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| author | Keith Randall <khr@golang.org> | 2024-06-12 18:25:55 -0700 |
|---|---|---|
| committer | Keith Randall <khr@golang.org> | 2024-07-23 20:53:57 +0000 |
| commit | f66db499769002f1f804f52234b7c3e5917bbad6 (patch) | |
| tree | f4a51d385077e00ee64d98f1561e69ee7ee290d7 /src/cmd | |
| parent | d15525d596eb49eba058178e3b633b5a2ebb4766 (diff) | |
| download | go-f66db499769002f1f804f52234b7c3e5917bbad6.tar.xz | |
cmd/compile: store constant floats using integer constants
x86 is better at storing constant ints than constant floats.
(It uses a constant directly in the instruction stream, instead of
loading it from a constant global memory.)
Noticed as part of #67957
Change-Id: I9b7b586ad8e0fe9ce245324f020e9526f82b209d
Reviewed-on: https://go-review.googlesource.com/c/go/+/592596
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Diffstat (limited to 'src/cmd')
| -rw-r--r-- | src/cmd/compile/internal/ssa/_gen/AMD64.rules | 3 | ||||
| -rw-r--r-- | src/cmd/compile/internal/ssa/rewriteAMD64.go | 50 |
2 files changed, 53 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/_gen/AMD64.rules b/src/cmd/compile/internal/ssa/_gen/AMD64.rules index 2a4c59ebfc..0f7b0bb6d8 100644 --- a/src/cmd/compile/internal/ssa/_gen/AMD64.rules +++ b/src/cmd/compile/internal/ssa/_gen/AMD64.rules @@ -1583,6 +1583,9 @@ (MOVSDstore [off] {sym} ptr (MOVQi2f val) mem) => (MOVQstore [off] {sym} ptr val mem) (MOVSSstore [off] {sym} ptr (MOVLi2f val) mem) => (MOVLstore [off] {sym} ptr val mem) +(MOVSDstore [off] {sym} ptr (MOVSDconst [f]) mem) && f == f => (MOVQstore [off] {sym} ptr (MOVQconst [int64(math.Float64bits(f))]) mem) +(MOVSSstore [off] {sym} ptr (MOVSSconst [f]) mem) && f == f => (MOVLstore [off] {sym} ptr (MOVLconst [int32(math.Float32bits(f))]) mem) + // Load args directly into the register class where it will be used. // We do this by just modifying the type of the Arg. (MOVQf2i <t> (Arg <u> [off] {sym})) && t.Size() == u.Size() => @b.Func.Entry (Arg <t> [off] {sym}) diff --git a/src/cmd/compile/internal/ssa/rewriteAMD64.go b/src/cmd/compile/internal/ssa/rewriteAMD64.go index ba71189703..2670ba91b8 100644 --- a/src/cmd/compile/internal/ssa/rewriteAMD64.go +++ b/src/cmd/compile/internal/ssa/rewriteAMD64.go @@ -12304,6 +12304,8 @@ func rewriteValueAMD64_OpAMD64MOVSDstore(v *Value) bool { v_2 := v.Args[2] v_1 := v.Args[1] v_0 := v.Args[0] + b := v.Block + typ := &b.Func.Config.Types // match: (MOVSDstore [off1] {sym} (ADDQconst [off2] ptr) val mem) // cond: is32Bit(int64(off1)+int64(off2)) // result: (MOVSDstore [off1+off2] {sym} ptr val mem) @@ -12366,6 +12368,29 @@ func rewriteValueAMD64_OpAMD64MOVSDstore(v *Value) bool { v.AddArg3(ptr, val, mem) return true } + // match: (MOVSDstore [off] {sym} ptr (MOVSDconst [f]) mem) + // cond: f == f + // result: (MOVQstore [off] {sym} ptr (MOVQconst [int64(math.Float64bits(f))]) mem) + for { + off := auxIntToInt32(v.AuxInt) + sym := auxToSym(v.Aux) + ptr := v_0 + if v_1.Op != OpAMD64MOVSDconst { + break + } + f := auxIntToFloat64(v_1.AuxInt) + mem := v_2 + if !(f == f) { + break + } + v.reset(OpAMD64MOVQstore) + v.AuxInt = int32ToAuxInt(off) + v.Aux = symToAux(sym) + v0 := b.NewValue0(v.Pos, OpAMD64MOVQconst, typ.UInt64) + v0.AuxInt = int64ToAuxInt(int64(math.Float64bits(f))) + v.AddArg3(ptr, v0, mem) + return true + } return false } func rewriteValueAMD64_OpAMD64MOVSSload(v *Value) bool { @@ -12437,6 +12462,8 @@ func rewriteValueAMD64_OpAMD64MOVSSstore(v *Value) bool { v_2 := v.Args[2] v_1 := v.Args[1] v_0 := v.Args[0] + b := v.Block + typ := &b.Func.Config.Types // match: (MOVSSstore [off1] {sym} (ADDQconst [off2] ptr) val mem) // cond: is32Bit(int64(off1)+int64(off2)) // result: (MOVSSstore [off1+off2] {sym} ptr val mem) @@ -12499,6 +12526,29 @@ func rewriteValueAMD64_OpAMD64MOVSSstore(v *Value) bool { v.AddArg3(ptr, val, mem) return true } + // match: (MOVSSstore [off] {sym} ptr (MOVSSconst [f]) mem) + // cond: f == f + // result: (MOVLstore [off] {sym} ptr (MOVLconst [int32(math.Float32bits(f))]) mem) + for { + off := auxIntToInt32(v.AuxInt) + sym := auxToSym(v.Aux) + ptr := v_0 + if v_1.Op != OpAMD64MOVSSconst { + break + } + f := auxIntToFloat32(v_1.AuxInt) + mem := v_2 + if !(f == f) { + break + } + v.reset(OpAMD64MOVLstore) + v.AuxInt = int32ToAuxInt(off) + v.Aux = symToAux(sym) + v0 := b.NewValue0(v.Pos, OpAMD64MOVLconst, typ.UInt32) + v0.AuxInt = int32ToAuxInt(int32(math.Float32bits(f))) + v.AddArg3(ptr, v0, mem) + return true + } return false } func rewriteValueAMD64_OpAMD64MOVWQSX(v *Value) bool { |