cmd/compile: add store to load forwarding rules on riscv64

Adds the equivalent integer variants of the floating point rules
added in CL 599235.

Change-Id: Ibe03c26383059821d99cea2337799e6416b4c581
Reviewed-on: https://go-review.googlesource.com/c/go/+/700175
Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Julian Zhu <jz531210@gmail.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>

2 files changed, 135 insertions, 0 deletions

diff --git a/src/cmd/compile/internal/ssa/_gen/RISCV64.rules b/src/cmd/compile/internal/ssa/_gen/RISCV64.rules
index 151f3412ce..821f822746 100644
--- a/src/cmd/compile/internal/ssa/_gen/RISCV64.rules
+++ b/src/cmd/compile/internal/ssa/_gen/RISCV64.rules
@@ -716,6 +716,8 @@
 (MOVWUreg <t> x:(MOVWload  [off] {sym} ptr mem)) && x.Uses == 1 && clobber(x) => @x.Block (MOVWUload <t> [off] {sym} ptr mem)
 
 // Replace load from same location as preceding store with copy.
+(MOV(D|W|H|B)load [off] {sym} ptr1 (MOV(D|W|H|B)store [off] {sym} ptr2 x _)) && isSamePtr(ptr1, ptr2) => (MOV(D|W|H|B)reg x)
+(MOV(W|H|B)Uload  [off] {sym} ptr1 (MOV(W|H|B)store   [off] {sym} ptr2 x _)) && isSamePtr(ptr1, ptr2) => (MOV(W|H|B)Ureg  x)
 (MOVDload  [off] {sym} ptr1 (FMOVDstore [off] {sym} ptr2 x _)) && isSamePtr(ptr1, ptr2) => (FMVXD x)
 (FMOVDload [off] {sym} ptr1 (MOVDstore  [off] {sym} ptr2 x _)) && isSamePtr(ptr1, ptr2) => (FMVDX x)
 (MOVWload  [off] {sym} ptr1 (FMOVWstore [off] {sym} ptr2 x _)) && isSamePtr(ptr1, ptr2) => (FMVXS x)
diff --git a/src/cmd/compile/internal/ssa/rewriteRISCV64.go b/src/cmd/compile/internal/ssa/rewriteRISCV64.go
index 1e80669672..e2c400b0c5 100644
--- a/src/cmd/compile/internal/ssa/rewriteRISCV64.go
+++ b/src/cmd/compile/internal/ssa/rewriteRISCV64.go
@@ -4740,6 +4740,25 @@ func rewriteValueRISCV64_OpRISCV64MOVBUload(v *Value) bool {
 		v.AddArg2(base, mem)
 		return true
 	}
+	// match: (MOVBUload [off] {sym} ptr1 (MOVBstore [off] {sym} ptr2 x _))
+	// cond: isSamePtr(ptr1, ptr2)
+	// result: (MOVBUreg x)
+	for {
+		off := auxIntToInt32(v.AuxInt)
+		sym := auxToSym(v.Aux)
+		ptr1 := v_0
+		if v_1.Op != OpRISCV64MOVBstore || auxIntToInt32(v_1.AuxInt) != off || auxToSym(v_1.Aux) != sym {
+			break
+		}
+		x := v_1.Args[1]
+		ptr2 := v_1.Args[0]
+		if !(isSamePtr(ptr1, ptr2)) {
+			break
+		}
+		v.reset(OpRISCV64MOVBUreg)
+		v.AddArg(x)
+		return true
+	}
 	return false
 }
 func rewriteValueRISCV64_OpRISCV64MOVBUreg(v *Value) bool {
@@ -5049,6 +5068,25 @@ func rewriteValueRISCV64_OpRISCV64MOVBload(v *Value) bool {
 		v.AddArg2(base, mem)
 		return true
 	}
+	// match: (MOVBload [off] {sym} ptr1 (MOVBstore [off] {sym} ptr2 x _))
+	// cond: isSamePtr(ptr1, ptr2)
+	// result: (MOVBreg x)
+	for {
+		off := auxIntToInt32(v.AuxInt)
+		sym := auxToSym(v.Aux)
+		ptr1 := v_0
+		if v_1.Op != OpRISCV64MOVBstore || auxIntToInt32(v_1.AuxInt) != off || auxToSym(v_1.Aux) != sym {
+			break
+		}
+		x := v_1.Args[1]
+		ptr2 := v_1.Args[0]
+		if !(isSamePtr(ptr1, ptr2)) {
+			break
+		}
+		v.reset(OpRISCV64MOVBreg)
+		v.AddArg(x)
+		return true
+	}
 	return false
 }
 func rewriteValueRISCV64_OpRISCV64MOVBreg(v *Value) bool {
@@ -5397,6 +5435,25 @@ func rewriteValueRISCV64_OpRISCV64MOVDload(v *Value) bool {
 		v.AddArg2(base, mem)
 		return true
 	}
+	// match: (MOVDload [off] {sym} ptr1 (MOVDstore [off] {sym} ptr2 x _))
+	// cond: isSamePtr(ptr1, ptr2)
+	// result: (MOVDreg x)
+	for {
+		off := auxIntToInt32(v.AuxInt)
+		sym := auxToSym(v.Aux)
+		ptr1 := v_0
+		if v_1.Op != OpRISCV64MOVDstore || auxIntToInt32(v_1.AuxInt) != off || auxToSym(v_1.Aux) != sym {
+			break
+		}
+		x := v_1.Args[1]
+		ptr2 := v_1.Args[0]
+		if !(isSamePtr(ptr1, ptr2)) {
+			break
+		}
+		v.reset(OpRISCV64MOVDreg)
+		v.AddArg(x)
+		return true
+	}
 	// match: (MOVDload [off] {sym} ptr1 (FMOVDstore [off] {sym} ptr2 x _))
 	// cond: isSamePtr(ptr1, ptr2)
 	// result: (FMVXD x)
@@ -5616,6 +5673,25 @@ func rewriteValueRISCV64_OpRISCV64MOVHUload(v *Value) bool {
 		v.AddArg2(base, mem)
 		return true
 	}
+	// match: (MOVHUload [off] {sym} ptr1 (MOVHstore [off] {sym} ptr2 x _))
+	// cond: isSamePtr(ptr1, ptr2)
+	// result: (MOVHUreg x)
+	for {
+		off := auxIntToInt32(v.AuxInt)
+		sym := auxToSym(v.Aux)
+		ptr1 := v_0
+		if v_1.Op != OpRISCV64MOVHstore || auxIntToInt32(v_1.AuxInt) != off || auxToSym(v_1.Aux) != sym {
+			break
+		}
+		x := v_1.Args[1]
+		ptr2 := v_1.Args[0]
+		if !(isSamePtr(ptr1, ptr2)) {
+			break
+		}
+		v.reset(OpRISCV64MOVHUreg)
+		v.AddArg(x)
+		return true
+	}
 	return false
 }
 func rewriteValueRISCV64_OpRISCV64MOVHUreg(v *Value) bool {
@@ -5782,6 +5858,25 @@ func rewriteValueRISCV64_OpRISCV64MOVHload(v *Value) bool {
 		v.AddArg2(base, mem)
 		return true
 	}
+	// match: (MOVHload [off] {sym} ptr1 (MOVHstore [off] {sym} ptr2 x _))
+	// cond: isSamePtr(ptr1, ptr2)
+	// result: (MOVHreg x)
+	for {
+		off := auxIntToInt32(v.AuxInt)
+		sym := auxToSym(v.Aux)
+		ptr1 := v_0
+		if v_1.Op != OpRISCV64MOVHstore || auxIntToInt32(v_1.AuxInt) != off || auxToSym(v_1.Aux) != sym {
+			break
+		}
+		x := v_1.Args[1]
+		ptr2 := v_1.Args[0]
+		if !(isSamePtr(ptr1, ptr2)) {
+			break
+		}
+		v.reset(OpRISCV64MOVHreg)
+		v.AddArg(x)
+		return true
+	}
 	return false
 }
 func rewriteValueRISCV64_OpRISCV64MOVHreg(v *Value) bool {
@@ -6141,6 +6236,25 @@ func rewriteValueRISCV64_OpRISCV64MOVWUload(v *Value) bool {
 		v.AddArg2(base, mem)
 		return true
 	}
+	// match: (MOVWUload [off] {sym} ptr1 (MOVWstore [off] {sym} ptr2 x _))
+	// cond: isSamePtr(ptr1, ptr2)
+	// result: (MOVWUreg x)
+	for {
+		off := auxIntToInt32(v.AuxInt)
+		sym := auxToSym(v.Aux)
+		ptr1 := v_0
+		if v_1.Op != OpRISCV64MOVWstore || auxIntToInt32(v_1.AuxInt) != off || auxToSym(v_1.Aux) != sym {
+			break
+		}
+		x := v_1.Args[1]
+		ptr2 := v_1.Args[0]
+		if !(isSamePtr(ptr1, ptr2)) {
+			break
+		}
+		v.reset(OpRISCV64MOVWUreg)
+		v.AddArg(x)
+		return true
+	}
 	// match: (MOVWUload [off] {sym} ptr1 (FMOVWstore [off] {sym} ptr2 x _))
 	// cond: isSamePtr(ptr1, ptr2)
 	// result: (MOVWUreg (FMVXS x))
@@ -6352,6 +6466,25 @@ func rewriteValueRISCV64_OpRISCV64MOVWload(v *Value) bool {
 		v.AddArg2(base, mem)
 		return true
 	}
+	// match: (MOVWload [off] {sym} ptr1 (MOVWstore [off] {sym} ptr2 x _))
+	// cond: isSamePtr(ptr1, ptr2)
+	// result: (MOVWreg x)
+	for {
+		off := auxIntToInt32(v.AuxInt)
+		sym := auxToSym(v.Aux)
+		ptr1 := v_0
+		if v_1.Op != OpRISCV64MOVWstore || auxIntToInt32(v_1.AuxInt) != off || auxToSym(v_1.Aux) != sym {
+			break
+		}
+		x := v_1.Args[1]
+		ptr2 := v_1.Args[0]
+		if !(isSamePtr(ptr1, ptr2)) {
+			break
+		}
+		v.reset(OpRISCV64MOVWreg)
+		v.AddArg(x)
+		return true
+	}
 	// match: (MOVWload [off] {sym} ptr1 (FMOVWstore [off] {sym} ptr2 x _))
 	// cond: isSamePtr(ptr1, ptr2)
 	// result: (FMVXS x)