mirror of
https://github.com/golang/go
synced 2024-10-04 16:21:22 -06:00
a46b434931
R=alex.brainman, dave, jsing, gobot, rsc CC=golang-codereviews https://golang.org/cl/35990043
446 lines
9.2 KiB
C
446 lines
9.2 KiB
C
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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#include "runtime.h"
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#include "arch_GOARCH.h"
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#include "../../cmd/ld/textflag.h"
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enum {
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maxround = sizeof(uintptr),
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};
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/*
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* We assume that all architectures turn faults and the like
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* into apparent calls to runtime.sigpanic. If we see a "call"
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* to runtime.sigpanic, we do not back up the PC to find the
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* line number of the CALL instruction, because there is no CALL.
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*/
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void runtime·sigpanic(void);
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// The GOTRACEBACK environment variable controls the
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// behavior of a Go program that is crashing and exiting.
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// GOTRACEBACK=0 suppress all tracebacks
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// GOTRACEBACK=1 default behavior - show tracebacks but exclude runtime frames
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// GOTRACEBACK=2 show tracebacks including runtime frames
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// GOTRACEBACK=crash show tracebacks including runtime frames, then crash (core dump etc)
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int32
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runtime·gotraceback(bool *crash)
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{
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byte *p;
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if(crash != nil)
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*crash = false;
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p = runtime·getenv("GOTRACEBACK");
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if(p == nil || p[0] == '\0')
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return 1; // default is on
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if(runtime·strcmp(p, (byte*)"crash") == 0) {
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if(crash != nil)
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*crash = true;
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return 2; // extra information
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}
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return runtime·atoi(p);
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}
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int32
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runtime·mcmp(byte *s1, byte *s2, uintptr n)
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{
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uintptr i;
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byte c1, c2;
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for(i=0; i<n; i++) {
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c1 = s1[i];
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c2 = s2[i];
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if(c1 < c2)
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return -1;
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if(c1 > c2)
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return +1;
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}
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return 0;
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}
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byte*
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runtime·mchr(byte *p, byte c, byte *ep)
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{
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for(; p < ep; p++)
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if(*p == c)
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return p;
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return nil;
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}
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static int32 argc;
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static uint8** argv;
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Slice os·Args;
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Slice syscall·envs;
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void (*runtime·sysargs)(int32, uint8**);
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void
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runtime·args(int32 c, uint8 **v)
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{
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argc = c;
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argv = v;
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if(runtime·sysargs != nil)
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runtime·sysargs(c, v);
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}
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int32 runtime·isplan9;
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int32 runtime·issolaris;
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int32 runtime·iswindows;
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// Information about what cpu features are available.
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// Set on startup in asm_{x86/amd64}.s.
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uint32 runtime·cpuid_ecx;
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uint32 runtime·cpuid_edx;
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void
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runtime·goargs(void)
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{
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String *s;
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int32 i;
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// for windows implementation see "os" package
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if(Windows)
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return;
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s = runtime·malloc(argc*sizeof s[0]);
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for(i=0; i<argc; i++)
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s[i] = runtime·gostringnocopy(argv[i]);
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os·Args.array = (byte*)s;
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os·Args.len = argc;
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os·Args.cap = argc;
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}
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void
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runtime·goenvs_unix(void)
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{
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String *s;
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int32 i, n;
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for(n=0; argv[argc+1+n] != 0; n++)
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;
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s = runtime·malloc(n*sizeof s[0]);
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for(i=0; i<n; i++)
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s[i] = runtime·gostringnocopy(argv[argc+1+i]);
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syscall·envs.array = (byte*)s;
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syscall·envs.len = n;
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syscall·envs.cap = n;
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}
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void
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runtime·getgoroot(String out)
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{
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byte *p;
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p = runtime·getenv("GOROOT");
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out = runtime·gostringnocopy(p);
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FLUSH(&out);
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}
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int32
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runtime·atoi(byte *p)
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{
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int32 n;
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n = 0;
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while('0' <= *p && *p <= '9')
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n = n*10 + *p++ - '0';
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return n;
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}
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static void
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TestAtomic64(void)
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{
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uint64 z64, x64;
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z64 = 42;
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x64 = 0;
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PREFETCH(&z64);
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if(runtime·cas64(&z64, x64, 1))
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runtime·throw("cas64 failed");
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if(x64 != 0)
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runtime·throw("cas64 failed");
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x64 = 42;
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if(!runtime·cas64(&z64, x64, 1))
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runtime·throw("cas64 failed");
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if(x64 != 42 || z64 != 1)
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runtime·throw("cas64 failed");
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if(runtime·atomicload64(&z64) != 1)
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runtime·throw("load64 failed");
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runtime·atomicstore64(&z64, (1ull<<40)+1);
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if(runtime·atomicload64(&z64) != (1ull<<40)+1)
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runtime·throw("store64 failed");
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if(runtime·xadd64(&z64, (1ull<<40)+1) != (2ull<<40)+2)
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runtime·throw("xadd64 failed");
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if(runtime·atomicload64(&z64) != (2ull<<40)+2)
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runtime·throw("xadd64 failed");
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if(runtime·xchg64(&z64, (3ull<<40)+3) != (2ull<<40)+2)
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runtime·throw("xchg64 failed");
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if(runtime·atomicload64(&z64) != (3ull<<40)+3)
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runtime·throw("xchg64 failed");
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}
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void
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runtime·check(void)
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{
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int8 a;
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uint8 b;
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int16 c;
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uint16 d;
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int32 e;
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uint32 f;
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int64 g;
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uint64 h;
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float32 i, i1;
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float64 j, j1;
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byte *k, *k1;
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uint16* l;
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struct x1 {
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byte x;
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};
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struct y1 {
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struct x1 x1;
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byte y;
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};
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if(sizeof(a) != 1) runtime·throw("bad a");
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if(sizeof(b) != 1) runtime·throw("bad b");
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if(sizeof(c) != 2) runtime·throw("bad c");
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if(sizeof(d) != 2) runtime·throw("bad d");
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if(sizeof(e) != 4) runtime·throw("bad e");
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if(sizeof(f) != 4) runtime·throw("bad f");
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if(sizeof(g) != 8) runtime·throw("bad g");
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if(sizeof(h) != 8) runtime·throw("bad h");
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if(sizeof(i) != 4) runtime·throw("bad i");
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if(sizeof(j) != 8) runtime·throw("bad j");
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if(sizeof(k) != sizeof(uintptr)) runtime·throw("bad k");
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if(sizeof(l) != sizeof(uintptr)) runtime·throw("bad l");
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if(sizeof(struct x1) != 1) runtime·throw("bad sizeof x1");
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if(offsetof(struct y1, y) != 1) runtime·throw("bad offsetof y1.y");
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if(sizeof(struct y1) != 2) runtime·throw("bad sizeof y1");
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if(runtime·timediv(12345LL*1000000000+54321, 1000000000, &e) != 12345 || e != 54321)
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runtime·throw("bad timediv");
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uint32 z;
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z = 1;
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if(!runtime·cas(&z, 1, 2))
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runtime·throw("cas1");
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if(z != 2)
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runtime·throw("cas2");
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z = 4;
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if(runtime·cas(&z, 5, 6))
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runtime·throw("cas3");
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if(z != 4)
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runtime·throw("cas4");
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k = (byte*)0xfedcb123;
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if(sizeof(void*) == 8)
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k = (byte*)((uintptr)k<<10);
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if(runtime·casp((void**)&k, nil, nil))
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runtime·throw("casp1");
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k1 = k+1;
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if(!runtime·casp((void**)&k, k, k1))
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runtime·throw("casp2");
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if(k != k1)
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runtime·throw("casp3");
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*(uint64*)&j = ~0ULL;
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if(j == j)
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runtime·throw("float64nan");
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if(!(j != j))
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runtime·throw("float64nan1");
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*(uint64*)&j1 = ~1ULL;
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if(j == j1)
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runtime·throw("float64nan2");
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if(!(j != j1))
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runtime·throw("float64nan3");
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*(uint32*)&i = ~0UL;
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if(i == i)
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runtime·throw("float32nan");
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if(!(i != i))
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runtime·throw("float32nan1");
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*(uint32*)&i1 = ~1UL;
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if(i == i1)
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runtime·throw("float32nan2");
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if(!(i != i1))
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runtime·throw("float32nan3");
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TestAtomic64();
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}
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void
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runtime·Caller(intgo skip, uintptr retpc, String retfile, intgo retline, bool retbool)
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{
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Func *f, *g;
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uintptr pc;
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uintptr rpc[2];
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/*
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* Ask for two PCs: the one we were asked for
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* and what it called, so that we can see if it
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* "called" sigpanic.
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*/
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retpc = 0;
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if(runtime·callers(1+skip-1, rpc, 2) < 2) {
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retfile = runtime·emptystring;
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retline = 0;
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retbool = false;
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} else if((f = runtime·findfunc(rpc[1])) == nil) {
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retfile = runtime·emptystring;
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retline = 0;
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retbool = true; // have retpc at least
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} else {
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retpc = rpc[1];
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pc = retpc;
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g = runtime·findfunc(rpc[0]);
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if(pc > f->entry && (g == nil || g->entry != (uintptr)runtime·sigpanic))
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pc--;
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retline = runtime·funcline(f, pc, &retfile);
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retbool = true;
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}
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FLUSH(&retpc);
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FLUSH(&retfile);
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FLUSH(&retline);
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FLUSH(&retbool);
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}
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void
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runtime·Callers(intgo skip, Slice pc, intgo retn)
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{
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// runtime.callers uses pc.array==nil as a signal
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// to print a stack trace. Pick off 0-length pc here
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// so that we don't let a nil pc slice get to it.
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if(pc.len == 0)
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retn = 0;
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else
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retn = runtime·callers(skip, (uintptr*)pc.array, pc.len);
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FLUSH(&retn);
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}
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void
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runtime·FuncForPC(uintptr pc, void *retf)
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{
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retf = runtime·findfunc(pc);
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FLUSH(&retf);
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}
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uint32
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runtime·fastrand1(void)
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{
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uint32 x;
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x = m->fastrand;
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x += x;
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if(x & 0x80000000L)
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x ^= 0x88888eefUL;
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m->fastrand = x;
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return x;
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}
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static Lock ticksLock;
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static int64 ticks;
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int64
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runtime·tickspersecond(void)
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{
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int64 res, t0, t1, c0, c1;
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res = (int64)runtime·atomicload64((uint64*)&ticks);
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if(res != 0)
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return ticks;
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runtime·lock(&ticksLock);
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res = ticks;
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if(res == 0) {
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t0 = runtime·nanotime();
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c0 = runtime·cputicks();
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runtime·usleep(100*1000);
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t1 = runtime·nanotime();
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c1 = runtime·cputicks();
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if(t1 == t0)
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t1++;
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res = (c1-c0)*1000*1000*1000/(t1-t0);
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if(res == 0)
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res++;
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runtime·atomicstore64((uint64*)&ticks, res);
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}
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runtime·unlock(&ticksLock);
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return res;
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}
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void
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runtime∕pprof·runtime_cyclesPerSecond(int64 res)
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{
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res = runtime·tickspersecond();
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FLUSH(&res);
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}
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DebugVars runtime·debug;
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static struct {
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int8* name;
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int32* value;
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} dbgvar[] = {
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{"allocfreetrace", &runtime·debug.allocfreetrace},
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{"efence", &runtime·debug.efence},
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{"gctrace", &runtime·debug.gctrace},
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{"scheddetail", &runtime·debug.scheddetail},
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{"schedtrace", &runtime·debug.schedtrace},
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};
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void
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runtime·parsedebugvars(void)
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{
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byte *p;
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intgo i, n;
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p = runtime·getenv("GODEBUG");
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if(p == nil)
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return;
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for(;;) {
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for(i=0; i<nelem(dbgvar); i++) {
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n = runtime·findnull((byte*)dbgvar[i].name);
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if(runtime·mcmp(p, (byte*)dbgvar[i].name, n) == 0 && p[n] == '=')
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*dbgvar[i].value = runtime·atoi(p+n+1);
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}
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p = runtime·strstr(p, (byte*)",");
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if(p == nil)
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break;
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p++;
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}
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}
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// Poor mans 64-bit division.
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// This is a very special function, do not use it if you are not sure what you are doing.
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// int64 division is lowered into _divv() call on 386, which does not fit into nosplit functions.
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// Handles overflow in a time-specific manner.
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#pragma textflag NOSPLIT
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int32
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runtime·timediv(int64 v, int32 div, int32 *rem)
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{
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int32 res, bit;
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if(v >= (int64)div*0x7fffffffLL) {
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if(rem != nil)
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*rem = 0;
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return 0x7fffffff;
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}
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res = 0;
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for(bit = 30; bit >= 0; bit--) {
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if(v >= ((int64)div<<bit)) {
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v = v - ((int64)div<<bit);
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res += 1<<bit;
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}
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}
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if(rem != nil)
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*rem = v;
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return res;
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}
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