cmd/compile: optimize rule (x + x) << c to x << c+1 on loong64

Change-Id: I782f93510bba92ba60b298c1c1cde456c8bcec38
Reviewed-on: https://go-review.googlesource.com/c/go/+/697956
Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@golang.org>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>

diff --git a/src/cmd/compile/internal/ssa/_gen/LOONG64.rules b/src/cmd/compile/internal/ssa/_gen/LOONG64.rules
index efeeca652c81c79ee9ad87034b8ca44164176415..75b5e3806b0bab47b9cdbfe8be98b3eefbdb083e 100644 (file)
--- a/src/cmd/compile/internal/ssa/_gen/LOONG64.rules
+++ b/src/cmd/compile/internal/ssa/_gen/LOONG64.rules
@@ -749,6 +749,9 @@
 (SRLVconst [rc] (MOVHUreg x)) && rc >= 16 => (MOVVconst [0])
 (SRLVconst [rc] (MOVBUreg x)) && rc >= 8 => (MOVVconst [0])
 
+// (x + x) << c -> x << c+1
+((SLLV|SLL)const [c] (ADDV x x)) => ((SLLV|SLL)const [c+1] x)
+
 // mul by constant
 (MULV _ (MOVVconst [0])) => (MOVVconst [0])
 (MULV x (MOVVconst [1])) => x

diff --git a/src/cmd/compile/internal/ssa/rewriteLOONG64.go b/src/cmd/compile/internal/ssa/rewriteLOONG64.go
index 6f29588f9a51a30209e73cb77e5ccfbd0615d0c2..df4ac818ddafb229f1bc9848075cf61d171b18a8 100644 (file)
--- a/src/cmd/compile/internal/ssa/rewriteLOONG64.go
+++ b/src/cmd/compile/internal/ssa/rewriteLOONG64.go
@@ -468,6 +468,8 @@ func rewriteValueLOONG64(v *Value) bool {
                return rewriteValueLOONG64_OpLOONG64SLLV(v)
        case OpLOONG64SLLVconst:
                return rewriteValueLOONG64_OpLOONG64SLLVconst(v)
+       case OpLOONG64SLLconst:
+               return rewriteValueLOONG64_OpLOONG64SLLconst(v)
        case OpLOONG64SRA:
                return rewriteValueLOONG64_OpLOONG64SRA(v)
        case OpLOONG64SRAV:
@@ -6457,6 +6459,22 @@ func rewriteValueLOONG64_OpLOONG64SLLV(v *Value) bool {
 }
 func rewriteValueLOONG64_OpLOONG64SLLVconst(v *Value) bool {
        v_0 := v.Args[0]
+       // match: (SLLVconst [c] (ADDV x x))
+       // result: (SLLVconst [c+1] x)
+       for {
+               c := auxIntToInt64(v.AuxInt)
+               if v_0.Op != OpLOONG64ADDV {
+                       break
+               }
+               x := v_0.Args[1]
+               if x != v_0.Args[0] {
+                       break
+               }
+               v.reset(OpLOONG64SLLVconst)
+               v.AuxInt = int64ToAuxInt(c + 1)
+               v.AddArg(x)
+               return true
+       }
        // match: (SLLVconst [c] (MOVVconst [d]))
        // result: (MOVVconst [d<<uint64(c)])
        for {
@@ -6471,6 +6489,26 @@ func rewriteValueLOONG64_OpLOONG64SLLVconst(v *Value) bool {
        }
        return false
 }
+func rewriteValueLOONG64_OpLOONG64SLLconst(v *Value) bool {
+       v_0 := v.Args[0]
+       // match: (SLLconst [c] (ADDV x x))
+       // result: (SLLconst [c+1] x)
+       for {
+               c := auxIntToInt64(v.AuxInt)
+               if v_0.Op != OpLOONG64ADDV {
+                       break
+               }
+               x := v_0.Args[1]
+               if x != v_0.Args[0] {
+                       break
+               }
+               v.reset(OpLOONG64SLLconst)
+               v.AuxInt = int64ToAuxInt(c + 1)
+               v.AddArg(x)
+               return true
+       }
+       return false
+}
 func rewriteValueLOONG64_OpLOONG64SRA(v *Value) bool {
        v_1 := v.Args[1]
        v_0 := v.Args[0]

diff --git a/test/codegen/shift.go b/test/codegen/shift.go
index 0e4cf1ed8d681fc08051de8d0ab8cc7241a5fc8e..3ab0fcfabc9e99ff17dd4c3f84da020844c36de3 100644 (file)
--- a/test/codegen/shift.go
+++ b/test/codegen/shift.go
@@ -121,21 +121,25 @@ func rshConst64x32(v int64) int64 {
 
 func lshConst32x1Add(x int32) int32 {
        // amd64:"SHLL\t[$]2"
+       // loong64:"SLL\t[$]2"
        return (x + x) << 1
 }
 
 func lshConst64x1Add(x int64) int64 {
        // amd64:"SHLQ\t[$]2"
+       // loong64:"SLLV\t[$]2"
        return (x + x) << 1
 }
 
 func lshConst32x2Add(x int32) int32 {
        // amd64:"SHLL\t[$]3"
+       // loong64:"SLL\t[$]3"
        return (x + x) << 2
 }
 
 func lshConst64x2Add(x int64) int64 {
        // amd64:"SHLQ\t[$]3"
+       // loong64:"SLLV\t[$]3"
        return (x + x) << 2
 }