mirror of
https://github.com/fluencelabs/wasmer
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82 lines
3.6 KiB
C
82 lines
3.6 KiB
C
/*
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* Copyright 2016 The Emscripten Authors. All rights reserved.
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* Emscripten is available under two separate licenses, the MIT license and the
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* University of Illinois/NCSA Open Source License. Both these licenses can be
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* found in the LICENSE file.
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*/
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#include <stdio.h>
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#include <math.h>
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#include <fenv.h>
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const char *mode(int mode)
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{
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switch(mode)
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{
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case FE_DOWNWARD: return "FE_DOWNWARD";
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case FE_TONEAREST: return "FE_TONEAREST";
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case FE_TOWARDZERO: return "FE_TOWARDZERO";
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case FE_UPWARD: return "FE_UPWARD";
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default: return "Unknown";
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}
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}
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#define NUMELEMS(x) (sizeof((x)) / sizeof((x)[0]))
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int main() {
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printf("Initial rounding mode is %s\n", mode(fegetround()));
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// The functions round() and roundf() are specced to always round *away* from zero (negative numbers down, positive numbers up)
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// fesetround() mode dictates what to do when rounding halfway numbers (-0.5, 0.5, 1.5, 2.5, ...) in functions rint(), rintf(), lrint(), lrintf(), llrint() and llrintf():
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// FE_DOWNWARD always rounds down to the smaller integer.
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// FE_TONEAREST performs banker's rounding (always round towards the even number)
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// FE_TOWARDZERO rounds negative numbers up, and positive numbers down
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// FE_UPWARD always rounds up to the next higher integer.
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// const int modes[] = { FE_DOWNWARD, FE_TONEAREST, FE_TOWARDZERO, FE_UPWARD }; // TODO: Currently only supported mode is FE_TONEAREST.
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const int modes[] = { FE_TONEAREST };
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const double interestingDoubles[] = { -4.5, -3.6, -3.5, -3.4, -2.6, -2.5, -2.4, -1.5, -0.5, 0, 0.5, 1.4, 1.5, 1.6, 2.5, 3.5, 4.5 };
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const float interestingFloats[] = { -4.5f, -3.6f, -3.5f, -3.4f, -2.6f, -2.5f, -2.4f, -1.5f, -0.5f, 0, 0.5f, 1.4f, 1.5f, 1.6f, 2.5f, 3.5f, 4.5f };
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for(int i = 0; i < NUMELEMS(modes); ++i)
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{
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int ret = fesetround(modes[i]);
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int modeAfter = fegetround();
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printf("fesetround(%s) returned %d, fegetround() afterwards returns %s. Test results:\n", mode(modes[i]), ret, mode(modeAfter));
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for(int j = 0; j < NUMELEMS(interestingDoubles); ++j)
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printf("%s: round(%.1f)=%.1f\n", mode(modeAfter), interestingDoubles[j], round(interestingDoubles[j]));
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for(int j = 0; j < NUMELEMS(interestingFloats); ++j)
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printf("%s: roundf(%.1f)=%.1f\n", mode(modeAfter), interestingFloats[j], roundf(interestingFloats[j]));
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for(int j = 0; j < NUMELEMS(interestingDoubles); ++j)
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printf("%s: rint(%.1f)=%.1f\n", mode(modeAfter), interestingDoubles[j], rint(interestingDoubles[j]));
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for(int j = 0; j < NUMELEMS(interestingDoubles); ++j)
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printf("%s: rintf(%.1f)=%.1f\n", mode(modeAfter), interestingFloats[j], rint(interestingFloats[j]));
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for(int j = 0; j < NUMELEMS(interestingDoubles); ++j)
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printf("%s: lrint(%.1f)=%ld\n", mode(modeAfter), interestingDoubles[j], lrint(interestingDoubles[j]));
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for(int j = 0; j < NUMELEMS(interestingDoubles); ++j)
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printf("%s: lrintf(%.1f)=%ld\n", mode(modeAfter), interestingFloats[j], lrintf(interestingFloats[j]));
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for(int j = 0; j < NUMELEMS(interestingDoubles); ++j)
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printf("%s: llrint(%.1f)=%lld\n", mode(modeAfter), interestingDoubles[j], llrint(interestingDoubles[j]));
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for(int j = 0; j < NUMELEMS(interestingDoubles); ++j)
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printf("%s: llrintf(%.1f)=%lld\n", mode(modeAfter), interestingFloats[j], llrintf(interestingFloats[j]));
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}
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double param, fractpart, intpart;
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param = 3.14159265;
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fractpart = modf (param , &intpart);
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printf ("%f = %f + %f\n", param, intpart, fractpart);
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param = -3.14159265;
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fractpart = modf (param , &intpart);
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printf ("%f = %f + %f\n", param, intpart, fractpart);
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return 0;
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}
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