[dev.ssa] cmd/compile: improve inBounds rewrite rules

Change-Id: Ia238187a89f820cd1620ab5acdbf1c8f003569b1
Reviewed-on: https://go-review.googlesource.com/13587Reviewed-by: Keith Randall <khr@golang.org>

src/cmd/compile/internal/ssa/gen/AMD64.rules

@@ -440,22 +440,22 @@
 (NE (InvertFlags cmp) yes no) -> (NE cmp yes no)
 
 // get rid of overflow code for constant shifts
-(SBBQcarrymask (CMPQconst [c] (MOVQconst [d]))) && inBounds(d, c) -> (MOVQconst [-1])
-(SBBQcarrymask (CMPQconst [c] (MOVQconst [d]))) && !inBounds(d, c) -> (MOVQconst [0])
-(SBBQcarrymask (CMPLconst [c] (MOVLconst [d]))) && inBounds(int64(int32(d)), int64(int32(c))) -> (MOVQconst [-1])
-(SBBQcarrymask (CMPLconst [c] (MOVLconst [d]))) && !inBounds(int64(int32(d)), int64(int32(c))) -> (MOVQconst [0])
-(SBBQcarrymask (CMPWconst [c] (MOVWconst [d]))) && inBounds(int64(int16(d)), int64(int16(c))) -> (MOVQconst [-1])
-(SBBQcarrymask (CMPWconst [c] (MOVWconst [d]))) && !inBounds(int64(int16(d)), int64(int16(c))) -> (MOVQconst [0])
-(SBBQcarrymask (CMPBconst [c] (MOVBconst [d]))) && inBounds(int64(int8(d)), int64(int8(c))) -> (MOVQconst [-1])
-(SBBQcarrymask (CMPBconst [c] (MOVBconst [d]))) && !inBounds(int64(int8(d)), int64(int8(c))) -> (MOVQconst [0])
-(SBBLcarrymask (CMPQconst [c] (MOVQconst [d]))) && inBounds(d, c) -> (MOVLconst [-1])
-(SBBLcarrymask (CMPQconst [c] (MOVQconst [d]))) && !inBounds(d, c) -> (MOVLconst [0])
-(SBBLcarrymask (CMPLconst [c] (MOVLconst [d]))) && inBounds(int64(int32(d)), int64(int32(c))) -> (MOVLconst [-1])
-(SBBLcarrymask (CMPLconst [c] (MOVLconst [d]))) && !inBounds(int64(int32(d)), int64(int32(c))) -> (MOVLconst [0])
-(SBBLcarrymask (CMPWconst [c] (MOVWconst [d]))) && inBounds(int64(int16(d)), int64(int16(c))) -> (MOVLconst [-1])
-(SBBLcarrymask (CMPWconst [c] (MOVWconst [d]))) && !inBounds(int64(int16(d)), int64(int16(c))) -> (MOVLconst [0])
-(SBBLcarrymask (CMPBconst [c] (MOVBconst [d]))) && inBounds(int64(int8(d)), int64(int8(c))) -> (MOVLconst [-1])
-(SBBLcarrymask (CMPBconst [c] (MOVBconst [d]))) && !inBounds(int64(int8(d)), int64(int8(c))) -> (MOVLconst [0])
+(SBBQcarrymask (CMPQconst [c] (MOVQconst [d]))) &&  inBounds64(d, c) -> (MOVQconst [-1])
+(SBBQcarrymask (CMPQconst [c] (MOVQconst [d]))) && !inBounds64(d, c) -> (MOVQconst [0])
+(SBBQcarrymask (CMPLconst [c] (MOVLconst [d]))) &&  inBounds32(d, c) -> (MOVQconst [-1])
+(SBBQcarrymask (CMPLconst [c] (MOVLconst [d]))) && !inBounds32(d, c) -> (MOVQconst [0])
+(SBBQcarrymask (CMPWconst [c] (MOVWconst [d]))) &&  inBounds16(d, c) -> (MOVQconst [-1])
+(SBBQcarrymask (CMPWconst [c] (MOVWconst [d]))) && !inBounds16(d, c) -> (MOVQconst [0])
+(SBBQcarrymask (CMPBconst [c] (MOVBconst [d]))) &&  inBounds8(d, c)  -> (MOVQconst [-1])
+(SBBQcarrymask (CMPBconst [c] (MOVBconst [d]))) && !inBounds8(d, c)  -> (MOVQconst [0])
+(SBBLcarrymask (CMPQconst [c] (MOVQconst [d]))) &&  inBounds64(d, c) -> (MOVLconst [-1])
+(SBBLcarrymask (CMPQconst [c] (MOVQconst [d]))) && !inBounds64(d, c) -> (MOVLconst [0])
+(SBBLcarrymask (CMPLconst [c] (MOVLconst [d]))) &&  inBounds32(d, c) -> (MOVLconst [-1])
+(SBBLcarrymask (CMPLconst [c] (MOVLconst [d]))) && !inBounds32(d, c) -> (MOVLconst [0])
+(SBBLcarrymask (CMPWconst [c] (MOVWconst [d]))) &&  inBounds16(d, c) -> (MOVLconst [-1])
+(SBBLcarrymask (CMPWconst [c] (MOVWconst [d]))) && !inBounds16(d, c) -> (MOVLconst [0])
+(SBBLcarrymask (CMPBconst [c] (MOVBconst [d]))) &&  inBounds8(d, c)  -> (MOVLconst [-1])
+(SBBLcarrymask (CMPBconst [c] (MOVBconst [d]))) && !inBounds8(d, c)  -> (MOVLconst [0])
 (ANDQconst [0] _)                 -> (MOVQconst [0])
 (ANDLconst [c] _) && int32(c)==0  -> (MOVLconst [0])
 (ANDWconst [c] _) && int16(c)==0  -> (MOVWconst [0])

src/cmd/compile/internal/ssa/gen/generic.rules

@@ -24,7 +24,10 @@
 (AddPtr (ConstPtr [c]) (ConstPtr [d])) -> (ConstPtr [c+d])
 (Mul64 (Const64 [c]) (Const64 [d])) -> (Const64 [c*d])
 (MulPtr (ConstPtr [c]) (ConstPtr [d])) -> (ConstPtr [c*d])
-(IsInBounds (ConstPtr [c]) (ConstPtr [d])) -> (ConstPtr {inBounds(c,d)})
+(IsInBounds (Const32 [c]) (Const32 [d])) -> (ConstBool {inBounds32(c,d)})
+(IsInBounds (Const64 [c]) (Const64 [d])) -> (ConstBool {inBounds64(c,d)})
+(IsInBounds (ConstPtr [c]) (ConstPtr [d])) && config.PtrSize == 4 -> (ConstBool {inBounds32(c,d)})
+(IsInBounds (ConstPtr [c]) (ConstPtr [d])) && config.PtrSize == 8 -> (ConstBool {inBounds64(c,d)})
 (Eq64 x x) -> (ConstBool {true})
 (Eq32 x x) -> (ConstBool {true})
 (Eq16 x x) -> (ConstBool {true})

src/cmd/compile/internal/ssa/rewrite.go

@@ -125,9 +125,10 @@ func mergeSym(x, y interface{}) interface{} {
 	return nil
 }
 
-func inBounds(idx, len int64) bool {
-	return idx >= 0 && idx < len
-}
+func inBounds8(idx, len int64) bool  { return int8(idx) >= 0 && int8(idx) < int8(len) }
+func inBounds16(idx, len int64) bool { return int16(idx) >= 0 && int16(idx) < int16(len) }
+func inBounds32(idx, len int64) bool { return int32(idx) >= 0 && int32(idx) < int32(len) }
+func inBounds64(idx, len int64) bool { return idx >= 0 && idx < len }
 
 // log2 returns logarithm in base of n.
 // expects n to be a power of 2.

src/cmd/compile/internal/ssa/rewritegeneric.go

@@ -311,27 +311,99 @@ func rewriteValuegeneric(v *Value, config *Config) bool {
 	end540dc8dfbc66adcd3db2d7e819c534f6:
 		;
 	case OpIsInBounds:
-		// match: (IsInBounds (ConstPtr [c]) (ConstPtr [d]))
+		// match: (IsInBounds (Const32 [c]) (Const32 [d]))
+		// cond:
+		// result: (ConstBool {inBounds32(c,d)})
+		{
+			if v.Args[0].Op != OpConst32 {
+				goto endc3396bf88b56276e1691abe62811dba5
+			}
+			c := v.Args[0].AuxInt
+			if v.Args[1].Op != OpConst32 {
+				goto endc3396bf88b56276e1691abe62811dba5
+			}
+			d := v.Args[1].AuxInt
+			v.Op = OpConstBool
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.Aux = inBounds32(c, d)
+			return true
+		}
+		goto endc3396bf88b56276e1691abe62811dba5
+	endc3396bf88b56276e1691abe62811dba5:
+		;
+		// match: (IsInBounds (Const64 [c]) (Const64 [d]))
 		// cond:
-		// result: (ConstPtr {inBounds(c,d)})
+		// result: (ConstBool {inBounds64(c,d)})
+		{
+			if v.Args[0].Op != OpConst64 {
+				goto end0b4b8178a54662835b00bfa503cf879a
+			}
+			c := v.Args[0].AuxInt
+			if v.Args[1].Op != OpConst64 {
+				goto end0b4b8178a54662835b00bfa503cf879a
+			}
+			d := v.Args[1].AuxInt
+			v.Op = OpConstBool
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.Aux = inBounds64(c, d)
+			return true
+		}
+		goto end0b4b8178a54662835b00bfa503cf879a
+	end0b4b8178a54662835b00bfa503cf879a:
+		;
+		// match: (IsInBounds (ConstPtr [c]) (ConstPtr [d]))
+		// cond: config.PtrSize == 4
+		// result: (ConstBool {inBounds32(c,d)})
 		{
 			if v.Args[0].Op != OpConstPtr {
-				goto enddfd340bc7103ca323354aec96b113c23
+				goto end2c6938f68a67e08dbd96edb1e693e549
 			}
 			c := v.Args[0].AuxInt
 			if v.Args[1].Op != OpConstPtr {
-				goto enddfd340bc7103ca323354aec96b113c23
+				goto end2c6938f68a67e08dbd96edb1e693e549
 			}
 			d := v.Args[1].AuxInt
-			v.Op = OpConstPtr
+			if !(config.PtrSize == 4) {
+				goto end2c6938f68a67e08dbd96edb1e693e549
+			}
+			v.Op = OpConstBool
+			v.AuxInt = 0
+			v.Aux = nil
+			v.resetArgs()
+			v.Aux = inBounds32(c, d)
+			return true
+		}
+		goto end2c6938f68a67e08dbd96edb1e693e549
+	end2c6938f68a67e08dbd96edb1e693e549:
+		;
+		// match: (IsInBounds (ConstPtr [c]) (ConstPtr [d]))
+		// cond: config.PtrSize == 8
+		// result: (ConstBool {inBounds64(c,d)})
+		{
+			if v.Args[0].Op != OpConstPtr {
+				goto end84d6ae817944985f572ecaac51999d6c
+			}
+			c := v.Args[0].AuxInt
+			if v.Args[1].Op != OpConstPtr {
+				goto end84d6ae817944985f572ecaac51999d6c
+			}
+			d := v.Args[1].AuxInt
+			if !(config.PtrSize == 8) {
+				goto end84d6ae817944985f572ecaac51999d6c
+			}
+			v.Op = OpConstBool
 			v.AuxInt = 0
 			v.Aux = nil
 			v.resetArgs()
-			v.Aux = inBounds(c, d)
+			v.Aux = inBounds64(c, d)
 			return true
 		}
-		goto enddfd340bc7103ca323354aec96b113c23
-	enddfd340bc7103ca323354aec96b113c23:
+		goto end84d6ae817944985f572ecaac51999d6c
+	end84d6ae817944985f572ecaac51999d6c:
 		;
 	case OpLoad:
 		// match: (Load <t> ptr mem)