From 73df946d56c74384511a194dd01dbe099584fd1a Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 28 Apr 2024 15:14:23 +0200 Subject: Adding upstream version 1.16.10. Signed-off-by: Daniel Baumann --- src/cmd/internal/obj/s390x/condition_code.go | 126 +++++++++++++++++++++++++++ 1 file changed, 126 insertions(+) create mode 100644 src/cmd/internal/obj/s390x/condition_code.go (limited to 'src/cmd/internal/obj/s390x/condition_code.go') diff --git a/src/cmd/internal/obj/s390x/condition_code.go b/src/cmd/internal/obj/s390x/condition_code.go new file mode 100644 index 0000000..764fc5b --- /dev/null +++ b/src/cmd/internal/obj/s390x/condition_code.go @@ -0,0 +1,126 @@ +// Copyright 2019 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 s390x + +import ( + "fmt" +) + +// CCMask represents a 4-bit condition code mask. Bits that +// are not part of the mask should be 0. +// +// Condition code masks represent the 4 possible values of +// the 2-bit condition code as individual bits. Since IBM Z +// is a big-endian platform bits are numbered from left to +// right. The lowest value, 0, is represented by 8 (0b1000) +// and the highest value, 3, is represented by 1 (0b0001). +// +// Note that condition code values have different semantics +// depending on the instruction that set the condition code. +// The names given here assume that the condition code was +// set by an integer or floating point comparison. Other +// instructions may use these same codes to indicate +// different results such as a carry or overflow. +type CCMask uint8 + +const ( + Never CCMask = 0 // no-op + + // 1-bit masks + Equal CCMask = 1 << 3 + Less CCMask = 1 << 2 + Greater CCMask = 1 << 1 + Unordered CCMask = 1 << 0 + + // 2-bit masks + EqualOrUnordered CCMask = Equal | Unordered // not less and not greater + LessOrEqual CCMask = Less | Equal // ordered and not greater + LessOrGreater CCMask = Less | Greater // ordered and not equal + LessOrUnordered CCMask = Less | Unordered // not greater and not equal + GreaterOrEqual CCMask = Greater | Equal // ordered and not less + GreaterOrUnordered CCMask = Greater | Unordered // not less and not equal + + // 3-bit masks + NotEqual CCMask = Always ^ Equal + NotLess CCMask = Always ^ Less + NotGreater CCMask = Always ^ Greater + NotUnordered CCMask = Always ^ Unordered + + // 4-bit mask + Always CCMask = Equal | Less | Greater | Unordered + + // useful aliases + Carry CCMask = GreaterOrUnordered + NoCarry CCMask = LessOrEqual + Borrow CCMask = NoCarry + NoBorrow CCMask = Carry +) + +// Inverse returns the complement of the condition code mask. +func (c CCMask) Inverse() CCMask { + return c ^ Always +} + +// ReverseComparison swaps the bits at 0b0100 and 0b0010 in the mask, +// reversing the behavior of greater than and less than conditions. +func (c CCMask) ReverseComparison() CCMask { + r := c & EqualOrUnordered + if c&Less != 0 { + r |= Greater + } + if c&Greater != 0 { + r |= Less + } + return r +} + +func (c CCMask) String() string { + switch c { + // 0-bit mask + case Never: + return "Never" + + // 1-bit masks + case Equal: + return "Equal" + case Less: + return "Less" + case Greater: + return "Greater" + case Unordered: + return "Unordered" + + // 2-bit masks + case EqualOrUnordered: + return "EqualOrUnordered" + case LessOrEqual: + return "LessOrEqual" + case LessOrGreater: + return "LessOrGreater" + case LessOrUnordered: + return "LessOrUnordered" + case GreaterOrEqual: + return "GreaterOrEqual" + case GreaterOrUnordered: + return "GreaterOrUnordered" + + // 3-bit masks + case NotEqual: + return "NotEqual" + case NotLess: + return "NotLess" + case NotGreater: + return "NotGreater" + case NotUnordered: + return "NotUnordered" + + // 4-bit mask + case Always: + return "Always" + } + + // invalid + return fmt.Sprintf("Invalid (%#x)", c) +} -- cgit v1.2.3