cmd: use built-in min/max instead of bespoke versions

Now that we're bootstrapping from a toolchain that has min/max builtins.

Update #64751

Change-Id: I63eedf3cca00f56f62ca092949cb2dc61db03361
Reviewed-on: https://go-review.googlesource.com/c/go/+/610355
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/compile/internal/abt/avlint32.go

@@ -819,13 +819,6 @@ func (t *node32) leftToRoot() *node32 {
 	return left
 }
 
-func max(a, b int8) int8 {
-	if a > b {
-		return a
-	}
-	return b
-}
-
 func (t *node32) copy() *node32 {
 	u := *t
 	return &u

src/cmd/compile/internal/ssa/_gen/S390X.rules

@@ -703,10 +703,10 @@
 (CMP(W|WU) (MOVDconst [c]) x) => (InvertFlags (CMP(W|WU)const x [int32(c)]))
 
 // Match (x >> c) << d to 'rotate then insert selected bits [into zero]'.
-(SLDconst (SRDconst x [c]) [d]) => (RISBGZ x {s390x.NewRotateParams(uint8(max8(0, int8(c-d))), 63-d, uint8(int8(d-c)&63))})
+(SLDconst (SRDconst x [c]) [d]) => (RISBGZ x {s390x.NewRotateParams(uint8(max(0, int8(c-d))), 63-d, uint8(int8(d-c)&63))})
 
 // Match (x << c) >> d to 'rotate then insert selected bits [into zero]'.
-(SRDconst (SLDconst x [c]) [d]) => (RISBGZ x {s390x.NewRotateParams(d, uint8(min8(63, int8(63-c+d))), uint8(int8(c-d)&63))})
+(SRDconst (SLDconst x [c]) [d]) => (RISBGZ x {s390x.NewRotateParams(d, uint8(min(63, int8(63-c+d))), uint8(int8(c-d)&63))})
 
 // Absorb input zero extension into 'rotate then insert selected bits [into zero]'.
 (RISBGZ (MOVWZreg x) {r}) && r.InMerge(0xffffffff) != nil => (RISBGZ x {*r.InMerge(0xffffffff)})

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

@@ -73,20 +73,6 @@ type loopnest struct {
 	initializedChildren, initializedDepth, initializedExits bool
 }
 
-func min8(a, b int8) int8 {
-	if a < b {
-		return a
-	}
-	return b
-}
-
-func max8(a, b int8) int8 {
-	if a > b {
-		return a
-	}
-	return b
-}
-
 const (
 	blDEFAULT = 0
 	blMin     = blDEFAULT
@@ -143,7 +129,7 @@ func likelyadjust(f *Func) {
 			// and less influential than inferences from loop structure.
 		case BlockDefer:
 			local[b.ID] = blCALL
-			certain[b.ID] = max8(blCALL, certain[b.Succs[0].b.ID])
+			certain[b.ID] = max(blCALL, certain[b.Succs[0].b.ID])
 
 		default:
 			if len(b.Succs) == 1 {
@@ -157,7 +143,7 @@ func likelyadjust(f *Func) {
 				// tagged with call cost. Net effect is that loop entry is favored.
 				b0 := b.Succs[0].b.ID
 				b1 := b.Succs[1].b.ID
-				certain[b.ID] = min8(certain[b0], certain[b1])
+				certain[b.ID] = min(certain[b0], certain[b1])
 
 				l := b2l[b.ID]
 				l0 := b2l[b0]
@@ -223,7 +209,7 @@ func likelyadjust(f *Func) {
 			for _, v := range b.Values {
 				if opcodeTable[v.Op].call {
 					local[b.ID] = blCALL
-					certain[b.ID] = max8(blCALL, certain[b.Succs[0].b.ID])
+					certain[b.ID] = max(blCALL, certain[b.Succs[0].b.ID])
 					break
 				}
 			}

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

@@ -1737,13 +1737,13 @@ func (ft *factsTable) flowLimit(v *Value) bool {
 		// AND can only make the value smaller.
 		a := ft.limits[v.Args[0].ID]
 		b := ft.limits[v.Args[1].ID]
-		return ft.unsignedMax(v, minU(a.umax, b.umax))
+		return ft.unsignedMax(v, min(a.umax, b.umax))
 	case OpOr64, OpOr32, OpOr16, OpOr8:
 		// OR can only make the value bigger and can't flip bits proved to be zero in both inputs.
 		a := ft.limits[v.Args[0].ID]
 		b := ft.limits[v.Args[1].ID]
 		return ft.unsignedMinMax(v,
-			maxU(a.umin, b.umin),
+			max(a.umin, b.umin),
 			1<<bits.Len64(a.umax|b.umax)-1)
 	case OpXor64, OpXor32, OpXor16, OpXor8:
 		// XOR can't flip bits that are proved to be zero in both inputs.
@@ -1835,7 +1835,7 @@ func (ft *factsTable) flowLimit(v *Value) bool {
 		a := ft.limits[v.Args[0].ID]
 		b := ft.limits[v.Args[1].ID]
 		// Underflow in the arithmetic below is ok, it gives to MaxUint64 which does nothing to the limit.
-		return ft.unsignedMax(v, minU(a.umax, b.umax-1))
+		return ft.unsignedMax(v, min(a.umax, b.umax-1))
 	case OpDiv64, OpDiv32, OpDiv16, OpDiv8:
 		a := ft.limits[v.Args[0].ID]
 		b := ft.limits[v.Args[1].ID]
@@ -1871,8 +1871,8 @@ func (ft *factsTable) flowLimit(v *Value) bool {
 			l2 := ft.limits[a.ID]
 			l.min = min(l.min, l2.min)
 			l.max = max(l.max, l2.max)
-			l.umin = minU(l.umin, l2.umin)
+			l.umin = min(l.umin, l2.umin)
-			l.umax = maxU(l.umax, l2.umax)
+			l.umax = max(l.umax, l2.umax)
 		}
 		return ft.newLimit(v, l)
 	}

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

@@ -511,8 +511,8 @@ func (s *regAllocState) makeSpill(v *Value, b *Block) *Value {
 	vi := &s.values[v.ID]
 	if vi.spill != nil {
 		// Final block not known - keep track of subtree where restores reside.
-		vi.restoreMin = min32(vi.restoreMin, s.sdom[b.ID].entry)
+		vi.restoreMin = min(vi.restoreMin, s.sdom[b.ID].entry)
-		vi.restoreMax = max32(vi.restoreMax, s.sdom[b.ID].exit)
+		vi.restoreMax = max(vi.restoreMax, s.sdom[b.ID].exit)
 		return vi.spill
 	}
 	// Make a spill for v. We don't know where we want
@@ -2987,16 +2987,3 @@ func (d *desiredState) merge(x *desiredState) {
 		d.addList(e.ID, e.regs)
 	}
 }
-
-func min32(x, y int32) int32 {
-	if x < y {
-		return x
-	}
-	return y
-}
-func max32(x, y int32) int32 {
-	if x > y {
-		return x
-	}
-	return y
-}

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

@@ -1188,33 +1188,6 @@ func logRule(s string) {
 
 var ruleFile io.Writer
 
-// TODO: replace these with the built-in min/max once they are available
-// during bootstrap (when bootstrapping with 1.21 or later).
-func min(x, y int64) int64 {
-	if x < y {
-		return x
-	}
-	return y
-}
-func max(x, y int64) int64 {
-	if x > y {
-		return x
-	}
-	return y
-}
-func minU(x, y uint64) uint64 {
-	if x < y {
-		return x
-	}
-	return y
-}
-func maxU(x, y uint64) uint64 {
-	if x > y {
-		return x
-	}
-	return y
-}
-
 func isConstZero(v *Value) bool {
 	switch v.Op {
 	case OpConstNil:

src/cmd/compile/internal/ssa/rewriteS390X.go

@@ -12118,7 +12118,7 @@ func rewriteValueS390X_OpS390XSLD(v *Value) bool {
 func rewriteValueS390X_OpS390XSLDconst(v *Value) bool {
 	v_0 := v.Args[0]
 	// match: (SLDconst (SRDconst x [c]) [d])
-	// result: (RISBGZ x {s390x.NewRotateParams(uint8(max8(0, int8(c-d))), 63-d, uint8(int8(d-c)&63))})
+	// result: (RISBGZ x {s390x.NewRotateParams(uint8(max(0, int8(c-d))), 63-d, uint8(int8(d-c)&63))})
 	for {
 		d := auxIntToUint8(v.AuxInt)
 		if v_0.Op != OpS390XSRDconst {
@@ -12127,7 +12127,7 @@ func rewriteValueS390X_OpS390XSLDconst(v *Value) bool {
 		c := auxIntToUint8(v_0.AuxInt)
 		x := v_0.Args[0]
 		v.reset(OpS390XRISBGZ)
-		v.Aux = s390xRotateParamsToAux(s390x.NewRotateParams(uint8(max8(0, int8(c-d))), 63-d, uint8(int8(d-c)&63)))
+		v.Aux = s390xRotateParamsToAux(s390x.NewRotateParams(uint8(max(0, int8(c-d))), 63-d, uint8(int8(d-c)&63)))
 		v.AddArg(x)
 		return true
 	}
@@ -12874,7 +12874,7 @@ func rewriteValueS390X_OpS390XSRD(v *Value) bool {
 func rewriteValueS390X_OpS390XSRDconst(v *Value) bool {
 	v_0 := v.Args[0]
 	// match: (SRDconst (SLDconst x [c]) [d])
-	// result: (RISBGZ x {s390x.NewRotateParams(d, uint8(min8(63, int8(63-c+d))), uint8(int8(c-d)&63))})
+	// result: (RISBGZ x {s390x.NewRotateParams(d, uint8(min(63, int8(63-c+d))), uint8(int8(c-d)&63))})
 	for {
 		d := auxIntToUint8(v.AuxInt)
 		if v_0.Op != OpS390XSLDconst {
@@ -12883,7 +12883,7 @@ func rewriteValueS390X_OpS390XSRDconst(v *Value) bool {
 		c := auxIntToUint8(v_0.AuxInt)
 		x := v_0.Args[0]
 		v.reset(OpS390XRISBGZ)
-		v.Aux = s390xRotateParamsToAux(s390x.NewRotateParams(d, uint8(min8(63, int8(63-c+d))), uint8(int8(c-d)&63)))
+		v.Aux = s390xRotateParamsToAux(s390x.NewRotateParams(d, uint8(min(63, int8(63-c+d))), uint8(int8(c-d)&63)))
 		v.AddArg(x)
 		return true
 	}

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

@@ -3863,7 +3863,7 @@ func (s *state) condBranch(cond ir.Node, yes, no *ssa.Block, likely int8) {
 		cond := cond.(*ir.LogicalExpr)
 		mid := s.f.NewBlock(ssa.BlockPlain)
 		s.stmtList(cond.Init())
-		s.condBranch(cond.X, mid, no, max8(likely, 0))
+		s.condBranch(cond.X, mid, no, max(likely, 0))
 		s.startBlock(mid)
 		s.condBranch(cond.Y, yes, no, likely)
 		return
@@ -3877,7 +3877,7 @@ func (s *state) condBranch(cond ir.Node, yes, no *ssa.Block, likely int8) {
 		cond := cond.(*ir.LogicalExpr)
 		mid := s.f.NewBlock(ssa.BlockPlain)
 		s.stmtList(cond.Init())
-		s.condBranch(cond.X, yes, mid, min8(likely, 0))
+		s.condBranch(cond.X, yes, mid, min(likely, 0))
 		s.startBlock(mid)
 		s.condBranch(cond.Y, yes, no, likely)
 		return
@@ -7401,20 +7401,6 @@ func callTargetLSym(callee *ir.Name) *obj.LSym {
 	return callee.LinksymABI(callee.Func.ABI)
 }
 
-func min8(a, b int8) int8 {
-	if a < b {
-		return a
-	}
-	return b
-}
-
-func max8(a, b int8) int8 {
-	if a > b {
-		return a
-	}
-	return b
-}
-
 // deferStructFnField is the field index of _defer.fn.
 const deferStructFnField = 4
 

src/cmd/dist/util.go

@@ -405,13 +405,6 @@ func xgetgoarm() string {
 	return "7"
 }
 
-func min(a, b int) int {
-	if a < b {
-		return a
-	}
-	return b
-}
-
 // elfIsLittleEndian detects if the ELF file is little endian.
 func elfIsLittleEndian(fn string) bool {
 	// read the ELF file header to determine the endianness without using the