diff --git a/src/cmd/compile/internal/ssa/_gen/generic.rules b/src/cmd/compile/internal/ssa/_gen/generic.rules index 58872ca85a3..b16aa473cd5 100644 --- a/src/cmd/compile/internal/ssa/_gen/generic.rules +++ b/src/cmd/compile/internal/ssa/_gen/generic.rules @@ -2079,6 +2079,9 @@ && warnRule(fe.Debug_checknil(), v, "removed nil check") => ptr +// .dict args are always non-nil. +(NilCheck ptr:(Arg {sym}) _) && isDictArgSym(sym) => ptr + // Nil checks of nil checks are redundant. // See comment at the end of https://go-review.googlesource.com/c/go/+/537775. (NilCheck ptr:(NilCheck _ _) _ ) => ptr diff --git a/src/cmd/compile/internal/ssa/rewrite.go b/src/cmd/compile/internal/ssa/rewrite.go index 6d83ba56531..880c2223ef2 100644 --- a/src/cmd/compile/internal/ssa/rewrite.go +++ b/src/cmd/compile/internal/ssa/rewrite.go @@ -6,9 +6,11 @@ package ssa import ( "cmd/compile/internal/base" + "cmd/compile/internal/ir" "cmd/compile/internal/logopt" "cmd/compile/internal/reflectdata" "cmd/compile/internal/rttype" + "cmd/compile/internal/typecheck" "cmd/compile/internal/types" "cmd/internal/obj" "cmd/internal/obj/s390x" @@ -2744,3 +2746,7 @@ func panicBoundsCToAux(p PanicBoundsC) Aux { func panicBoundsCCToAux(p PanicBoundsCC) Aux { return p } + +func isDictArgSym(sym Sym) bool { + return sym.(*ir.Name).Sym().Name == typecheck.LocalDictName +} diff --git a/src/cmd/compile/internal/ssa/rewritegeneric.go b/src/cmd/compile/internal/ssa/rewritegeneric.go index 7e23194e6ab..5e0135be3a5 100644 --- a/src/cmd/compile/internal/ssa/rewritegeneric.go +++ b/src/cmd/compile/internal/ssa/rewritegeneric.go @@ -21393,6 +21393,21 @@ func rewriteValuegeneric_OpNilCheck(v *Value) bool { v.copyOf(ptr) return true } + // match: (NilCheck ptr:(Arg {sym}) _) + // cond: isDictArgSym(sym) + // result: ptr + for { + ptr := v_0 + if ptr.Op != OpArg { + break + } + sym := auxToSym(ptr.Aux) + if !(isDictArgSym(sym)) { + break + } + v.copyOf(ptr) + return true + } // match: (NilCheck ptr:(NilCheck _ _) _ ) // result: ptr for { diff --git a/test/codegen/generics.go b/test/codegen/generics.go new file mode 100644 index 00000000000..45c4ca8d6ae --- /dev/null +++ b/test/codegen/generics.go @@ -0,0 +1,40 @@ +// asmcheck + +// Copyright 2025 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package codegen + +import "cmp" + +func isNaN[T cmp.Ordered](x T) bool { + return x != x +} + +func compare[T cmp.Ordered](x, y T) int { + // amd64:-"TESTB" + // arm64:-"MOVB" + xNaN := isNaN(x) + yNaN := isNaN(y) + if xNaN { + if yNaN { + return 0 + } + return -1 + } + if yNaN { + return +1 + } + if x < y { + return -1 + } + if x > y { + return +1 + } + return 0 +} + +func usesCompare(a, b int) int { + return compare(a, b) +}