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	 18ebd9195a
			
		
	
	18ebd9195a
	
	
	
		
			
			This patch introduces some changes, particularly to arm64SwitchStack which fixes the test when running on linux/arm64. The changes causes the same test to fail on darwin/m1 so temporarily keeping both versions. Next step should be to refactor and unify the two so they both work with the same function. Fixes #2340
		
			
				
	
	
		
			472 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			472 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| package proc
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| 
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| import (
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| 	"bytes"
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| 	"encoding/binary"
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| 	"fmt"
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| 	"io"
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| 	"math"
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| 	"strings"
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| 
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| 	"github.com/go-delve/delve/pkg/dwarf/frame"
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| 	"github.com/go-delve/delve/pkg/dwarf/op"
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| 	"github.com/go-delve/delve/pkg/dwarf/regnum"
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| )
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| 
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| var amd64BreakInstruction = []byte{0xCC}
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| 
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| // AMD64Arch returns an initialized AMD64
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| // struct.
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| func AMD64Arch(goos string) *Arch {
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| 	return &Arch{
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| 		Name:                             "amd64",
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| 		ptrSize:                          8,
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| 		maxInstructionLength:             15,
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| 		breakpointInstruction:            amd64BreakInstruction,
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| 		breakInstrMovesPC:                true,
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| 		derefTLS:                         goos == "windows",
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| 		prologues:                        prologuesAMD64,
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| 		fixFrameUnwindContext:            amd64FixFrameUnwindContext,
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| 		switchStack:                      amd64SwitchStack,
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| 		regSize:                          amd64RegSize,
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| 		RegistersToDwarfRegisters:        amd64RegistersToDwarfRegisters,
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| 		addrAndStackRegsToDwarfRegisters: amd64AddrAndStackRegsToDwarfRegisters,
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| 		DwarfRegisterToString:            amd64DwarfRegisterToString,
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| 		inhibitStepInto:                  func(*BinaryInfo, uint64) bool { return false },
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| 		asmDecode:                        amd64AsmDecode,
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| 		PCRegNum:                         regnum.AMD64_Rip,
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| 		SPRegNum:                         regnum.AMD64_Rsp,
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| 		BPRegNum:                         regnum.AMD64_Rbp,
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| 		ContextRegNum:                    regnum.AMD64_Rdx,
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| 		asmRegisters:                     amd64AsmRegisters,
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| 		RegisterNameToDwarf:              nameToDwarfFunc(regnum.AMD64NameToDwarf),
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| 		RegnumToString:                   regnum.AMD64ToName,
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| 		debugCallMinStackSize:            256,
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| 		maxRegArgBytes:                   9*8 + 15*8,
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| 	}
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| }
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| 
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| func amd64FixFrameUnwindContext(fctxt *frame.FrameContext, pc uint64, bi *BinaryInfo) *frame.FrameContext {
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| 	a := bi.Arch
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| 	if a.sigreturnfn == nil {
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| 		a.sigreturnfn = bi.LookupFunc["runtime.sigreturn"]
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| 	}
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| 
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| 	if fctxt == nil || (a.sigreturnfn != nil && pc >= a.sigreturnfn.Entry && pc < a.sigreturnfn.End) {
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| 		// When there's no frame descriptor entry use BP (the frame pointer) instead
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| 		// - return register is [bp + a.PtrSize()] (i.e. [cfa-a.PtrSize()])
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| 		// - cfa is bp + a.PtrSize()*2
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| 		// - bp is [bp] (i.e. [cfa-a.PtrSize()*2])
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| 		// - sp is cfa
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| 
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| 		// When the signal handler runs it will move the execution to the signal
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| 		// handling stack (installed using the sigaltstack system call).
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| 		// This isn't a proper stack switch: the pointer to g in TLS will still
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| 		// refer to whatever g was executing on that thread before the signal was
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| 		// received.
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| 		// Since go did not execute a stack switch the previous value of sp, pc
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| 		// and bp is not saved inside g.sched, as it normally would.
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| 		// The only way to recover is to either read sp/pc from the signal context
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| 		// parameter (the ucontext_t* parameter) or to unconditionally follow the
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| 		// frame pointer when we get to runtime.sigreturn (which is what we do
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| 		// here).
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| 
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| 		return &frame.FrameContext{
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| 			RetAddrReg: regnum.AMD64_Rip,
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| 			Regs: map[uint64]frame.DWRule{
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| 				regnum.AMD64_Rip: {
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| 					Rule:   frame.RuleOffset,
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| 					Offset: int64(-a.PtrSize()),
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| 				},
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| 				regnum.AMD64_Rbp: {
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| 					Rule:   frame.RuleOffset,
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| 					Offset: int64(-2 * a.PtrSize()),
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| 				},
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| 				regnum.AMD64_Rsp: {
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| 					Rule:   frame.RuleValOffset,
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| 					Offset: 0,
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| 				},
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| 			},
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| 			CFA: frame.DWRule{
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| 				Rule:   frame.RuleCFA,
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| 				Reg:    regnum.AMD64_Rbp,
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| 				Offset: int64(2 * a.PtrSize()),
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| 			},
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| 		}
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| 	}
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| 
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| 	if a.crosscall2fn == nil {
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| 		a.crosscall2fn = bi.LookupFunc["crosscall2"]
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| 	}
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| 
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| 	if a.crosscall2fn != nil && pc >= a.crosscall2fn.Entry && pc < a.crosscall2fn.End {
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| 		rule := fctxt.CFA
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| 		if rule.Offset == crosscall2SPOffsetBad {
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| 			switch bi.GOOS {
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| 			case "windows":
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| 				rule.Offset += crosscall2SPOffsetWindowsAMD64
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| 			default:
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| 				rule.Offset += crosscall2SPOffset
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| 			}
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| 		}
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| 		fctxt.CFA = rule
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| 	}
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| 
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| 	// We assume that RBP is the frame pointer and we want to keep it updated,
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| 	// so that we can use it to unwind the stack even when we encounter frames
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| 	// without descriptor entries.
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| 	// If there isn't a rule already we emit one.
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| 	if fctxt.Regs[regnum.AMD64_Rbp].Rule == frame.RuleUndefined {
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| 		fctxt.Regs[regnum.AMD64_Rbp] = frame.DWRule{
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| 			Rule:   frame.RuleFramePointer,
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| 			Reg:    regnum.AMD64_Rbp,
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| 			Offset: 0,
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| 		}
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| 	}
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| 
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| 	return fctxt
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| }
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| 
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| // cgocallSPOffsetSaveSlot is the offset from systemstack.SP where
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| // (goroutine.SP - StackHi) is saved in runtime.asmcgocall after the stack
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| // switch happens.
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| const amd64cgocallSPOffsetSaveSlot = 0x28
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| 
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| func amd64SwitchStack(it *stackIterator, _ *op.DwarfRegisters) bool {
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| 	if it.frame.Current.Fn == nil {
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| 		if it.systemstack && it.g != nil && it.top {
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| 			it.switchToGoroutineStack()
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| 			return true
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| 		}
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| 		return false
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| 	}
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| 	switch it.frame.Current.Fn.Name {
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| 	case "runtime.asmcgocall":
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| 		if it.top || !it.systemstack {
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| 			return false
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| 		}
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| 
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| 		// This function is called by a goroutine to execute a C function and
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| 		// switches from the goroutine stack to the system stack.
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| 		// Since we are unwinding the stack from callee to caller we have to switch
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| 		// from the system stack to the goroutine stack.
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| 		off, _ := readIntRaw(it.mem, uint64(it.regs.SP()+amd64cgocallSPOffsetSaveSlot), int64(it.bi.Arch.PtrSize())) // reads "offset of SP from StackHi" from where runtime.asmcgocall saved it
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| 		oldsp := it.regs.SP()
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| 		it.regs.Reg(it.regs.SPRegNum).Uint64Val = uint64(int64(it.stackhi) - off)
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| 
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| 		// runtime.asmcgocall can also be called from inside the system stack,
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| 		// in that case no stack switch actually happens
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| 		if it.regs.SP() == oldsp {
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| 			return false
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| 		}
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| 		it.systemstack = false
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| 
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| 		// advances to the next frame in the call stack
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| 		it.frame.addrret = uint64(int64(it.regs.SP()) + int64(it.bi.Arch.PtrSize()))
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| 		it.frame.Ret, _ = readUintRaw(it.mem, it.frame.addrret, int64(it.bi.Arch.PtrSize()))
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| 		it.pc = it.frame.Ret
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| 
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| 		it.top = false
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| 		return true
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| 
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| 	case "runtime.cgocallback_gofunc", "runtime.cgocallback":
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| 		// For a detailed description of how this works read the long comment at
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| 		// the start of $GOROOT/src/runtime/cgocall.go and the source code of
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| 		// runtime.cgocallback_gofunc in $GOROOT/src/runtime/asm_amd64.s
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| 		//
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| 		// When a C functions calls back into go it will eventually call into
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| 		// runtime.cgocallback_gofunc which is the function that does the stack
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| 		// switch from the system stack back into the goroutine stack
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| 		// Since we are going backwards on the stack here we see the transition
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| 		// as goroutine stack -> system stack.
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| 		if it.top || it.systemstack {
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| 			return false
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| 		}
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| 
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| 		it.loadG0SchedSP()
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| 		if it.g0_sched_sp <= 0 {
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| 			return false
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| 		}
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| 		// entering the system stack
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| 		it.regs.Reg(it.regs.SPRegNum).Uint64Val = it.g0_sched_sp
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| 		// reads the previous value of g0.sched.sp that runtime.cgocallback_gofunc saved on the stack
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| 		it.g0_sched_sp, _ = readUintRaw(it.mem, uint64(it.regs.SP()), int64(it.bi.Arch.PtrSize()))
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| 		it.top = false
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| 		callFrameRegs, ret, retaddr := it.advanceRegs()
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| 		frameOnSystemStack := it.newStackframe(ret, retaddr)
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| 		it.pc = frameOnSystemStack.Ret
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| 		it.regs = callFrameRegs
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| 		it.systemstack = true
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| 
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| 		return true
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| 
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| 	case "runtime.goexit", "runtime.rt0_go", "runtime.mcall":
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| 		// Look for "top of stack" functions.
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| 		it.atend = true
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| 		return true
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| 
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| 	case "runtime.mstart":
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| 		// Calls to runtime.systemstack will switch to the systemstack then:
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| 		// 1. alter the goroutine stack so that it looks like systemstack_switch
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| 		//    was called
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| 		// 2. alter the system stack so that it looks like the bottom-most frame
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| 		//    belongs to runtime.mstart
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| 		// If we find a runtime.mstart frame on the system stack of a goroutine
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| 		// parked on runtime.systemstack_switch we assume runtime.systemstack was
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| 		// called and continue tracing from the parked position.
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| 
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| 		if it.top || !it.systemstack || it.g == nil {
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| 			return false
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| 		}
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| 		if fn := it.bi.PCToFunc(it.g.PC); fn == nil || fn.Name != "runtime.systemstack_switch" {
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| 			return false
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| 		}
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| 
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| 		it.switchToGoroutineStack()
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| 		return true
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| 
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| 	default:
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| 		if it.systemstack && it.top && it.g != nil && strings.HasPrefix(it.frame.Current.Fn.Name, "runtime.") && it.frame.Current.Fn.Name != "runtime.throw" && it.frame.Current.Fn.Name != "runtime.fatalthrow" {
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| 			// The runtime switches to the system stack in multiple places.
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| 			// This usually happens through a call to runtime.systemstack but there
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| 			// are functions that switch to the system stack manually (for example
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| 			// runtime.morestack).
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| 			// Since we are only interested in printing the system stack for cgo
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| 			// calls we switch directly to the goroutine stack if we detect that the
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| 			// function at the top of the stack is a runtime function.
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| 			//
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| 			// The function "runtime.throw" is deliberately excluded from this
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| 			// because it can end up in the stack during a cgo call and switching to
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| 			// the goroutine stack will exclude all the C functions from the stack
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| 			// trace.
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| 			it.switchToGoroutineStack()
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| 			return true
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| 		}
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| 
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| 		return false
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| 	}
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| }
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| 
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| // amd64RegSize returns the size (in bytes) of register regnum.
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| // The mapping between hardware registers and DWARF registers is specified
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| // in the System V ABI AMD64 Architecture Processor Supplement page 57,
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| // figure 3.36
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| // https://www.uclibc.org/docs/psABI-x86_64.pdf
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| func amd64RegSize(rn uint64) int {
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| 	// XMM registers
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| 	if rn > regnum.AMD64_Rip && rn <= 32 {
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| 		return 16
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| 	}
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| 	// x87 registers
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| 	if rn >= 33 && rn <= 40 {
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| 		return 10
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| 	}
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| 	return 8
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| }
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| 
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| func amd64RegistersToDwarfRegisters(staticBase uint64, regs Registers) *op.DwarfRegisters {
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| 	dregs := initDwarfRegistersFromSlice(int(regnum.AMD64MaxRegNum()), regs, regnum.AMD64NameToDwarf)
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| 	dr := op.NewDwarfRegisters(staticBase, dregs, binary.LittleEndian, regnum.AMD64_Rip, regnum.AMD64_Rsp, regnum.AMD64_Rbp, 0)
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| 	dr.SetLoadMoreCallback(loadMoreDwarfRegistersFromSliceFunc(dr, regs, regnum.AMD64NameToDwarf))
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| 	return dr
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| }
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| 
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| func initDwarfRegistersFromSlice(maxRegs int, regs Registers, nameToDwarf map[string]int) []*op.DwarfRegister {
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| 	dregs := make([]*op.DwarfRegister, maxRegs+1)
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| 	regslice, _ := regs.Slice(false)
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| 	for _, reg := range regslice {
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| 		if dwarfReg, ok := nameToDwarf[strings.ToLower(reg.Name)]; ok {
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| 			dregs[dwarfReg] = reg.Reg
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| 		}
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| 	}
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| 	return dregs
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| }
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| 
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| func loadMoreDwarfRegistersFromSliceFunc(dr *op.DwarfRegisters, regs Registers, nameToDwarf map[string]int) func() {
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| 	return func() {
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| 		regslice, err := regs.Slice(true)
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| 		dr.FloatLoadError = err
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| 		for _, reg := range regslice {
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| 			name := strings.ToLower(reg.Name)
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| 			if dwarfReg, ok := nameToDwarf[name]; ok {
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| 				dr.AddReg(uint64(dwarfReg), reg.Reg)
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| 			} else if reg.Reg.Bytes != nil && (strings.HasPrefix(name, "ymm") || strings.HasPrefix(name, "zmm")) {
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| 				xmmIdx, ok := nameToDwarf["x"+name[1:]]
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| 				if !ok {
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| 					continue
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| 				}
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| 				xmmReg := dr.Reg(uint64(xmmIdx))
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| 				if xmmReg == nil || xmmReg.Bytes == nil {
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| 					continue
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| 				}
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| 				nb := make([]byte, 0, len(xmmReg.Bytes)+len(reg.Reg.Bytes))
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| 				nb = append(nb, xmmReg.Bytes...)
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| 				nb = append(nb, reg.Reg.Bytes...)
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| 				xmmReg.Bytes = nb
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| 			}
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| 		}
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| 	}
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| }
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| 
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| func amd64AddrAndStackRegsToDwarfRegisters(staticBase, pc, sp, bp, lr uint64) op.DwarfRegisters {
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| 	dregs := make([]*op.DwarfRegister, regnum.AMD64_Rip+1)
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| 	dregs[regnum.AMD64_Rip] = op.DwarfRegisterFromUint64(pc)
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| 	dregs[regnum.AMD64_Rsp] = op.DwarfRegisterFromUint64(sp)
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| 	dregs[regnum.AMD64_Rbp] = op.DwarfRegisterFromUint64(bp)
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| 
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| 	return *op.NewDwarfRegisters(staticBase, dregs, binary.LittleEndian, regnum.AMD64_Rip, regnum.AMD64_Rsp, regnum.AMD64_Rbp, 0)
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| }
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| 
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| func amd64DwarfRegisterToString(i int, reg *op.DwarfRegister) (name string, floatingPoint bool, repr string) {
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| 	name = regnum.AMD64ToName(uint64(i))
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| 
 | |
| 	if reg == nil {
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| 		return name, false, ""
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| 	}
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| 
 | |
| 	switch n := strings.ToLower(name); n {
 | |
| 	case "rflags":
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| 		return name, false, eflagsDescription.Describe(reg.Uint64Val, 64)
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| 
 | |
| 	case "cw", "sw", "tw", "fop":
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| 		return name, true, fmt.Sprintf("%#04x", reg.Uint64Val)
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| 
 | |
| 	case "mxcsr_mask":
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| 		return name, true, fmt.Sprintf("%#08x", reg.Uint64Val)
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| 
 | |
| 	case "mxcsr":
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| 		return name, true, mxcsrDescription.Describe(reg.Uint64Val, 32)
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| 
 | |
| 	default:
 | |
| 		if reg.Bytes != nil && strings.HasPrefix(n, "xmm") {
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| 			return name, true, formatSSEReg(name, reg.Bytes)
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| 		} else if reg.Bytes != nil && strings.HasPrefix(n, "st(") {
 | |
| 			return name, true, formatX87Reg(reg.Bytes)
 | |
| 		} else if reg.Bytes == nil || (reg.Bytes != nil && len(reg.Bytes) <= 8) {
 | |
| 			return name, false, fmt.Sprintf("%#016x", reg.Uint64Val)
 | |
| 		} else {
 | |
| 			return name, false, fmt.Sprintf("%#x", reg.Bytes)
 | |
| 		}
 | |
| 	}
 | |
| }
 | |
| 
 | |
| func formatSSEReg(name string, reg []byte) string {
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| 	out := new(bytes.Buffer)
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| 	formatSSERegInternal(reg, out)
 | |
| 	if len(reg) < 32 {
 | |
| 		return out.String()
 | |
| 	}
 | |
| 
 | |
| 	fmt.Fprintf(out, "\n\t[%sh] ", "Y"+name[1:])
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| 	formatSSERegInternal(reg[16:], out)
 | |
| 
 | |
| 	if len(reg) < 64 {
 | |
| 		return out.String()
 | |
| 	}
 | |
| 
 | |
| 	fmt.Fprintf(out, "\n\t[%shl] ", "Z"+name[1:])
 | |
| 	formatSSERegInternal(reg[32:], out)
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| 	fmt.Fprintf(out, "\n\t[%shh] ", "Z"+name[1:])
 | |
| 	formatSSERegInternal(reg[48:], out)
 | |
| 
 | |
| 	return out.String()
 | |
| }
 | |
| 
 | |
| func formatSSERegInternal(xmm []byte, out *bytes.Buffer) {
 | |
| 	buf := bytes.NewReader(xmm)
 | |
| 
 | |
| 	var vi [16]uint8
 | |
| 	for i := range vi {
 | |
| 		binary.Read(buf, binary.LittleEndian, &vi[i])
 | |
| 	}
 | |
| 
 | |
| 	fmt.Fprintf(out, "0x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x", vi[15], vi[14], vi[13], vi[12], vi[11], vi[10], vi[9], vi[8], vi[7], vi[6], vi[5], vi[4], vi[3], vi[2], vi[1], vi[0])
 | |
| 
 | |
| 	fmt.Fprintf(out, "\tv2_int={ %02x%02x%02x%02x%02x%02x%02x%02x %02x%02x%02x%02x%02x%02x%02x%02x }", vi[7], vi[6], vi[5], vi[4], vi[3], vi[2], vi[1], vi[0], vi[15], vi[14], vi[13], vi[12], vi[11], vi[10], vi[9], vi[8])
 | |
| 
 | |
| 	fmt.Fprintf(out, "\tv4_int={ %02x%02x%02x%02x %02x%02x%02x%02x %02x%02x%02x%02x %02x%02x%02x%02x }", vi[3], vi[2], vi[1], vi[0], vi[7], vi[6], vi[5], vi[4], vi[11], vi[10], vi[9], vi[8], vi[15], vi[14], vi[13], vi[12])
 | |
| 
 | |
| 	fmt.Fprintf(out, "\tv8_int={ %02x%02x %02x%02x %02x%02x %02x%02x %02x%02x %02x%02x %02x%02x %02x%02x }", vi[1], vi[0], vi[3], vi[2], vi[5], vi[4], vi[7], vi[6], vi[9], vi[8], vi[11], vi[10], vi[13], vi[12], vi[15], vi[14])
 | |
| 
 | |
| 	fmt.Fprintf(out, "\tv16_int={ %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x }", vi[0], vi[1], vi[2], vi[3], vi[4], vi[5], vi[6], vi[7], vi[8], vi[9], vi[10], vi[11], vi[12], vi[13], vi[14], vi[15])
 | |
| 
 | |
| 	buf.Seek(0, io.SeekStart)
 | |
| 	var v2 [2]float64
 | |
| 	for i := range v2 {
 | |
| 		binary.Read(buf, binary.LittleEndian, &v2[i])
 | |
| 	}
 | |
| 	fmt.Fprintf(out, "\tv2_float={ %g %g }", v2[0], v2[1])
 | |
| 
 | |
| 	buf.Seek(0, io.SeekStart)
 | |
| 	var v4 [4]float32
 | |
| 	for i := range v4 {
 | |
| 		binary.Read(buf, binary.LittleEndian, &v4[i])
 | |
| 	}
 | |
| 	fmt.Fprintf(out, "\tv4_float={ %g %g %g %g }", v4[0], v4[1], v4[2], v4[3])
 | |
| }
 | |
| 
 | |
| func formatX87Reg(b []byte) string {
 | |
| 	if len(b) < 10 {
 | |
| 		return fmt.Sprintf("%#x", b)
 | |
| 	}
 | |
| 	mantissa := binary.LittleEndian.Uint64(b[:8])
 | |
| 	exponent := uint16(binary.LittleEndian.Uint16(b[8:]))
 | |
| 
 | |
| 	var f float64
 | |
| 	fset := false
 | |
| 
 | |
| 	const (
 | |
| 		_SIGNBIT    = 1 << 15
 | |
| 		_EXP_BIAS   = (1 << 14) - 1 // 2^(n-1) - 1 = 16383
 | |
| 		_SPECIALEXP = (1 << 15) - 1 // all bits set
 | |
| 		_HIGHBIT    = 1 << 63
 | |
| 		_QUIETBIT   = 1 << 62
 | |
| 	)
 | |
| 
 | |
| 	sign := 1.0
 | |
| 	if exponent&_SIGNBIT != 0 {
 | |
| 		sign = -1.0
 | |
| 	}
 | |
| 	exponent &= ^uint16(_SIGNBIT)
 | |
| 
 | |
| 	NaN := math.NaN()
 | |
| 	Inf := math.Inf(+1)
 | |
| 
 | |
| 	switch exponent {
 | |
| 	case 0:
 | |
| 		switch {
 | |
| 		case mantissa == 0:
 | |
| 			f = sign * 0.0
 | |
| 			fset = true
 | |
| 		case mantissa&_HIGHBIT != 0:
 | |
| 			f = NaN
 | |
| 			fset = true
 | |
| 		}
 | |
| 	case _SPECIALEXP:
 | |
| 		switch {
 | |
| 		case mantissa&_HIGHBIT == 0:
 | |
| 			f = sign * Inf
 | |
| 			fset = true
 | |
| 		default:
 | |
| 			f = NaN // signaling NaN
 | |
| 			fset = true
 | |
| 		}
 | |
| 	default:
 | |
| 		if mantissa&_HIGHBIT == 0 {
 | |
| 			f = NaN
 | |
| 			fset = true
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	if !fset {
 | |
| 		significand := float64(mantissa) / (1 << 63)
 | |
| 		f = sign * math.Ldexp(significand, int(exponent-_EXP_BIAS))
 | |
| 	}
 | |
| 
 | |
| 	var buf bytes.Buffer
 | |
| 	binary.Write(&buf, binary.LittleEndian, exponent)
 | |
| 	binary.Write(&buf, binary.LittleEndian, mantissa)
 | |
| 
 | |
| 	return fmt.Sprintf("%#04x%016x\t%g", exponent, mantissa, f)
 | |
| }
 |