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Remove: rdtsc and TIC/TOC based on CPU ticks (#11856)

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Use TIC/TOC based on std::chrono instead. This information is also
easier to compare with others, as although it depends on CPU, it
means a bit more if "yours takes 4ms and mine takes 10ms".
This commit is contained in:
Patric Stout
2024-01-21 16:38:15 +01:00
committed by GitHub
parent fe035c306e
commit fa8294ebe7
3 changed files with 4 additions and 105 deletions
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80
src/cpu.cpp
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@@ -12,86 +12,6 @@
#include "safeguards.h"
#undef RDTSC_AVAILABLE
/* rdtsc for MSC_VER, uses simple inline assembly, or _rdtsc
* from external win64.asm because VS2005 does not support inline assembly */
#if defined(_MSC_VER) && !defined(RDTSC_AVAILABLE)
#include <intrin.h>
#include <windows.h>
uint64_t ottd_rdtsc()
{
#if defined(_M_ARM)
return __rdpmccntr64();
#elif defined(_M_ARM64)
return _ReadStatusReg(ARM64_PMCCNTR_EL0);
#else
return __rdtsc();
#endif
}
#define RDTSC_AVAILABLE
#endif
/* rdtsc for all other *nix-en (hopefully). Use GCC syntax */
#if (defined(__i386__) || defined(__x86_64__)) && !defined(RDTSC_AVAILABLE)
uint64_t ottd_rdtsc()
{
uint32_t high, low;
__asm__ __volatile__ ("rdtsc" : "=a" (low), "=d" (high));
return ((uint64_t)high << 32) | low;
}
# define RDTSC_AVAILABLE
#endif
/* rdtsc for PPC which has this not */
#if (defined(__POWERPC__) || defined(__powerpc__)) && !defined(RDTSC_AVAILABLE)
uint64_t ottd_rdtsc()
{
uint32_t high = 0, high2 = 0, low;
/* PPC does not have rdtsc, so we cheat by reading the two 32-bit time-counters
* it has, 'Move From Time Base (Upper)'. Since these are two reads, in the
* very unlikely event that the lower part overflows to the upper part while we
* read it; we double-check and reread the registers */
asm volatile (
"mftbu %0\n"
"mftb %1\n"
"mftbu %2\n"
"cmpw %3,%4\n"
"bne- $-16\n"
: "=r" (high), "=r" (low), "=r" (high2)
: "0" (high), "2" (high2)
);
return ((uint64_t)high << 32) | low;
}
# define RDTSC_AVAILABLE
#endif
/* rdtsc for MCST Elbrus 2000 */
#if defined(__e2k__) && !defined(RDTSC_AVAILABLE)
uint64_t ottd_rdtsc()
{
uint64_t dst;
# pragma asm_inline
asm("rrd %%clkr, %0" : "=r" (dst));
return dst;
}
# define RDTSC_AVAILABLE
#endif
#if defined(__EMSCRIPTEN__) && !defined(RDTSC_AVAILABLE)
/* On emscripten doing TIC/TOC would be ill-advised */
uint64_t ottd_rdtsc() {return 0;}
# define RDTSC_AVAILABLE
#endif
/* In all other cases we have no support for rdtsc. No major issue,
* you just won't be able to profile your code with TIC()/TOC() */
#if !defined(RDTSC_AVAILABLE)
#warning "(non-fatal) No support for rdtsc(), you won't be able to profile with TIC/TOC"
uint64_t ottd_rdtsc() {return 0;}
#endif
/**
* Definitions for CPU detection:
*