: dstReg})
}{cInst: srcInstr, dst: dstReg})
} else {
srcReg := c.VRegOf(src)
// Even when the src=dst, insert the move so that we can keep such registers keep-alive.
Expand Down
3 changes: 0 additions & 3 deletions internal/engine/wazevo/backend/compiler_lower_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -57,7 +57,6 @@ func TestCompiler_lowerBlockArguments(t *testing.T) {
}

c := newCompiler(context.Background(), m, builder)
c.ssaValueDefinitions = []SSAValueDefinition{{Instr: i1}, {Instr: i2}, {Instr: f1}, {Instr: f2}}
c.ssaValueToVRegs = []regalloc.VReg{0, 1, 2, 3, 4, 5, 6, 7}
return c, []ssa.Value{i1.Return(), i2.Return(), f1.Return(), f2.Return()}, succ, func(t *testing.T) {
require.Equal(t, 4, len(insertedConstInstructions))
Expand Down Expand Up @@ -85,7 +84,6 @@ func TestCompiler_lowerBlockArguments(t *testing.T) {
insertMoves = append(insertMoves, struct{ src, dst regalloc.VReg }{src: src, dst: dst})
}}
c := newCompiler(context.Background(), m, builder)
c.ssaValueDefinitions = []SSAValueDefinition{{}, {}, {}, {}}
c.ssaValueToVRegs = []regalloc.VReg{0, 1, 2, 3}
c.nextVRegID = 100 // Temporary reg should start with 100.
return c, []ssa.Value{v2, v1, v3 /* Swaps v1, v2 and pass v3 as-is. */}, blk, func(t *testing.T) {
Expand Down Expand Up @@ -123,7 +121,6 @@ func TestCompiler_lowerBlockArguments(t *testing.T) {
insertMoves = append(insertMoves, struct{ src, dst regalloc.VReg }{src: src, dst: dst})
}}
c := newCompiler(context.Background(), m, builder)
c.ssaValueDefinitions = []SSAValueDefinition{{}, {}}
c.ssaValueToVRegs = []regalloc.VReg{0, 1}
return c, []ssa.Value{add.Return()}, blk, func(t *testing.T) {
require.Equal(t, 1, len(insertMoves))
Expand Down
2 changes: 1 addition & 1 deletion internal/engine/wazevo/backend/isa/amd64/lower_mem.go
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Original file line number Diff line number Diff line change
Expand Up @@ -130,7 +130,7 @@ func (m *machine) lowerAddendsToAmode(x, y addend, offBase uint32) *amode {
}
}

func (m *machine) lowerAddend(x *backend.SSAValueDefinition) addend {
func (m *machine) lowerAddend(x backend.SSAValueDefinition) addend {
if !x.IsFromInstr() {
return addend{m.c.VRegOf(x.V), 0, 0}
}
Expand Down
52 changes: 26 additions & 26 deletions internal/engine/wazevo/backend/isa/amd64/lower_mem_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -34,9 +34,9 @@ func TestMachine_lowerToAddressMode(t *testing.T) {
iadd := b.AllocateInstruction().AsIadd(iconst1.Return(), iconst2.Return()).Insert(b)
ptr = iadd.Return()
offset = 3
ctx.definitions[iconst1.Return()] = &backend.SSAValueDefinition{Instr: iconst1}
ctx.definitions[iconst2.Return()] = &backend.SSAValueDefinition{Instr: iconst2}
ctx.definitions[ptr] = &backend.SSAValueDefinition{Instr: iadd}
ctx.definitions[iconst1.Return()] = backend.SSAValueDefinition{Instr: iconst1}
ctx.definitions[iconst2.Return()] = backend.SSAValueDefinition{Instr: iconst2}
ctx.definitions[ptr] = backend.SSAValueDefinition{Instr: iadd}
return
},
insts: []string{
Expand All @@ -52,10 +52,10 @@ func TestMachine_lowerToAddressMode(t *testing.T) {
iadd := b.AllocateInstruction().AsIadd(iconst1.Return(), p).Insert(b)
ptr = iadd.Return()
offset = 3
ctx.definitions[iconst1.Return()] = &backend.SSAValueDefinition{Instr: iconst1}
ctx.definitions[iconst1.Return()] = backend.SSAValueDefinition{Instr: iconst1}
ctx.vRegMap[p] = raxVReg
ctx.definitions[p] = &backend.SSAValueDefinition{V: p}
ctx.definitions[ptr] = &backend.SSAValueDefinition{Instr: iadd}
ctx.definitions[p] = backend.SSAValueDefinition{V: p}
ctx.definitions[ptr] = backend.SSAValueDefinition{Instr: iadd}
return
},
am: newAmodeImmReg(1+3, raxVReg),
Expand All @@ -69,10 +69,10 @@ func TestMachine_lowerToAddressMode(t *testing.T) {
ptr = iadd.Return()
offset = 3
ctx.vRegMap[p1] = raxVReg
ctx.definitions[p1] = &backend.SSAValueDefinition{V: p1}
ctx.definitions[p1] = backend.SSAValueDefinition{V: p1}
ctx.vRegMap[p2] = rcxVReg
ctx.definitions[p2] = &backend.SSAValueDefinition{V: p2}
ctx.definitions[ptr] = &backend.SSAValueDefinition{Instr: iadd}
ctx.definitions[p2] = backend.SSAValueDefinition{V: p2}
ctx.definitions[ptr] = backend.SSAValueDefinition{Instr: iadd}
return
},
am: newAmodeRegRegShift(3, raxVReg, rcxVReg, 0),
Expand All @@ -83,7 +83,7 @@ func TestMachine_lowerToAddressMode(t *testing.T) {
ptr = b.CurrentBlock().AddParam(b, ssa.TypeI64)
offset = 1 << 31
ctx.vRegMap[ptr] = raxVReg
ctx.definitions[ptr] = &backend.SSAValueDefinition{V: ptr}
ctx.definitions[ptr] = backend.SSAValueDefinition{V: ptr}
return
},
insts: []string{
Expand All @@ -98,8 +98,8 @@ func TestMachine_lowerToAddressMode(t *testing.T) {
in: func(ctx *mockCompiler, b ssa.Builder, m *machine) (ptr ssa.Value, offset uint32) {
iconst32 := b.AllocateInstruction().AsIconst32(123).Insert(b)
uextend := b.AllocateInstruction().AsUExtend(iconst32.Return(), 32, 64).Insert(b)
ctx.definitions[iconst32.Return()] = &backend.SSAValueDefinition{Instr: iconst32}
ctx.definitions[uextend.Return()] = &backend.SSAValueDefinition{Instr: uextend}
ctx.definitions[iconst32.Return()] = backend.SSAValueDefinition{Instr: iconst32}
ctx.definitions[uextend.Return()] = backend.SSAValueDefinition{Instr: uextend}
return uextend.Return(), 0
},
insts: []string{
Expand All @@ -114,9 +114,9 @@ func TestMachine_lowerToAddressMode(t *testing.T) {
iconst64 := b.AllocateInstruction().AsIconst64(2).Insert(b)
ishl := b.AllocateInstruction().AsIshl(p, iconst64.Return()).Insert(b)
ctx.vRegMap[p] = raxVReg
ctx.definitions[p] = &backend.SSAValueDefinition{V: p}
ctx.definitions[iconst64.Return()] = &backend.SSAValueDefinition{Instr: iconst64}
ctx.definitions[ishl.Return()] = &backend.SSAValueDefinition{Instr: ishl}
ctx.definitions[p] = backend.SSAValueDefinition{V: p}
ctx.definitions[iconst64.Return()] = backend.SSAValueDefinition{Instr: iconst64}
ctx.definitions[ishl.Return()] = backend.SSAValueDefinition{Instr: ishl}
return ishl.Return(), 1 << 30
},
insts: []string{
Expand All @@ -133,12 +133,12 @@ func TestMachine_lowerToAddressMode(t *testing.T) {
ishl := b.AllocateInstruction().AsIshl(p1, const2.Return()).Insert(b)
iadd := b.AllocateInstruction().AsIadd(p2, ishl.Return()).Insert(b)
ctx.vRegMap[p1] = raxVReg
ctx.definitions[p1] = &backend.SSAValueDefinition{V: p1}
ctx.definitions[p1] = backend.SSAValueDefinition{V: p1}
ctx.vRegMap[p2] = rcxVReg
ctx.definitions[p2] = &backend.SSAValueDefinition{V: p2}
ctx.definitions[const2.Return()] = &backend.SSAValueDefinition{Instr: const2}
ctx.definitions[ishl.Return()] = &backend.SSAValueDefinition{Instr: ishl}
ctx.definitions[iadd.Return()] = &backend.SSAValueDefinition{Instr: iadd}
ctx.definitions[p2] = backend.SSAValueDefinition{V: p2}
ctx.definitions[const2.Return()] = backend.SSAValueDefinition{Instr: const2}
ctx.definitions[ishl.Return()] = backend.SSAValueDefinition{Instr: ishl}
ctx.definitions[iadd.Return()] = backend.SSAValueDefinition{Instr: iadd}
return iadd.Return(), 1 << 30
},
am: newAmodeRegRegShift(1<<30, rcxVReg, raxVReg, 2),
Expand Down Expand Up @@ -179,7 +179,7 @@ func TestMachine_lowerAddendFromInstr(t *testing.T) {
name: "uextend const32",
in: func(ctx *mockCompiler, b ssa.Builder, m *machine) *ssa.Instruction {
iconst32 := b.AllocateInstruction().AsIconst32(123).Insert(b)
ctx.definitions[iconst32.Return()] = &backend.SSAValueDefinition{Instr: iconst32}
ctx.definitions[iconst32.Return()] = backend.SSAValueDefinition{Instr: iconst32}
return b.AllocateInstruction().AsUExtend(iconst32.Return(), 32, 64).Insert(b)
},
exp: addend{regalloc.VRegInvalid, 123, 0},
Expand All @@ -189,7 +189,7 @@ func TestMachine_lowerAddendFromInstr(t *testing.T) {
in: func(ctx *mockCompiler, b ssa.Builder, m *machine) *ssa.Instruction {
p := b.CurrentBlock().AddParam(b, ssa.TypeI32)
ctx.vRegMap[p] = raxVReg
ctx.definitions[p] = &backend.SSAValueDefinition{V: p}
ctx.definitions[p] = backend.SSAValueDefinition{V: p}
return b.AllocateInstruction().AsUExtend(p, 32, 64).Insert(b)
},
exp: addend{raxVReg, 0, 0},
Expand All @@ -199,7 +199,7 @@ func TestMachine_lowerAddendFromInstr(t *testing.T) {
in: func(ctx *mockCompiler, b ssa.Builder, m *machine) *ssa.Instruction {
p := b.CurrentBlock().AddParam(b, ssa.TypeI32)
ctx.vRegMap[p] = raxVReg
ctx.definitions[p] = &backend.SSAValueDefinition{V: p}
ctx.definitions[p] = backend.SSAValueDefinition{V: p}
return b.AllocateInstruction().AsUExtend(p, 32, 64).Insert(b)
},
exp: addend{raxVReg, 0, 0},
Expand All @@ -208,7 +208,7 @@ func TestMachine_lowerAddendFromInstr(t *testing.T) {
name: "sextend const32",
in: func(ctx *mockCompiler, b ssa.Builder, m *machine) *ssa.Instruction {
iconst32 := b.AllocateInstruction().AsIconst32(123).Insert(b)
ctx.definitions[iconst32.Return()] = &backend.SSAValueDefinition{Instr: iconst32}
ctx.definitions[iconst32.Return()] = backend.SSAValueDefinition{Instr: iconst32}
return b.AllocateInstruction().AsSExtend(iconst32.Return(), 32, 64).Insert(b)
},
exp: addend{regalloc.VRegInvalid, 123, 0},
Expand All @@ -218,7 +218,7 @@ func TestMachine_lowerAddendFromInstr(t *testing.T) {
in: func(ctx *mockCompiler, b ssa.Builder, m *machine) *ssa.Instruction {
p := b.CurrentBlock().AddParam(b, ssa.TypeI32)
ctx.vRegMap[p] = raxVReg
ctx.definitions[p] = &backend.SSAValueDefinition{V: p}
ctx.definitions[p] = backend.SSAValueDefinition{V: p}
return b.AllocateInstruction().AsSExtend(p, 32, 64).Insert(b)
},
exp: addend{raxVReg, 0, 0},
Expand All @@ -228,7 +228,7 @@ func TestMachine_lowerAddendFromInstr(t *testing.T) {
in: func(ctx *mockCompiler, b ssa.Builder, m *machine) *ssa.Instruction {
p := b.CurrentBlock().AddParam(b, ssa.TypeI32)
ctx.vRegMap[p] = raxVReg
ctx.definitions[p] = &backend.SSAValueDefinition{V: p}
ctx.definitions[p] = backend.SSAValueDefinition{V: p}
return b.AllocateInstruction().AsSExtend(p, 32, 64).Insert(b)
},
exp: addend{raxVReg, 0, 0},
Expand Down
15 changes: 9 additions & 6 deletions internal/engine/wazevo/backend/isa/amd64/machine.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1601,21 +1601,24 @@ func (m *machine) lowerExitIfTrueWithCode(execCtx regalloc.VReg, cond ssa.Value,
jmpIf.asJmpIf(condFromSSAIntCmpCond(c).invert(), newOperandLabel(l))
}

func (m *machine) tryLowerBandToFlag(x, y *backend.SSAValueDefinition) (ok bool) {
var target *backend.SSAValueDefinition
func (m *machine) tryLowerBandToFlag(x, y backend.SSAValueDefinition) (ok bool) {
var target backend.SSAValueDefinition
var got bool
if x.IsFromInstr() && x.Instr.Constant() && x.Instr.ConstantVal() == 0 {
if m.c.MatchInstr(y, ssa.OpcodeBand) {
target = y
got = true
}
}

if y.IsFromInstr() && y.Instr.Constant() && y.Instr.ConstantVal() == 0 {
if m.c.MatchInstr(x, ssa.OpcodeBand) {
target = x
got = true
}
}

if target == nil {
if !got {
return false
}

Expand Down Expand Up @@ -1947,9 +1950,9 @@ func (m *machine) lowerCall(si *ssa.Instruction) {

// callerGenVRegToFunctionArg is the opposite of GenFunctionArgToVReg, which is used to generate the
// caller side of the function call.
func (m *machine) callerGenVRegToFunctionArg(a *backend.FunctionABI, argIndex int, reg regalloc.VReg, def *backend.SSAValueDefinition, stackSlotSize int64) {
func (m *machine) callerGenVRegToFunctionArg(a *backend.FunctionABI, argIndex int, reg regalloc.VReg, def backend.SSAValueDefinition, stackSlotSize int64) {
arg := &a.Args[argIndex]
if def != nil && def.IsFromInstr() {
if def.IsFromInstr() {
// Constant instructions are inlined.
if inst := def.Instr; inst.Constant() {
m.insertLoadConstant(inst, reg)
Expand Down Expand Up @@ -2210,7 +2213,7 @@ func (m *machine) ResolveRelocations(refToBinaryOffset []int, binary []byte, rel
// CallTrampolineIslandInfo implements backend.Machine CallTrampolineIslandInfo.
func (m *machine) CallTrampolineIslandInfo(_ int) (_, _ int, _ error) { return }

func (m *machine) lowerIcmpToFlag(xd, yd *backend.SSAValueDefinition, _64 bool) {
func (m *machine) lowerIcmpToFlag(xd, yd backend.SSAValueDefinition, _64 bool) {
x := m.getOperand_Reg(xd)
y := m.getOperand_Mem_Imm32_Reg(yd)
cmp := m.allocateInstr().asCmpRmiR(true, y, x.reg(), _64)
Expand Down
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