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cmd/compile: don't use duffcopy and duffzero on Plan 9

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The ssa compiler uses the duffcopy and duffzero functions,
which rely on the MOVUPS instructions.

However, this doesn't work on Plan 9, since floating point
operations are not allowed in the note handler.

This change disables the use of duffcopy and duffzero
on Plan 9 in the ssa compiler.

Updates #14605.

Change-Id: I017f8ff83de00eabaf7e146b4344a863db1dfddc
Reviewed-on: https://go-review.googlesource.com/20171
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David du Colombier <0intro@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
David du Colombier 2016-03-03 19:45:24 +01:00
parent 466c948b55
commit d55a099e22
3 changed files with 32 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
src/cmd/compile/internal/ssa/config.go
View File

@ -13,16 +13,17 @@ import (
)
type Config struct {
arch string // "amd64", etc.
IntSize int64 // 4 or 8
PtrSize int64 // 4 or 8
lowerBlock func(*Block) bool // lowering function
lowerValue func(*Value, *Config) bool // lowering function
fe Frontend // callbacks into compiler frontend
HTML *HTMLWriter // html writer, for debugging
ctxt *obj.Link // Generic arch information
optimize bool // Do optimization
curFunc *Func
arch string // "amd64", etc.
IntSize int64 // 4 or 8
PtrSize int64 // 4 or 8
lowerBlock func(*Block) bool // lowering function
lowerValue func(*Value, *Config) bool // lowering function
fe Frontend // callbacks into compiler frontend
HTML *HTMLWriter // html writer, for debugging
ctxt *obj.Link // Generic arch information
optimize bool // Do optimization
noDuffDevice bool // Don't use Duff's device
curFunc *Func
// TODO: more stuff. Compiler flags of interest, ...
@ -122,6 +123,12 @@ func NewConfig(arch string, fe Frontend, ctxt *obj.Link, optimize bool) *Config
c.ctxt = ctxt
c.optimize = optimize
// Don't use Duff's device on Plan 9, because floating
// point operations are not allowed in note handler.
if obj.Getgoos() == "plan9" {
c.noDuffDevice = true
}
// Assign IDs to preallocated values/blocks.
for i := range c.values {
c.values[i].ID = ID(i)

10
src/cmd/compile/internal/ssa/gen/AMD64.rules
View File

@ -328,7 +328,7 @@
(MOVOstore dst (MOVOload src mem) mem))
// Medium copying uses a duff device.
(Move [size] dst src mem) && size >= 32 && size <= 16*64 && size%16 == 0 ->
(Move [size] dst src mem) && size >= 32 && size <= 16*64 && size%16 == 0 && !config.noDuffDevice ->
(DUFFCOPY [14*(64-size/16)] dst src mem)
// 14 and 64 are magic constants. 14 is the number of bytes to encode:
// MOVUPS (SI), X0
@ -338,7 +338,7 @@
// and 64 is the number of such blocks. See src/runtime/duff_amd64.s:duffcopy.
// Large copying uses REP MOVSQ.
(Move [size] dst src mem) && size > 16*64 && size%8 == 0 ->
(Move [size] dst src mem) && (size > 16*64 || config.noDuffDevice) && size%8 == 0 ->
(REPMOVSQ dst src (MOVQconst [size/8]) mem)
(Not x) -> (XORBconst [1] x)
@ -869,13 +869,13 @@
(MOVQstoreconst [0] destptr mem))))
// Medium zeroing uses a duff device.
(Zero [size] destptr mem) && size <= 1024 && size%8 == 0 && size%16 != 0 ->
(Zero [size] destptr mem) && size <= 1024 && size%8 == 0 && size%16 != 0 && !config.noDuffDevice ->
(Zero [size-8] (ADDQconst [8] destptr) (MOVQstore destptr (MOVQconst [0]) mem))
(Zero [size] destptr mem) && size <= 1024 && size%16 == 0 ->
(Zero [size] destptr mem) && size <= 1024 && size%16 == 0 && !config.noDuffDevice ->
(DUFFZERO [duffStart(size)] (ADDQconst [duffAdj(size)] destptr) (MOVOconst [0]) mem)
// Large zeroing uses REP STOSQ.
(Zero [size] destptr mem) && size > 1024 && size%8 == 0 ->
(Zero [size] destptr mem) && (size > 1024 || (config.noDuffDevice && size > 32)) && size%8 == 0 ->
(REPSTOSQ destptr (MOVQconst [size/8]) (MOVQconst [0]) mem)
// Absorb InvertFlags into branches.

20
src/cmd/compile/internal/ssa/rewriteAMD64.go
View File

@ -8811,14 +8811,14 @@ func rewriteValueAMD64_OpMove(v *Value, config *Config) bool {
return true
}
// match: (Move [size] dst src mem)
// cond: size >= 32 && size <= 16*64 && size%16 == 0
// cond: size >= 32 && size <= 16*64 && size%16 == 0 && !config.noDuffDevice
// result: (DUFFCOPY [14*(64-size/16)] dst src mem)
for {
size := v.AuxInt
dst := v.Args[0]
src := v.Args[1]
mem := v.Args[2]
if !(size >= 32 && size <= 16*64 && size%16 == 0) {
if !(size >= 32 && size <= 16*64 && size%16 == 0 && !config.noDuffDevice) {
break
}
v.reset(OpAMD64DUFFCOPY)
@ -8829,14 +8829,14 @@ func rewriteValueAMD64_OpMove(v *Value, config *Config) bool {
return true
}
// match: (Move [size] dst src mem)
// cond: size > 16*64 && size%8 == 0
// cond: (size > 16*64 || config.noDuffDevice) && size%8 == 0
// result: (REPMOVSQ dst src (MOVQconst [size/8]) mem)
for {
size := v.AuxInt
dst := v.Args[0]
src := v.Args[1]
mem := v.Args[2]
if !(size > 16*64 && size%8 == 0) {
if !((size > 16*64 || config.noDuffDevice) && size%8 == 0) {
break
}
v.reset(OpAMD64REPMOVSQ)
@ -13693,13 +13693,13 @@ func rewriteValueAMD64_OpZero(v *Value, config *Config) bool {
return true
}
// match: (Zero [size] destptr mem)
// cond: size <= 1024 && size%8 == 0 && size%16 != 0
// cond: size <= 1024 && size%8 == 0 && size%16 != 0 && !config.noDuffDevice
// result: (Zero [size-8] (ADDQconst [8] destptr) (MOVQstore destptr (MOVQconst [0]) mem))
for {
size := v.AuxInt
destptr := v.Args[0]
mem := v.Args[1]
if !(size <= 1024 && size%8 == 0 && size%16 != 0) {
if !(size <= 1024 && size%8 == 0 && size%16 != 0 && !config.noDuffDevice) {
break
}
v.reset(OpZero)
@ -13718,13 +13718,13 @@ func rewriteValueAMD64_OpZero(v *Value, config *Config) bool {
return true
}
// match: (Zero [size] destptr mem)
// cond: size <= 1024 && size%16 == 0
// cond: size <= 1024 && size%16 == 0 && !config.noDuffDevice
// result: (DUFFZERO [duffStart(size)] (ADDQconst [duffAdj(size)] destptr) (MOVOconst [0]) mem)
for {
size := v.AuxInt
destptr := v.Args[0]
mem := v.Args[1]
if !(size <= 1024 && size%16 == 0) {
if !(size <= 1024 && size%16 == 0 && !config.noDuffDevice) {
break
}
v.reset(OpAMD64DUFFZERO)
@ -13740,13 +13740,13 @@ func rewriteValueAMD64_OpZero(v *Value, config *Config) bool {
return true
}
// match: (Zero [size] destptr mem)
// cond: size > 1024 && size%8 == 0
// cond: (size > 1024 || (config.noDuffDevice && size > 32)) && size%8 == 0
// result: (REPSTOSQ destptr (MOVQconst [size/8]) (MOVQconst [0]) mem)
for {
size := v.AuxInt
destptr := v.Args[0]
mem := v.Args[1]
if !(size > 1024 && size%8 == 0) {
if !((size > 1024 || (config.noDuffDevice && size > 32)) && size%8 == 0) {
break
}
v.reset(OpAMD64REPSTOSQ)