| 1 | // RUN: %clangxx_nsan -O2 -g %s -o %t |
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| 2 | // RUN: env NSAN_OPTIONS=check_cmp=true,halt_on_error=0 %run %t 2>&1 | FileCheck %s -check-prefix=CMP_ENABLE |
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| 3 | // RUN: env NSAN_OPTIONS=check_cmp=false,halt_on_error=0 %run %t 2>&1 | FileCheck %s -check-prefix=CMP_DISABLE |
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| 4 | |
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| 5 | #include <cmath> |
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| 6 | #include <cstdio> |
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| 7 | |
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| 8 | // 0.6/0.2 is slightly below 3, so the comparison will fail after a certain |
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| 9 | // threshold that depends on the precision of the computation. |
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| 10 | __attribute__((noinline)) // To check call stack reporting. |
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| 11 | bool DoCmp(double a, double b, double c, double threshold) { |
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| 12 | return c - a / b < threshold; |
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| 13 | // CMP_ENABLE: WARNING: NumericalStabilitySanitizer: floating-point comparison results depend on precision |
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| 14 | // CMP_ENABLE: double {{ *}}precision dec (native): {{.*}}<{{.*}} |
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| 15 | // CMP_ENABLE: __float128{{ *}}precision dec (shadow): {{.*}}<{{.*}} |
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| 16 | // CMP_ENABLE: {{#0 .*in DoCmp}} |
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| 17 | } |
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| 18 | |
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| 19 | int main() { |
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| 20 | double threshold = 1.0; |
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| 21 | for (int i = 0; i < 60; ++i) { |
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| 22 | threshold /= 2; |
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| 23 | // CMP_DISABLE: value at threshold {{.*}} |
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| 24 | printf("value at threshold %.20f: %i\n" , threshold, |
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| 25 | DoCmp(a: 0.6, b: 0.2, c: 3.0, threshold)); |
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| 26 | } |
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| 27 | return 0; |
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| 28 | } |
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| 29 | |
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