From a19cf510af8182751fefc16ce962f91fe17c1e1b Mon Sep 17 00:00:00 2001 From: Cuong Manh Le Date: Sat, 24 Oct 2020 10:40:09 +0700 Subject: cmd/compile: defer lowering OANDNOT until SSA Currently, "x &^ y" gets rewriten into "x & ^y" during walk. It adds unnecessary complexity to other parts, which must aware about this. Instead, we can just implement "&^" in the conversion to SSA, so "&^" can be handled like other binary operators. However, this CL does not pass toolstash-check. It seems that implements "&^" in the conversion to SSA causes registers allocation change. With the parent: obj: 00212 (.../src/runtime/complex.go:47) MOVQ X0, AX obj: 00213 (.../src/runtime/complex.go:47) BTRQ $63, AX obj: 00214 (.../src/runtime/complex.go:47) MOVQ "".n(SP), CX obj: 00215 (.../src/runtime/complex.go:47) MOVQ $-9223372036854775808, DX obj: 00216 (.../src/runtime/complex.go:47) ANDQ DX, CX obj: 00217 (.../src/runtime/complex.go:47) ORQ AX, CX With this CL: obj: 00212 (.../src/runtime/complex.go:47) MOVQ X0, AX obj: 00213 (.../src/runtime/complex.go:47) BTRQ $63, AX obj: 00214 (.../src/runtime/complex.go:47) MOVQ $-9223372036854775808, CX obj: 00215 (.../src/runtime/complex.go:47) MOVQ "".n(SP), DX obj: 00216 (.../src/runtime/complex.go:47) ANDQ CX, DX obj: 00217 (.../src/runtime/complex.go:47) ORQ AX, DX Change-Id: I80acf8496a91be4804fb7ef3df04c19baae2754c Reviewed-on: https://go-review.googlesource.com/c/go/+/264660 Trust: Cuong Manh Le Run-TryBot: Cuong Manh Le TryBot-Result: Go Bot Reviewed-by: Matthew Dempsky --- src/cmd/compile/internal/gc/ssa.go | 5 +++++ src/cmd/compile/internal/gc/syntax.go | 2 +- src/cmd/compile/internal/gc/walk.go | 30 ++++++++++++------------------ test/bounds.go | 5 +++++ 4 files changed, 23 insertions(+), 19 deletions(-) diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go index a1b5a03687..4769c2c7d9 100644 --- a/src/cmd/compile/internal/gc/ssa.go +++ b/src/cmd/compile/internal/gc/ssa.go @@ -2472,6 +2472,11 @@ func (s *state) expr(n *Node) *ssa.Value { a := s.expr(n.Left) b := s.expr(n.Right) return s.newValue2(s.ssaOp(n.Op, n.Type), a.Type, a, b) + case OANDNOT: + a := s.expr(n.Left) + b := s.expr(n.Right) + b = s.newValue1(s.ssaOp(OBITNOT, b.Type), b.Type, b) + return s.newValue2(s.ssaOp(OAND, n.Type), a.Type, a, b) case OLSH, ORSH: a := s.expr(n.Left) b := s.expr(n.Right) diff --git a/src/cmd/compile/internal/gc/syntax.go b/src/cmd/compile/internal/gc/syntax.go index 83b5db834f..58de9b5e3f 100644 --- a/src/cmd/compile/internal/gc/syntax.go +++ b/src/cmd/compile/internal/gc/syntax.go @@ -142,7 +142,7 @@ const ( _, _ // second nodeInitorder bit _, nodeHasBreak _, nodeNoInline // used internally by inliner to indicate that a function call should not be inlined; set for OCALLFUNC and OCALLMETH only - _, nodeImplicit // implicit OADDR or ODEREF; ++/-- statement represented as OASOP; or ANDNOT lowered to OAND + _, nodeImplicit // implicit OADDR or ODEREF; ++/-- statement represented as OASOP _, nodeIsDDD // is the argument variadic _, nodeDiag // already printed error about this _, nodeColas // OAS resulting from := diff --git a/src/cmd/compile/internal/gc/walk.go b/src/cmd/compile/internal/gc/walk.go index 6ce3eda44b..927f6c4b1e 100644 --- a/src/cmd/compile/internal/gc/walk.go +++ b/src/cmd/compile/internal/gc/walk.go @@ -474,7 +474,7 @@ opswitch: ODEREF, OSPTR, OITAB, OIDATA, OADDR: n.Left = walkexpr(n.Left, init) - case OEFACE, OAND, OSUB, OMUL, OADD, OOR, OXOR, OLSH, ORSH: + case OEFACE, OAND, OANDNOT, OSUB, OMUL, OADD, OOR, OXOR, OLSH, ORSH: n.Left = walkexpr(n.Left, init) n.Right = walkexpr(n.Right, init) @@ -965,14 +965,6 @@ opswitch: fn := basicnames[param] + "to" + basicnames[result] n = conv(mkcall(fn, types.Types[result], init, conv(n.Left, types.Types[param])), n.Type) - case OANDNOT: - n.Left = walkexpr(n.Left, init) - n.Op = OAND - n.SetImplicit(true) // for walkCheckPtrArithmetic - n.Right = nod(OBITNOT, n.Right, nil) - n.Right = typecheck(n.Right, ctxExpr) - n.Right = walkexpr(n.Right, init) - case ODIV, OMOD: n.Left = walkexpr(n.Left, init) n.Right = walkexpr(n.Right, init) @@ -3609,14 +3601,20 @@ func bounded(n *Node, max int64) bool { } switch n.Op { - case OAND: + case OAND, OANDNOT: v := int64(-1) - if smallintconst(n.Left) { + switch { + case smallintconst(n.Left): v = n.Left.Int64Val() - } else if smallintconst(n.Right) { + case smallintconst(n.Right): v = n.Right.Int64Val() + if n.Op == OANDNOT { + v = ^v + if !sign { + v &= 1<