cmd/compile: add SSA config options useAvg and useHmul

This commit allows architectures to disable optimizations that need the
Avg* and Hmul* operations.

WebAssembly has no such operations, so using them as an optimization
but then having to emulate them with multiple instructions makes no
sense, especially since the WebAssembly compiler may do the same
optimizations internally.

Updates #18892

Change-Id: If57b59e3235482a9e0ec334a7312b3e3b5fc2b61
Reviewed-on: https://go-review.googlesource.com/103256
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

diff --git a/src/cmd/compile/internal/ssa/config.go b/src/cmd/compile/internal/ssa/config.go
index ad8416e9e17f17cd39cb81349f17bb8625725c54..6ae1c5a87076b1b7de7863239a65d8517a8cf0fa 100644 (file)
--- a/src/cmd/compile/internal/ssa/config.go
+++ b/src/cmd/compile/internal/ssa/config.go
@@ -34,6 +34,8 @@ type Config struct {
        optimize        bool          // Do optimization
        noDuffDevice    bool          // Don't use Duff's device
        useSSE          bool          // Use SSE for non-float operations
+       useAvg          bool          // Use optimizations that need Avg* operations
+       useHmul         bool          // Use optimizations that need Hmul* operations
        nacl            bool          // GOOS=nacl
        use387          bool          // GO386=387
        SoftFloat       bool          //
@@ -190,6 +192,8 @@ const (
 // NewConfig returns a new configuration object for the given architecture.
 func NewConfig(arch string, types Types, ctxt *obj.Link, optimize bool) *Config {
        c := &Config{arch: arch, Types: types}
+       c.useAvg = true
+       c.useHmul = true
        switch arch {
        case "amd64":
                c.PtrSize = 8

diff --git a/src/cmd/compile/internal/ssa/gen/generic.rules b/src/cmd/compile/internal/ssa/gen/generic.rules
index e6797103d517f056f3bc728f249c54b45dfda07a..24fb52c8925b39aed8600de4a68911f5d835f4fa 100644 (file)
--- a/src/cmd/compile/internal/ssa/gen/generic.rules
+++ b/src/cmd/compile/internal/ssa/gen/generic.rules
@@ -845,7 +845,7 @@
         (Const32 <typ.UInt32> [int64(1<<15+(umagic(16,c).m+1)/2)])
         (Rsh32Ux64 <typ.UInt32> (ZeroExt16to32 x) (Const64 <typ.UInt64> [1])))
       (Const64 <typ.UInt64> [16+umagic(16,c).s-2])))
-(Div16u x (Const16 [c])) && umagicOK(16, c) && config.RegSize == 4 ->
+(Div16u x (Const16 [c])) && umagicOK(16, c) && config.RegSize == 4 && config.useAvg ->
   (Trunc32to16
     (Rsh32Ux64 <typ.UInt32>
       (Avg32u
@@ -856,19 +856,19 @@
       (Const64 <typ.UInt64> [16+umagic(16,c).s-1])))
 
 // For 32-bit divides on 32-bit machines
-(Div32u x (Const32 [c])) && umagicOK(32, c) && config.RegSize == 4 && umagic(32,c).m&1 == 0 ->
+(Div32u x (Const32 [c])) && umagicOK(32, c) && config.RegSize == 4 && umagic(32,c).m&1 == 0 && config.useHmul ->
   (Rsh32Ux64 <typ.UInt32>
     (Hmul32u <typ.UInt32>
       (Const32 <typ.UInt32> [int64(int32(1<<31+umagic(32,c).m/2))])
       x)
     (Const64 <typ.UInt64> [umagic(32,c).s-1]))
-(Div32u x (Const32 [c])) && umagicOK(32, c) && config.RegSize == 4 && c&1 == 0 ->
+(Div32u x (Const32 [c])) && umagicOK(32, c) && config.RegSize == 4 && c&1 == 0 && config.useHmul ->
   (Rsh32Ux64 <typ.UInt32>
     (Hmul32u <typ.UInt32>
       (Const32 <typ.UInt32> [int64(int32(1<<31+(umagic(32,c).m+1)/2))])
       (Rsh32Ux64 <typ.UInt32> x (Const64 <typ.UInt64> [1])))
     (Const64 <typ.UInt64> [umagic(32,c).s-2]))
-(Div32u x (Const32 [c])) && umagicOK(32, c) && config.RegSize == 4 ->
+(Div32u x (Const32 [c])) && umagicOK(32, c) && config.RegSize == 4 && config.useAvg && config.useHmul ->
   (Rsh32Ux64 <typ.UInt32>
     (Avg32u
       x
@@ -893,7 +893,7 @@
         (Const64 <typ.UInt64> [int64(1<<31+(umagic(32,c).m+1)/2)])
         (Rsh64Ux64 <typ.UInt64> (ZeroExt32to64 x) (Const64 <typ.UInt64> [1])))
       (Const64 <typ.UInt64> [32+umagic(32,c).s-2])))
-(Div32u x (Const32 [c])) && umagicOK(32, c) && config.RegSize == 8 ->
+(Div32u x (Const32 [c])) && umagicOK(32, c) && config.RegSize == 8 && config.useAvg ->
   (Trunc64to32
     (Rsh64Ux64 <typ.UInt64>
       (Avg64u
@@ -905,19 +905,19 @@
 
 // For 64-bit divides on 64-bit machines
 // (64-bit divides on 32-bit machines are lowered to a runtime call by the walk pass.)
-(Div64u x (Const64 [c])) && umagicOK(64, c) && config.RegSize == 8 && umagic(64,c).m&1 == 0 ->
+(Div64u x (Const64 [c])) && umagicOK(64, c) && config.RegSize == 8 && umagic(64,c).m&1 == 0 && config.useHmul ->
   (Rsh64Ux64 <typ.UInt64>
     (Hmul64u <typ.UInt64>
       (Const64 <typ.UInt64> [int64(1<<63+umagic(64,c).m/2)])
       x)
     (Const64 <typ.UInt64> [umagic(64,c).s-1]))
-(Div64u x (Const64 [c])) && umagicOK(64, c) && config.RegSize == 8 && c&1 == 0 ->
+(Div64u x (Const64 [c])) && umagicOK(64, c) && config.RegSize == 8 && c&1 == 0 && config.useHmul ->
   (Rsh64Ux64 <typ.UInt64>
     (Hmul64u <typ.UInt64>
       (Const64 <typ.UInt64> [int64(1<<63+(umagic(64,c).m+1)/2)])
       (Rsh64Ux64 <typ.UInt64> x (Const64 <typ.UInt64> [1])))
     (Const64 <typ.UInt64> [umagic(64,c).s-2]))
-(Div64u x (Const64 [c])) && umagicOK(64, c) && config.RegSize == 8 ->
+(Div64u x (Const64 [c])) && umagicOK(64, c) && config.RegSize == 8 && config.useAvg && config.useHmul ->
   (Rsh64Ux64 <typ.UInt64>
     (Avg64u
       x
@@ -992,7 +992,7 @@
     (Rsh64x64 <t>
       (SignExt32to64 x)
       (Const64 <typ.UInt64> [63])))
-(Div32 <t> x (Const32 [c])) && smagicOK(32,c) && config.RegSize == 4 && smagic(32,c).m&1 == 0 ->
+(Div32 <t> x (Const32 [c])) && smagicOK(32,c) && config.RegSize == 4 && smagic(32,c).m&1 == 0 && config.useHmul ->
   (Sub32 <t>
     (Rsh32x64 <t>
       (Hmul32 <t>
@@ -1002,7 +1002,7 @@
     (Rsh32x64 <t>
       x
       (Const64 <typ.UInt64> [31])))
-(Div32 <t> x (Const32 [c])) && smagicOK(32,c) && config.RegSize == 4 && smagic(32,c).m&1 != 0 ->
+(Div32 <t> x (Const32 [c])) && smagicOK(32,c) && config.RegSize == 4 && smagic(32,c).m&1 != 0 && config.useHmul ->
   (Sub32 <t>
     (Rsh32x64 <t>
       (Add32 <t>
@@ -1014,7 +1014,7 @@
     (Rsh32x64 <t>
       x
       (Const64 <typ.UInt64> [31])))
-(Div64 <t> x (Const64 [c])) && smagicOK(64,c) && smagic(64,c).m&1 == 0 ->
+(Div64 <t> x (Const64 [c])) && smagicOK(64,c) && smagic(64,c).m&1 == 0 && config.useHmul ->
   (Sub64 <t>
     (Rsh64x64 <t>
       (Hmul64 <t>
@@ -1024,7 +1024,7 @@
     (Rsh64x64 <t>
       x
       (Const64 <typ.UInt64> [63])))
-(Div64 <t> x (Const64 [c])) && smagicOK(64,c) && smagic(64,c).m&1 != 0 ->
+(Div64 <t> x (Const64 [c])) && smagicOK(64,c) && smagic(64,c).m&1 != 0 && config.useHmul ->
   (Sub64 <t>
     (Rsh64x64 <t>
       (Add64 <t>

diff --git a/src/cmd/compile/internal/ssa/rewritegeneric.go b/src/cmd/compile/internal/ssa/rewritegeneric.go
index 414514c5ac1d0d25d28a552f1f04b12b51daf379..542c669848b4910a590bb9b8f2f5273bd6f6738f 100644 (file)
--- a/src/cmd/compile/internal/ssa/rewritegeneric.go
+++ b/src/cmd/compile/internal/ssa/rewritegeneric.go
@@ -7990,7 +7990,7 @@ func rewriteValuegeneric_OpDiv16u_0(v *Value) bool {
                return true
        }
        // match: (Div16u x (Const16 [c]))
-       // cond: umagicOK(16, c) && config.RegSize == 4
+       // cond: umagicOK(16, c) && config.RegSize == 4 && config.useAvg
        // result: (Trunc32to16 (Rsh32Ux64 <typ.UInt32> (Avg32u (Lsh32x64 <typ.UInt32> (ZeroExt16to32 x) (Const64 <typ.UInt64> [16])) (Mul32 <typ.UInt32> (Const32 <typ.UInt32> [int64(umagic(16,c).m)]) (ZeroExt16to32 x))) (Const64 <typ.UInt64> [16+umagic(16,c).s-1])))
        for {
                _ = v.Args[1]
@@ -8000,7 +8000,7 @@ func rewriteValuegeneric_OpDiv16u_0(v *Value) bool {
                        break
                }
                c := v_1.AuxInt
-               if !(umagicOK(16, c) && config.RegSize == 4) {
+               if !(umagicOK(16, c) && config.RegSize == 4 && config.useAvg) {
                        break
                }
                v.reset(OpTrunc32to16)
@@ -8207,7 +8207,7 @@ func rewriteValuegeneric_OpDiv32_0(v *Value) bool {
                return true
        }
        // match: (Div32 <t> x (Const32 [c]))
-       // cond: smagicOK(32,c) && config.RegSize == 4 && smagic(32,c).m&1 == 0
+       // cond: smagicOK(32,c) && config.RegSize == 4 && smagic(32,c).m&1 == 0 && config.useHmul
        // result: (Sub32 <t> (Rsh32x64 <t> (Hmul32 <t> (Const32 <typ.UInt32> [int64(int32(smagic(32,c).m/2))]) x) (Const64 <typ.UInt64> [smagic(32,c).s-1])) (Rsh32x64 <t> x (Const64 <typ.UInt64> [31])))
        for {
                t := v.Type
@@ -8218,7 +8218,7 @@ func rewriteValuegeneric_OpDiv32_0(v *Value) bool {
                        break
                }
                c := v_1.AuxInt
-               if !(smagicOK(32, c) && config.RegSize == 4 && smagic(32, c).m&1 == 0) {
+               if !(smagicOK(32, c) && config.RegSize == 4 && smagic(32, c).m&1 == 0 && config.useHmul) {
                        break
                }
                v.reset(OpSub32)
@@ -8243,7 +8243,7 @@ func rewriteValuegeneric_OpDiv32_0(v *Value) bool {
                return true
        }
        // match: (Div32 <t> x (Const32 [c]))
-       // cond: smagicOK(32,c) && config.RegSize == 4 && smagic(32,c).m&1 != 0
+       // cond: smagicOK(32,c) && config.RegSize == 4 && smagic(32,c).m&1 != 0 && config.useHmul
        // result: (Sub32 <t> (Rsh32x64 <t> (Add32 <t> (Hmul32 <t> (Const32 <typ.UInt32> [int64(int32(smagic(32,c).m))]) x) x) (Const64 <typ.UInt64> [smagic(32,c).s])) (Rsh32x64 <t> x (Const64 <typ.UInt64> [31])))
        for {
                t := v.Type
@@ -8254,7 +8254,7 @@ func rewriteValuegeneric_OpDiv32_0(v *Value) bool {
                        break
                }
                c := v_1.AuxInt
-               if !(smagicOK(32, c) && config.RegSize == 4 && smagic(32, c).m&1 != 0) {
+               if !(smagicOK(32, c) && config.RegSize == 4 && smagic(32, c).m&1 != 0 && config.useHmul) {
                        break
                }
                v.reset(OpSub32)
@@ -8380,7 +8380,7 @@ func rewriteValuegeneric_OpDiv32u_0(v *Value) bool {
                return true
        }
        // match: (Div32u x (Const32 [c]))
-       // cond: umagicOK(32, c) && config.RegSize == 4 && umagic(32,c).m&1 == 0
+       // cond: umagicOK(32, c) && config.RegSize == 4 && umagic(32,c).m&1 == 0 && config.useHmul
        // result: (Rsh32Ux64 <typ.UInt32> (Hmul32u <typ.UInt32> (Const32 <typ.UInt32> [int64(int32(1<<31+umagic(32,c).m/2))]) x) (Const64 <typ.UInt64> [umagic(32,c).s-1]))
        for {
                _ = v.Args[1]
@@ -8390,7 +8390,7 @@ func rewriteValuegeneric_OpDiv32u_0(v *Value) bool {
                        break
                }
                c := v_1.AuxInt
-               if !(umagicOK(32, c) && config.RegSize == 4 && umagic(32, c).m&1 == 0) {
+               if !(umagicOK(32, c) && config.RegSize == 4 && umagic(32, c).m&1 == 0 && config.useHmul) {
                        break
                }
                v.reset(OpRsh32Ux64)
@@ -8407,7 +8407,7 @@ func rewriteValuegeneric_OpDiv32u_0(v *Value) bool {
                return true
        }
        // match: (Div32u x (Const32 [c]))
-       // cond: umagicOK(32, c) && config.RegSize == 4 && c&1 == 0
+       // cond: umagicOK(32, c) && config.RegSize == 4 && c&1 == 0 && config.useHmul
        // result: (Rsh32Ux64 <typ.UInt32> (Hmul32u <typ.UInt32> (Const32 <typ.UInt32> [int64(int32(1<<31+(umagic(32,c).m+1)/2))]) (Rsh32Ux64 <typ.UInt32> x (Const64 <typ.UInt64> [1]))) (Const64 <typ.UInt64> [umagic(32,c).s-2]))
        for {
                _ = v.Args[1]
@@ -8417,7 +8417,7 @@ func rewriteValuegeneric_OpDiv32u_0(v *Value) bool {
                        break
                }
                c := v_1.AuxInt
-               if !(umagicOK(32, c) && config.RegSize == 4 && c&1 == 0) {
+               if !(umagicOK(32, c) && config.RegSize == 4 && c&1 == 0 && config.useHmul) {
                        break
                }
                v.reset(OpRsh32Ux64)
@@ -8439,7 +8439,7 @@ func rewriteValuegeneric_OpDiv32u_0(v *Value) bool {
                return true
        }
        // match: (Div32u x (Const32 [c]))
-       // cond: umagicOK(32, c) && config.RegSize == 4
+       // cond: umagicOK(32, c) && config.RegSize == 4 && config.useAvg && config.useHmul
        // result: (Rsh32Ux64 <typ.UInt32> (Avg32u x (Hmul32u <typ.UInt32> (Const32 <typ.UInt32> [int64(int32(umagic(32,c).m))]) x)) (Const64 <typ.UInt64> [umagic(32,c).s-1]))
        for {
                _ = v.Args[1]
@@ -8449,7 +8449,7 @@ func rewriteValuegeneric_OpDiv32u_0(v *Value) bool {
                        break
                }
                c := v_1.AuxInt
-               if !(umagicOK(32, c) && config.RegSize == 4) {
+               if !(umagicOK(32, c) && config.RegSize == 4 && config.useAvg && config.useHmul) {
                        break
                }
                v.reset(OpRsh32Ux64)
@@ -8534,7 +8534,7 @@ func rewriteValuegeneric_OpDiv32u_0(v *Value) bool {
                return true
        }
        // match: (Div32u x (Const32 [c]))
-       // cond: umagicOK(32, c) && config.RegSize == 8
+       // cond: umagicOK(32, c) && config.RegSize == 8 && config.useAvg
        // result: (Trunc64to32 (Rsh64Ux64 <typ.UInt64> (Avg64u (Lsh64x64 <typ.UInt64> (ZeroExt32to64 x) (Const64 <typ.UInt64> [32])) (Mul64 <typ.UInt64> (Const64 <typ.UInt32> [int64(umagic(32,c).m)]) (ZeroExt32to64 x))) (Const64 <typ.UInt64> [32+umagic(32,c).s-1])))
        for {
                _ = v.Args[1]
@@ -8544,7 +8544,7 @@ func rewriteValuegeneric_OpDiv32u_0(v *Value) bool {
                        break
                }
                c := v_1.AuxInt
-               if !(umagicOK(32, c) && config.RegSize == 8) {
+               if !(umagicOK(32, c) && config.RegSize == 8 && config.useAvg) {
                        break
                }
                v.reset(OpTrunc64to32)
@@ -8578,6 +8578,8 @@ func rewriteValuegeneric_OpDiv32u_0(v *Value) bool {
 func rewriteValuegeneric_OpDiv64_0(v *Value) bool {
        b := v.Block
        _ = b
+       config := b.Func.Config
+       _ = config
        typ := &b.Func.Config.Types
        _ = typ
        // match: (Div64 (Const64 [c]) (Const64 [d]))
@@ -8729,7 +8731,7 @@ func rewriteValuegeneric_OpDiv64_0(v *Value) bool {
                return true
        }
        // match: (Div64 <t> x (Const64 [c]))
-       // cond: smagicOK(64,c) && smagic(64,c).m&1 == 0
+       // cond: smagicOK(64,c) && smagic(64,c).m&1 == 0 && config.useHmul
        // result: (Sub64 <t> (Rsh64x64 <t> (Hmul64 <t> (Const64 <typ.UInt64> [int64(smagic(64,c).m/2)]) x) (Const64 <typ.UInt64> [smagic(64,c).s-1])) (Rsh64x64 <t> x (Const64 <typ.UInt64> [63])))
        for {
                t := v.Type
@@ -8740,7 +8742,7 @@ func rewriteValuegeneric_OpDiv64_0(v *Value) bool {
                        break
                }
                c := v_1.AuxInt
-               if !(smagicOK(64, c) && smagic(64, c).m&1 == 0) {
+               if !(smagicOK(64, c) && smagic(64, c).m&1 == 0 && config.useHmul) {
                        break
                }
                v.reset(OpSub64)
@@ -8765,7 +8767,7 @@ func rewriteValuegeneric_OpDiv64_0(v *Value) bool {
                return true
        }
        // match: (Div64 <t> x (Const64 [c]))
-       // cond: smagicOK(64,c) && smagic(64,c).m&1 != 0
+       // cond: smagicOK(64,c) && smagic(64,c).m&1 != 0 && config.useHmul
        // result: (Sub64 <t> (Rsh64x64 <t> (Add64 <t> (Hmul64 <t> (Const64 <typ.UInt64> [int64(smagic(64,c).m)]) x) x) (Const64 <typ.UInt64> [smagic(64,c).s])) (Rsh64x64 <t> x (Const64 <typ.UInt64> [63])))
        for {
                t := v.Type
@@ -8776,7 +8778,7 @@ func rewriteValuegeneric_OpDiv64_0(v *Value) bool {
                        break
                }
                c := v_1.AuxInt
-               if !(smagicOK(64, c) && smagic(64, c).m&1 != 0) {
+               if !(smagicOK(64, c) && smagic(64, c).m&1 != 0 && config.useHmul) {
                        break
                }
                v.reset(OpSub64)
@@ -8922,7 +8924,7 @@ func rewriteValuegeneric_OpDiv64u_0(v *Value) bool {
                return true
        }
        // match: (Div64u x (Const64 [c]))
-       // cond: umagicOK(64, c) && config.RegSize == 8 && umagic(64,c).m&1 == 0
+       // cond: umagicOK(64, c) && config.RegSize == 8 && umagic(64,c).m&1 == 0 && config.useHmul
        // result: (Rsh64Ux64 <typ.UInt64> (Hmul64u <typ.UInt64> (Const64 <typ.UInt64> [int64(1<<63+umagic(64,c).m/2)]) x) (Const64 <typ.UInt64> [umagic(64,c).s-1]))
        for {
                _ = v.Args[1]
@@ -8932,7 +8934,7 @@ func rewriteValuegeneric_OpDiv64u_0(v *Value) bool {
                        break
                }
                c := v_1.AuxInt
-               if !(umagicOK(64, c) && config.RegSize == 8 && umagic(64, c).m&1 == 0) {
+               if !(umagicOK(64, c) && config.RegSize == 8 && umagic(64, c).m&1 == 0 && config.useHmul) {
                        break
                }
                v.reset(OpRsh64Ux64)
@@ -8949,7 +8951,7 @@ func rewriteValuegeneric_OpDiv64u_0(v *Value) bool {
                return true
        }
        // match: (Div64u x (Const64 [c]))
-       // cond: umagicOK(64, c) && config.RegSize == 8 && c&1 == 0
+       // cond: umagicOK(64, c) && config.RegSize == 8 && c&1 == 0 && config.useHmul
        // result: (Rsh64Ux64 <typ.UInt64> (Hmul64u <typ.UInt64> (Const64 <typ.UInt64> [int64(1<<63+(umagic(64,c).m+1)/2)]) (Rsh64Ux64 <typ.UInt64> x (Const64 <typ.UInt64> [1]))) (Const64 <typ.UInt64> [umagic(64,c).s-2]))
        for {
                _ = v.Args[1]
@@ -8959,7 +8961,7 @@ func rewriteValuegeneric_OpDiv64u_0(v *Value) bool {
                        break
                }
                c := v_1.AuxInt
-               if !(umagicOK(64, c) && config.RegSize == 8 && c&1 == 0) {
+               if !(umagicOK(64, c) && config.RegSize == 8 && c&1 == 0 && config.useHmul) {
                        break
                }
                v.reset(OpRsh64Ux64)
@@ -8981,7 +8983,7 @@ func rewriteValuegeneric_OpDiv64u_0(v *Value) bool {
                return true
        }
        // match: (Div64u x (Const64 [c]))
-       // cond: umagicOK(64, c) && config.RegSize == 8
+       // cond: umagicOK(64, c) && config.RegSize == 8 && config.useAvg && config.useHmul
        // result: (Rsh64Ux64 <typ.UInt64> (Avg64u x (Hmul64u <typ.UInt64> (Const64 <typ.UInt64> [int64(umagic(64,c).m)]) x)) (Const64 <typ.UInt64> [umagic(64,c).s-1]))
        for {
                _ = v.Args[1]
@@ -8991,7 +8993,7 @@ func rewriteValuegeneric_OpDiv64u_0(v *Value) bool {
                        break
                }
                c := v_1.AuxInt
-               if !(umagicOK(64, c) && config.RegSize == 8) {
+               if !(umagicOK(64, c) && config.RegSize == 8 && config.useAvg && config.useHmul) {
                        break
                }
                v.reset(OpRsh64Ux64)